000
FXUS66 KPDT 201608
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
808 AM PST TUE JAN 20 2009
.UPDATE...LOW CLOUDS AND FOG/FREEZING FOG CONTINUE BELOW 3500 FEET
IN THE LOWER COLUMBIA BASIN AND ADJACENT VALLEYS...JOHN DAY
VALLEY...AND DESCHUTES PLATEAU. PLAN TO EXTEND ALL FREEZING FOG
ADVISORIES LATER EXCEPT WALLOWA COUNTY UNTIL NOON WEDNESDAY. IN
WALLOWA COUNTY THE FOG COVERAGE IS VERY LIMITED. IN DESCHUTES
COUNTY THE FOG AND STRATUS WILL BREAK UP BRIEFLY IN THE
AFTERNOON...BUT RETURN TONIGHT. THE OTHER AREAS WILL HAVE THE
FREEZING FOG ABOVE 2000-2500 FEET WHERE THE CLOUDS REACH THE
GROUND. SINCE THIS WILL AFFECT PARTS OF I-90 IN KITTITAS
VALLEY...I-82 BETWEEN YAKIMA AND ELLENSBURG...I-84 BETWEEN
PENDLETON AND MEACHAM...AND OTHER HIGHWAYS IN THE MOUNTAINS IT IS
SIGNIFICANT EVEN THOUGH IT PROBABLY WILL NOT BE WIDESPREAD OR IMPACT
HEAVILY POPULATED AREAS. COONFIELD
&&
.PREV DISCUSSION... /ISSUED 245 AM PST TUE JAN 20 2009/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...A STRONG AND HIGHLY
AMPLIFIED HIGH PRESSURE RIDGE WILL REMAIN OVER THE PACIFIC NORTHWEST
AND THE FORECAST AREA THROUGH WEDNESDAY. STRONG TEMPERATURE
INVERSIONS WILL CAUSE WIDESPREAD LOW STRATUS CLOUDS WITH AREAS OF
FOG NEAR THE EDGES OF THE STRATUS DECK TO PERSIST IN THE LOWER
COLUMBIA BASIN AND CONNECTING VALLEYS. IN THESE AREAS THERE WILL BE
LITTLE DIURNAL TEMPERATURE CHANGE...BY ONLY A FEW DEGREES AND POOR
MIXING. THE STRATUS AND/OR FOG MAY DECREASE OR THIN OUT DURING THE
AFTERNOONS IN AREAS SUCH AS REDMOND/BEND OREGON...THE BLUE MOUNTAIN
FOOTHILLS AND THE CASCADE EAST SLOPES WHERE THE STRATUS LAYER MEETS
THE TERRAIN. THESE AREAS MAY SEE MORE DIURNAL CHANGE IN TEMPERATURE
BUT MAY ALSO EXPERIENCE DENSE FREEZING FOG AT TIMES. AS SUCH A
FREEZING FOG ADVISORY WILL REMAIN IN EFFECT FOR THESE AREAS THROUGH
AT LEAST THIS MORNING. IN ADDITION AN AIR STAGNATION ADVISORY WILL
REMAIN IN EFFECT DUE TO VERY POOR MIXING OF TRAPPED POLLUTANTS AND
PARTICULATE MATTER UNDER THE INVERSIONS. IN THE HIGHER ELEVATIONS
ONLY A FEW HIGH CLOUDS WILL BE PRESENT. THERE WILL BE MUCH GREATER
DIURNAL TEMPERATURE CHANGE WITH ABOVE NORMAL READINGS BEING
WIDESPREAD DURING THE DAY TIME. BY WEDNESDAY NIGHT INTO EARLY
THURSDAY A CLOSED UPPER LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC
WILL UNDERCUT THE UPPER RIDGE AND CAUSE A SPLIT FLOW TO DEVELOP OVER
THE REGION. THIS WILL ALLOW SLIGHTLY BETTER MIXING TO TAKE PLACE
WITH WEAKENING INVERSIONS. IN THE HIGHER ELEVATIONS INCREASING MID
AND HIGH CLOUDS WILL OCCUR. 88
LONG TERM...THURSDAY THROUGH MONDAY...A DISTURBANCE OVER CALIFORNIA
WILL MOVE NORTHWARD...SPREADING PRECIPITATION INTO SOUTHERN AND
CENTRAL OREGON THURSDAY AND THURSDAY NIGHT. A LOW PRESSURE SYSTEM IN
THE EASTERN PACIFIC WILL SEND OTHER DISTURBANCES INTO THE PACIFIC
NORTHWEST INTO THE WEEKEND...WITH A CHANCE OF SHOWERS FOR MAINLY THE
HIGHER TERRAIN. THESE DISTURBANCES DO NOT LOOK STRONG ENOUGH TO MIX
OUT THE STRONG TEMPERATURE INVERSION IN PLACE OVER THE LOWER
ELEVATIONS. THE FOG AND LOW STRATUS WILL THEN CONTINUE OVER THE
COLUMBIA BASIN AND SURROUNDING VALLEYS AT LEAST INTO THE WEEKEND.
THE FOG MAY BURN OFF IN CENTRAL OREGON AND THE JOHN DAY VALLEY WITH
THIS SYSTEM ON THURSDAY...AND LEAD TO TEMPERATURES CLOSER TO NORMAL.
MODELS BEGIN TO DISAGREE OVER THE WEEKEND AND INTO NEXT WEEK. HAVE
LEANED TOWARD THE MORE CONSISTENT EUROPEAN MODEL...KEEPING A
NORTHWEST FLOW OVER THE REGION...WITH WEATHER DISTURBANCES MOVING
THROUGH THE FLOW. THESE DISTURBANCES WILL BRING A CHANCE OF SNOW
SHOWERS TO THE MOUNTAINS AND RAIN AND SNOW SHOWERS TO THE LOWER
ELEVATIONS. THERE IS A CHANCE THAT THE SYSTEM ON SATURDAY MAY HELP
SCOUR OUT THE FOG AND STRATUS OVER THE BASIN...AS THERE IS SOME
INCREASE IN THE WINDS AND COOLER AIR ALOFT WILL FILTER IN. DMH
AVIATION...12Z TAFS. MVFR AND OCCASIONAL IFR CONDITIONS IN MAINLY
LOW CEILINGS WILL CONTINUE FOR THE NEXT 24 HOURS AT ALL TAF SITES
EXCEPT KRDM. KRDM WILL SEE IFR CONDITIONS IN LOW CEILINGS INTO THE
MORNING HOURS BEFORE IMPROVING TO VFR BY THE AFTERNOON AS THE FOG
BURNS OFF. SURFACE WINDS ARE EXPECTED TO REMAIN BELOW 10 KTS. DMH
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 30 27 33 28 / 0 0 10 10
ALW 30 28 33 29 / 0 0 10 10
PSC 30 29 34 30 / 0 0 10 10
YKM 31 25 34 26 / 0 0 10 10
HRI 30 28 34 29 / 0 0 10 10
ELN 32 23 34 25 / 0 0 10 10
RDM 32 22 34 24 / 0 0 10 10
LGD 35 23 35 25 / 0 0 10 10
GCD 29 22 31 24 / 0 0 10 10
DLS 34 30 38 30 / 0 0 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042-
050-501-504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
76/99/99
000
FXUS66 KPDT 201042 AAA
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
245 AM PST TUE JAN 20 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...A STRONG AND HIGHLY
AMPLIFIED HIGH PRESSURE RIDGE WILL REMAIN OVER THE PACIFIC NORTHWEST
AND THE FORECAST AREA THROUGH WEDNESDAY. STRONG TEMPERATURE
INVERSIONS WILL CAUSE WIDESPREAD LOW STRATUS CLOUDS WITH AREAS OF
FOG NEAR THE EDGES OF THE STRATUS DECK TO PERSIST IN THE LOWER
COLUMBIA BASIN AND CONNECTING VALLEYS. IN THESE AREAS THERE WILL BE
LITTLE DIURNAL TEMPERATURE CHANGE...BY ONLY A FEW DEGREES AND POOR
MIXING. THE STRATUS AND/OR FOG MAY DECREASE OR THIN OUT DURING THE
AFTERNOONS IN AREAS SUCH AS REDMOND/BEND OREGON...THE BLUE MOUNTAIN
FOOTHILLS AND THE CASCADE EAST SLOPES WHERE THE STRATUS LAYER MEETS
THE TERRAIN. THESE AREAS MAY SEE MORE DIURNAL CHANGE IN TEMPERATURE
BUT MAY ALSO EXPERIENCE DENSE FREEZING FOG AT TIMES. AS SUCH A
FREEZING FOG ADVISORY WILL REMAIN IN EFFECT FOR THESE AREAS THROUGH
AT LEAST THIS MORNING. IN ADDITION AN AIR STAGNATION ADVISORY WILL
REMAIN IN EFFECT DUE TO VERY POOR MIXING OF TRAPPED POLLUTANTS AND
PARTICULATE MATTER UNDER THE INVERSIONS. IN THE HIGHER ELEVATIONS
ONLY A FEW HIGH CLOUDS WILL BE PRESENT. THERE WILL BE MUCH GREATER
DIURNAL TEMPERATURE CHANGE WITH ABOVE NORMAL READINGS BEING
WIDESPREAD DURING THE DAY TIME. BY WEDNESDAY NIGHT INTO EARLY
THURSDAY A CLOSED UPPER LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC
WILL UNDERCUT THE UPPER RIDGE AND CAUSE A SPLIT FLOW TO DEVELOP OVER
THE REGION. THIS WILL ALLOW SLIGHTLY BETTER MIXING TO TAKE PLACE
WITH WEAKENING INVERSIONS. IN THE HIGHER ELEVATIONS INCREASING MID
AND HIGH CLOUDS WILL OCCUR. 88
.LONG TERM...THURSDAY THROUGH MONDAY...A DISTURBANCE OVER CALIFORNIA
WILL MOVE NORTHWARD...SPREADING PRECIPITATION INTO SOUTHERN AND
CENTRAL OREGON THURSDAY AND THURSDAY NIGHT. A LOW PRESSURE SYSTEM IN
THE EASTERN PACIFIC WILL SEND OTHER DISTURBANCES INTO THE PACIFIC
NORTHWEST INTO THE WEEKEND...WITH A CHANCE OF SHOWERS FOR MAINLY THE
HIGHER TERRAIN. THESE DISTURBANCES DO NOT LOOK STRONG ENOUGH TO MIX
OUT THE STRONG TEMPERATURE INVERSION IN PLACE OVER THE LOWER
ELEVATIONS. THE FOG AND LOW STRATUS WILL THEN CONTINUE OVER THE
COLUMBIA BASIN AND SURROUNDING VALLEYS AT LEAST INTO THE WEEKEND.
THE FOG MAY BURN OFF IN CENTRAL OREGON AND THE JOHN DAY VALLEY WITH
THIS SYSTEM ON THURSDAY...AND LEAD TO TEMPERATURES CLOSER TO NORMAL.
MODELS BEGIN TO DISAGREE OVER THE WEEKEND AND INTO NEXT WEEK. HAVE
LEANED TOWARD THE MORE CONSISTENT EUROPEAN MODEL...KEEPING A
NORTHWEST FLOW OVER THE REGION...WITH WEATHER DISTURBANCES MOVING
THROUGH THE FLOW. THESE DISTURBANCES WILL BRING A CHANCE OF SNOW
SHOWERS TO THE MOUNTAINS AND RAIN AND SNOW SHOWERS TO THE LOWER
ELEVATIONS. THERE IS A CHANCE THAT THE SYSTEM ON SATURDAY MAY HELP
SCOUR OUT THE FOG AND STRATUS OVER THE BASIN...AS THERE IS SOME
INCREASE IN THE WINDS AND COOLER AIR ALOFT WILL FILTER IN. DMH
&&
.AVIATION...12Z TAFS. MVFR AND OCCASIONAL IFR CONDITIONS IN MAINLY
LOW CEILINGS WILL CONTINUE FOR THE NEXT 24 HOURS AT ALL TAF SITES
EXCEPT KRDM. KRDM WILL SEE IFR CONDITIONS IN LOW CEILINGS INTO THE
MORNING HOURS BEFORE IMPROVING TO VFR BY THE AFTERNOON AS THE FOG
BURNS OFF. SURFACE WINDS ARE EXPECTED TO REMAIN BELOW 10 KTS. DMH
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 30 27 33 28 / 0 0 10 10
ALW 30 28 33 29 / 0 0 10 10
PSC 30 29 34 30 / 0 0 10 10
YKM 31 25 34 26 / 0 0 10 10
HRI 30 28 34 29 / 0 0 10 10
ELN 32 23 34 25 / 0 0 10 10
RDM 32 22 34 24 / 0 0 10 10
LGD 35 23 35 25 / 0 0 10 10
GCD 29 22 31 24 / 0 0 10 10
DLS 34 30 38 30 / 0 0 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042-
050-501-504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
88/84/94
000
FXUS66 KPDT 201019
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
215 AM PST TUE JAN 20 2009
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...A STRONG AND HIGHLY
AMPLIFIED HIGH PRESSURE RIDGE WILL REMAIN OVER THE PACIFIC NORTHWEST
AND THE FORECAST AREA THROUGH WEDNESDAY. STRONG TEMPERATURE
INVERSIONS WILL CAUSE WIDESPREAD LOW STRATUS CLOUDS WITH AREAS OF
FOG NEAR THE EDGES OF THE STRATUS DECK TO PERSIST IN THE LOWER
COLUMBIA BASIN AND CONNECTING VALLEYS. IN THESE AREAS THERE WILL BE
LITTLE DIURNAL TEMPERATURE CHANGE...BY ONLY A FEW DEGREES AND POOR
MIXING. THE STRATUS AND/OR FOG MAY DECREASE OR THIN OUT DURING THE
AFTERNOONS IN AREAS SUCH AS REDMOND/BEND OREGON...THE BLUE MOUNTAIN
FOOTHILLS AND THE CASCADE EAST SLOPES WHERE THE STRATUS LAYER MEETS
THE TERRAIN. THESE AREAS MAY SEE MORE DIURNAL CHANGE IN TEMPERATURE
BUT MAY ALSO EXPERIENCE DENSE FREEZING FOG AT TIMES. AS SUCH A
FREEZING FOG ADVISORY WILL REMAIN IN EFFECT FOR THESE AREAS THROUGH
AT LEAST THIS MORNING. IN ADDITION AN AIR STAGNATION ADVISORY WILL
REMAIN IN EFFECT DUE TO VERY POOR MIXING OF TRAPPED POLLUTANTS AND
PARTICULATE MATTER UNDER THE INVERSIONS. IN THE HIGHER ELEVATIONS
ONLY A FEW HIGH CLOUDS WILL BE PRESENT. THERE WILL BE MUCH GREATER
DIURNAL TEMPERATURE CHANGE WITH ABOVE NORMAL READINGS BEING
WIDESPREAD DURING THE DAY TIME. BY WEDNESDAY NIGHT INTO EARLY
THURSDAY A CLOSED UPPER LOW PRESSURE SYSTEM OVER THE EASTERN PACIFIC
WILL UNDERCUT THE UPPER RIDGE AND CAUSE A SPLIT FLOW TO DEVELOP OVER
THE REGION. THIS WILL ALLOW SLIGHTLY BETTER MIXING TO TAKE PLACE
WITH WEAKENING INVERSIONS. IN THE HIGHER ELEVATIONS INCREASING MID
AND HIGH CLOUDS WILL OCCUR. 88
.LONG TERM...THURSDAY THROUGH MONDAY...A DISTURBANCE OVER CALIFORNIA
WILL MOVE NORTHWARD...SPREADING PRECIPITATION INTO SOUTHERN AND
CENTRAL OREGON THURSDAY AND THURSDAY NIGHT. A LOW PRESSURE SYSTEM IN
THE EASTERN PACIFIC WILL SEND OTHER DISTURBANCES INTO THE PACIFIC
NORTHWEST INTO THE WEEKEND...WITH A CHANCE OF SHOWERS FOR MAINLY THE
HIGHER TERRAIN. THESE DISTURBANCES DO NOT LOOK STRONG ENOUGH TO MIX
OUT THE STRONG TEMPERATURE INVERSION IN PLACE OVER THE LOWER
ELEVATIONS. THE FOG AND LOW STRATUS WILL THEN CONTINUE OVER THE
COLUMBIA BASIN AND SURROUNDING VALLEYS AT LEAST INTO THE WEEKEND.
THE FOG MAY BURN OFF IN CENTRAL OREGON AND THE JOHN DAY VALLEY WITH
THIS SYSTEM ON THURSDAY...AND LEAD TO TEMPERATURES CLOSER TO NORMAL.
MODELS BEGIN TO DISAGREE OVER THE WEEKEND AND INTO NEXT WEEK. HAVE
LEANED TOWARD THE MORE CONSISTENT EUROPEAN MODEL...KEEPING A
NORTHWEST FLOW OVER THE REGION...WITH WEATHER DISTURBANCES MOVING
THROUGH THE FLOW. THESE DISTURBANCES WILL BRING A CHANCE OF SNOW
SHOWERS TO THE MOUNTAINS AND RAIN AND SNOW SHOWERS TO THE LOWER
ELEVATIONS. THERE IS A CHANCE THAT THE SYSTEM ON SATURDAY MAY HELP
SCOUR OUT THE FOG AND STRATUS OVER THE BASIN...AS THERE IS SOME
INCREASE IN THE WINDS AND COOLER AIR ALOFT WILL FILTER IN. DMH
&&
.PREVIOUS AVIATION DISCUSSION...06Z TAFS. MVFR AND OCCASIONAL IFR
CONDITIONS FOR THE NEXT 24 HOURS AT YKM PSC ALW DLS PDT. CEILINGS
WILL CONTINUE AT 008-025. THE EXCEPTION WILL BE RDM WHERE CONDITIONS
WILL BE LIFR IN FOG TONIGHT THEN IMPROVE TO VFR TUESDAY AFTERNOON.
SURFACE WINDS LESS THAN 10 KT. 94
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 30 27 33 28 / 0 0 10 10
ALW 30 28 33 29 / 0 0 10 10
PSC 30 29 34 30 / 0 0 10 10
YKM 31 25 34 26 / 0 0 10 10
HRI 30 28 34 29 / 0 0 10 10
ELN 32 23 34 25 / 0 0 10 10
RDM 32 22 34 24 / 0 0 10 10
LGD 35 23 35 25 / 0 0 10 10
GCD 29 22 31 24 / 0 0 10 10
DLS 34 30 38 30 / 0 0 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042-
050-501-504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL NOON PST TODAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
88/84/94
000
FXUS66 KPDT 200555
AFDPDT
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PENDLETON OR
955 PM PST MON JAN 19 2009
.SHORT TERM...NO CHANGE TO THE WEATHER PATTERN FOR TONIGHT AND
TUESDAY AS UPPER RIDGE REMAINS IN PLACE. CONDITIONS WILL REMAIN VERY
SIMILAR AS FAR AS CLOUD COVER AND TEMPERATURES ARE CONCERNED. AREAS
TRAPPED UNDER A STRONG LOW LEVEL INVERSION IN THE STRATUS AND FOG
WILL SEE ONLY ABOUT 1-4 DEGREES OF DIURNAL TEMPERATURE CHANGE WITH
CALM WINDS. THE REMAINDER OF THE FORECAST AREA WILL SEE A LARGER
TEMPERATURE SPREAD UNDER PARTLY CLOUDY SKIES AS SOME CIRRUS IS
MOVING THROUGH. 94
.AVIATION...06Z TAFS. MVFR AND OCCASIONAL IFR CONDITIONS FOR THE
NEXT 24 HOURS AT YKM PSC ALW DLS PDT. CEILINGS WILL CONTINUE AT
008-025. THE EXCEPTION WILL BE RDM WHERE CONDITIONS WILL BE LIFR IN
FOG TONIGHT THEN IMPROVE TO VFR TUESDAY AFTERNOON. SURFACE WINDS
LESS THAN 10 KT. 94
&&
.PREV DISCUSSION... /ISSUED 337 PM PST MON JAN 19 2009/
SHORT TERM...TONIGHT THROUGH THURSDAY...AN UPPER LEVEL RIDGE WILL
DRIFT SLOWLY EAST TONIGHT THROUGH WEDNESDAY. THIS WILL KEEP STRONG
SURFACE INVERSIONS IN THE LOWER COLUMBIA BASIN AND ADJACENT
VALLEYS...WITH GENERALLY LIGHT WINDS OVER ALL OF EASTERN WASHINGTON
AND OREGON. DIURNAL TEMPERATURE RANGES WILL REMAIN SMALL IN THE
AREAS OF LOW CLOUDS AND FOG. THE AREA OF LOW CLOUDS AND FOG WILL
SLOWLY CONTRACT IN SIZE AS WARM SOUTHERLY FLOW STRENGTHENS THE TOP
OF THE SURFACE INVERSIONS AND LOWERS THE THICKER FREEZING FOG AGAIN.
THIS WILL ALLOW CENTRAL OREGON AND AREAS ABOVE 2500 FEET IN NORTH
CENTRAL OREGON TO BREAK OUT OF THE FOG AND LOW STRATUS TOMORROW
AFTERNOON AND HAVE WARMER HIGH TEMPERATURES...WHILE LOWER ELEVATIONS
WILL SEE MORE THICKER FOG REDUCING VISIBILITY. WEDNESDAY NIGHT AND
THURSDAY A CUTOFF LOW IN CALIFORNIA WILL UNCUT THE WEAKENING
RIDGE...AND MAY TRIGGER A FEW SHOWERS IN THE OREGON MOUNTAINS WHERE
OROGRAPHIC LIFTING WILL ENHANCE INSTABILITY ASSOCIATED WITH THE LOW.
THE MODELS DO NOT SHOW ENOUGH WIND TO BREAK UP THE LOW LEVEL
INVERSIONS EXCEPT IN CENTRAL OREGON AND JOHN DAY VALLEY...BUT THE
INVERSIONS WILL BECOME WEAKER WITH COLDER AIR ALOFT. WILL EXTEND THE
CURRENT AIR STAGNATION ADVISORY SHORTLY UNTIL THURSDAY AFTERNOON TO
COVER THIS CONTINUING SITUATION. COONFIELD
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...MODELS ARE COMING INTO
BETTER AGREEMENT DURING THE LONG TERM PERIOD. BOTH THE GFS AND ECMWF
BRING AN UPPER LOW SOUTH ALONG THE PACIFIC NORTHWEST COAST THURSDAY
NIGHT THROUGH FRIDAY NIGHT. CIRCULATION AROUND THE LOW BUILDS SOME
MILD RIDGING OVER THE AREA. THE LOW DOES NOT SEND AN ORGANIZED FRONT
THROUGH THE AREA. THE SITUATION DOES NOT LOOK STRONG ENOUGH TO ME TO
SCOUR OUT THE COLD AIR IN THE COLUMBIA BASIN SO HAVE HELD ONTO THE
LOW CLOUDS AND FOG THROUGH THIS PERIOD. HAVE THEREFORE KEPT
TEMPERATURES IN THE COLUMBIA BASIN AND ADJACENT LOWLANDS IN A NARROW
RANGE FROM THE MID 20S TO MID 30S. HOWEVER...THE SITUATION IS FAIRLY
TRICKY AND CONFIDENCE IN THE CONTINUATION OF THE LOW CLOUDS AND FOG
IS NOT HIGH AFTER THURSDAY NIGHT. ELSEWHERE IN THE AREA...THE
RIDGING SHOULD WARM TEMPERATURES SO HAVE NUDGED THEM UP A BIT INTO
THE LOWER 40S FOR THE BEND AREA. BOTH MODELS SEND SOME PRECIPITATION
INTO THE SOUTHERN HALF OF THE AREA FRIDAY AND FRIDAY NIGHT SO HAVE
SOME RAIN AND SNOW SHOWERS MAINLY IN THE MOUNTAINS AND EXPANDED IT
OUT OF THE MOUNTAINS ON SATURDAY. BY SATURDAY NIGHT THE LOW HAS
MOVED SOUTH OUT OF THE AREA AND A TROUGH MOVES IN WITH A COOL NORTH
TO NORTHWEST FLOW THROUGH MONDAY. MODELS DIFFER AS THE NATURE OF THE
TROUGH. THE ECMWF HAS A MORE NORTHWESTERLY FLOW OFF THE PACIFIC
WHILE THE GFS IS MORE NORTHERLY AND STILL TRYING TO WORK SOME ARCTIC
AIR IN OUT OF CANADA BUT TO A LESSER DEGREE THAN EARLIER RUNS. HAVE
SIDED WITH THE ECMWF BUT COOLED TEMPS A BIT TOWARDS THE GFS. WITH
THE TROUGH IN PLACE A SERIES OF DISTURBANCE WILL BRING A CHANCE OF
SNOW TO THE MOUNTAINS AND A SLIGHT CHANCE OF RAIN AND SNOW SATURDAY
NIGHT THROUGH MONDAY. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 27 31 25 35 / 0 0 0 10
ALW 28 33 26 33 / 0 0 0 10
PSC 29 36 27 33 / 0 0 0 10
YKM 26 33 23 36 / 0 0 0 10
HRI 28 33 26 34 / 0 0 0 10
ELN 26 32 21 37 / 0 0 0 10
RDM 22 38 20 45 / 0 0 0 10
LGD 23 36 21 40 / 0 0 0 10
GCD 21 38 20 45 / 0 0 0 10
DLS 30 36 28 37 / 0 0 0 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
94/
000
FXUS66 KPDT 200401
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
800 PM PST MON JAN 19 2009
.SHORT TERM...NO CHANGE TO THE WEATHER PATTERN FOR TONIGHT AND
TUESDAY AS UPPER RIDGE REMAINS IN PLACE. CONDITIONS WILL REMAIN VERY
SIMILAR AS FAR AS CLOUD COVER AND TEMPERATURES ARE CONCERNED. AREAS
TRAPPED UNDER A STRONG LOW LEVEL INVERSION IN THE STRATUS AND FOG
WILL SEE ONLY ABOUT 1-4 DEGREES OF DIURNAL TEMPERATURE CHANGE WITH
CALM WINDS. THE REMAINDER OF THE FORECAST AREA WILL SEE A LARGER
TEMPERATURE SPREAD UNDER PARTLY CLOUDY SKIES AS SOME CIRRUS IS
MOVING THROUGH. 94
&&
.PREV DISCUSSION... /ISSUED 337 PM PST MON JAN 19 2009/
SHORT TERM...TONIGHT THROUGH THURSDAY...AN UPPER LEVEL RIDGE WILL
DRIFT SLOWLY EAST TONIGHT THROUGH WEDNESDAY. THIS WILL KEEP STRONG
SURFACE INVERSIONS IN THE LOWER COLUMBIA BASIN AND ADJACENT
VALLEYS...WITH GENERALLY LIGHT WINDS OVER ALL OF EASTERN WASHINGTON
AND OREGON. DIURNAL TEMPERATURE RANGES WILL REMAIN SMALL IN THE
AREAS OF LOW CLOUDS AND FOG. THE AREA OF LOW CLOUDS AND FOG WILL
SLOWLY CONTRACT IN SIZE AS WARM SOUTHERLY FLOW STRENGTHENS THE TOP
OF THE SURFACE INVERSIONS AND LOWERS THE THICKER FREEZING FOG AGAIN.
THIS WILL ALLOW CENTRAL OREGON AND AREAS ABOVE 2500 FEET IN NORTH
CENTRAL OREGON TO BREAK OUT OF THE FOG AND LOW STRATUS TOMORROW
AFTERNOON AND HAVE WARMER HIGH TEMPERATURES...WHILE LOWER ELEVATIONS
WILL SEE MORE THICKER FOG REDUCING VISIBILITY. WEDNESDAY NIGHT AND
THURSDAY A CUTOFF LOW IN CALIFORNIA WILL UNCUT THE WEAKENING
RIDGE...AND MAY TRIGGER A FEW SHOWERS IN THE OREGON MOUNTAINS WHERE
OROGRAPHIC LIFTING WILL ENHANCE INSTABILITY ASSOCIATED WITH THE LOW.
THE MODELS DO NOT SHOW ENOUGH WIND TO BREAK UP THE LOW LEVEL
INVERSIONS EXCEPT IN CENTRAL OREGON AND JOHN DAY VALLEY...BUT THE
INVERSIONS WILL BECOME WEAKER WITH COLDER AIR ALOFT. WILL EXTEND THE
CURRENT AIR STAGNATION ADVISORY SHORTLY UNTIL THURSDAY AFTERNOON TO
COVER THIS CONTINUING SITUATION. COONFIELD
LONG TERM...THURSDAY NIGHT THROUGH MONDAY...MODELS ARE COMING INTO
BETTER AGREEMENT DURING THE LONG TERM PERIOD. BOTH THE GFS AND ECMWF
BRING AN UPPER LOW SOUTH ALONG THE PACIFIC NORTHWEST COAST THURSDAY
NIGHT THROUGH FRIDAY NIGHT. CIRCULATION AROUND THE LOW BUILDS SOME
MILD RIDGING OVER THE AREA. THE LOW DOES NOT SEND AN ORGANIZED FRONT
THROUGH THE AREA. THE SITUATION DOES NOT LOOK STRONG ENOUGH TO ME TO
SCOUR OUT THE COLD AIR IN THE COLUMBIA BASIN SO HAVE HELD ONTO THE
LOW CLOUDS AND FOG THROUGH THIS PERIOD. HAVE THEREFORE KEPT
TEMPERATURES IN THE COLUMBIA BASIN AND ADJACENT LOWLANDS IN A NARROW
RANGE FROM THE MID 20S TO MID 30S. HOWEVER...THE SITUATION IS FAIRLY
TRICKY AND CONFIDENCE IN THE CONTINUATION OF THE LOW CLOUDS AND FOG
IS NOT HIGH AFTER THURSDAY NIGHT. ELSEWHERE IN THE AREA...THE
RIDGING SHOULD WARM TEMPERATURES SO HAVE NUDGED THEM UP A BIT INTO
THE LOWER 40S FOR THE BEND AREA. BOTH MODELS SEND SOME PRECIPITATION
INTO THE SOUTHERN HALF OF THE AREA FRIDAY AND FRIDAY NIGHT SO HAVE
SOME RAIN AND SNOW SHOWERS MAINLY IN THE MOUNTAINS AND EXPANDED IT
OUT OF THE MOUNTAINS ON SATURDAY. BY SATURDAY NIGHT THE LOW HAS
MOVED SOUTH OUT OF THE AREA AND A TROUGH MOVES IN WITH A COOL NORTH
TO NORTHWEST FLOW THROUGH MONDAY. MODELS DIFFER AS THE NATURE OF THE
TROUGH. THE ECMWF HAS A MORE NORTHWESTERLY FLOW OFF THE PACIFIC
WHILE THE GFS IS MORE NORTHERLY AND STILL TRYING TO WORK SOME ARCTIC
AIR IN OUT OF CANADA BUT TO A LESSER DEGREE THAN EARLIER RUNS. HAVE
SIDED WITH THE ECMWF BUT COOLED TEMPS A BIT TOWARDS THE GFS. WITH
THE TROUGH IN PLACE A SERIES OF DISTURBANCE WILL BRING A CHANCE OF
SNOW TO THE MOUNTAINS AND A SLIGHT CHANCE OF RAIN AND SNOW SATURDAY
NIGHT THROUGH MONDAY. PERRY
AVIATION...00Z TAFS...LOW STRATUS AND FOG WILL CONTINUE OVER THE
LOWLANDS FOR THE NEXT 24 HOURS. CLOUD LAYER BASE HAS RISEN TO ABOUT
2500 FEET THIS AFTERNOON AND ERODED FROM THE KRDM AREA BUT EXPECT
THE CLOUD DECK TO LOWER AND EXPAND BACK TO KRDM AFTER SUNDOWN.
TOMORROW AFTERNOON WILL SEE A SIMILAR RISE IN THE CLOUD BASES AND AN
EROSION AGAIN AROUND THE EDGES IN CENTRAL OREGON WITH KRDM LIKELY TO
CLEAR FOR A TIME. CLOUD TOPS WILL REMAIN AT AROUND 4000 TO 4500
FEET. AWAY FROM THE STRATUS LAYER...SKIES WILL REMAIN CLEAR ASIDE
FROM SCATTERED CIRRUS ABOVE 20K FEET AGL. WINDS WILL REMAIN UNDER 10
KTS FOR THE NEXT 24 HOURS. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 27 31 25 35 / 0 0 0 10
ALW 28 33 26 33 / 0 0 0 10
PSC 29 36 27 33 / 0 0 0 10
YKM 26 33 23 36 / 0 0 0 10
HRI 28 33 26 34 / 0 0 0 10
ELN 26 32 21 37 / 0 0 0 10
RDM 22 38 20 45 / 0 0 0 10
LGD 23 36 21 40 / 0 0 0 10
GCD 21 38 20 45 / 0 0 0 10
DLS 30 36 28 37 / 0 0 0 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
94/
000
FXUS66 KPDT 192337 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
337 PM PST MON JAN 19 2009
UPDATED AVIATION DISCUSSION.
.SHORT TERM...TONIGHT THROUGH THURSDAY...AN UPPER LEVEL RIDGE WILL
DRIFT SLOWLY EAST TONIGHT THROUGH WEDNESDAY. THIS WILL KEEP STRONG
SURFACE INVERSIONS IN THE LOWER COLUMBIA BASIN AND ADJACENT
VALLEYS...WITH GENERALLY LIGHT WINDS OVER ALL OF EASTERN WASHINGTON
AND OREGON. DIURNAL TEMPERATURE RANGES WILL REMAIN SMALL IN THE
AREAS OF LOW CLOUDS AND FOG. THE AREA OF LOW CLOUDS AND FOG WILL
SLOWLY CONTRACT IN SIZE AS WARM SOUTHERLY FLOW STRENGTHENS THE TOP
OF THE SURFACE INVERSIONS AND LOWERS THE THICKER FREEZING FOG AGAIN.
THIS WILL ALLOW CENTRAL OREGON AND AREAS ABOVE 2500 FEET IN NORTH
CENTRAL OREGON TO BREAK OUT OF THE FOG AND LOW STRATUS TOMORROW
AFTERNOON AND HAVE WARMER HIGH TEMPERATURES...WHILE LOWER ELEVATIONS
WILL SEE MORE THICKER FOG REDUCING VISIBILITY. WEDNESDAY NIGHT AND
THURSDAY A CUTOFF LOW IN CALIFORNIA WILL UNCUT THE WEAKENING
RIDGE...AND MAY TRIGGER A FEW SHOWERS IN THE OREGON MOUNTAINS WHERE
OROGRAPHIC LIFTING WILL ENHANCE INSTABILITY ASSOCIATED WITH THE LOW.
THE MODELS DO NOT SHOW ENOUGH WIND TO BREAK UP THE LOW LEVEL
INVERSIONS EXCEPT IN CENTRAL OREGON AND JOHN DAY VALLEY...BUT THE
INVERSIONS WILL BECOME WEAKER WITH COLDER AIR ALOFT. WILL EXTEND THE
CURRENT AIR STAGNATION ADVISORY SHORTLY UNTIL THURSDAY AFTERNOON TO
COVER THIS CONTINUING SITUATION. COONFIELD
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...MODELS ARE COMING INTO
BETTER AGREEMENT DURING THE LONG TERM PERIOD. BOTH THE GFS AND ECMWF
BRING AN UPPER LOW SOUTH ALONG THE PACIFIC NORTHWEST COAST THURSDAY
NIGHT THROUGH FRIDAY NIGHT. CIRCULATION AROUND THE LOW BUILDS SOME
MILD RIDGING OVER THE AREA. THE LOW DOES NOT SEND AN ORGANIZED FRONT
THROUGH THE AREA. THE SITUATION DOES NOT LOOK STRONG ENOUGH TO ME TO
SCOUR OUT THE COLD AIR IN THE COLUMBIA BASIN SO HAVE HELD ONTO THE
LOW CLOUDS AND FOG THROUGH THIS PERIOD. HAVE THEREFORE KEPT
TEMPERATURES IN THE COLUMBIA BASIN AND ADJACENT LOWLANDS IN A NARROW
RANGE FROM THE MID 20S TO MID 30S. HOWEVER...THE SITUATION IS FAIRLY
TRICKY AND CONFIDENCE IN THE CONTINUATION OF THE LOW CLOUDS AND FOG
IS NOT HIGH AFTER THURSDAY NIGHT. ELSEWHERE IN THE AREA...THE
RIDGING SHOULD WARM TEMPERATURES SO HAVE NUDGED THEM UP A BIT INTO
THE LOWER 40S FOR THE BEND AREA. BOTH MODELS SEND SOME PRECIPITATION
INTO THE SOUTHERN HALF OF THE AREA FRIDAY AND FRIDAY NIGHT SO HAVE
SOME RAIN AND SNOW SHOWERS MAINLY IN THE MOUNTAINS AND EXPANDED IT
OUT OF THE MOUNTAINS ON SATURDAY. BY SATURDAY NIGHT THE LOW HAS
MOVED SOUTH OUT OF THE AREA AND A TROUGH MOVES IN WITH A COOL NORTH
TO NORTHWEST FLOW THROUGH MONDAY. MODELS DIFFER AS THE NATURE OF THE
TROUGH. THE ECMWF HAS A MORE NORTHWESTERLY FLOW OFF THE PACIFIC
WHILE THE GFS IS MORE NORTHERLY AND STILL TRYING TO WORK SOME ARCTIC
AIR IN OUT OF CANADA BUT TO A LESSER DEGREE THAN EARLIER RUNS. HAVE
SIDED WITH THE ECMWF BUT COOLED TEMPS A BIT TOWARDS THE GFS. WITH
THE TROUGH IN PLACE A SERIES OF DISTURBANCE WILL BRING A CHANCE OF
SNOW TO THE MOUNTAINS AND A SLIGHT CHANCE OF RAIN AND SNOW SATURDAY
NIGHT THROUGH MONDAY. PERRY
&&
.AVIATION...00Z TAFS...LOW STRATUS AND FOG WILL CONTINUE OVER THE
LOWLANDS FOR THE NEXT 24 HOURS. CLOUD LAYER BASE HAS RISEN TO ABOUT
2500 FEET THIS AFTERNOON AND ERODED FROM THE KRDM AREA BUT EXPECT
THE CLOUD DECK TO LOWER AND EXPAND BACK TO KRDM AFTER SUNDOWN.
TOMORROW AFTERNOON WILL SEE A SIMILAR RISE IN THE CLOUD BASES AND AN
EROSION AGAIN AROUND THE EDGES IN CENTRAL OREGON WITH KRDM LIKELY TO
CLEAR FOR A TIME. CLOUD TOPS WILL REMAIN AT AROUND 4000 TO 4500
FEET. AWAY FROM THE STRATUS LAYER...SKIES WILL REMAIN CLEAR ASIDE
FROM SCATTERED CIRRUS ABOVE 20K FEET AGL. WINDS WILL REMAIN UNDER 10
KTS FOR THE NEXT 24 HOURS. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 27 31 25 35 / 0 0 0 10
ALW 28 33 26 33 / 0 0 0 10
PSC 29 36 27 33 / 0 0 0 10
YKM 25 33 23 36 / 0 0 0 10
HRI 28 33 26 34 / 0 0 0 10
ELN 26 32 21 37 / 0 0 0 10
RDM 23 39 20 45 / 0 0 0 10
LGD 24 36 21 40 / 0 0 0 10
GCD 23 38 20 45 / 0 0 0 10
DLS 30 36 28 37 / 0 0 0 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
76/83/83
000
FXUS66 KPDT 192205
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
205 PM PST MON JAN 19 2009
.SHORT TERM...TONIGHT THROUGH THURSDAY...AN UPPER LEVEL RIDGE WILL
DRIFT SLOWLY EAST TONIGHT THROUGH WEDNESDAY. THIS WILL KEEP STRONG
SURFACE INVERSIONS IN THE LOWER COLUMBIA BASIN AND ADJACENT
VALLEYS...WITH GENERALLY LIGHT WINDS OVER ALL OF EASTERN WASHINGTON
AND OREGON. DIURNAL TEMPERATURE RANGES WILL REMAIN SMALL IN THE
AREAS OF LOW CLOUDS AND FOG. THE AREA OF LOW CLOUDS AND FOG WILL
SLOWLY CONTRACT IN SIZE AS WARM SOUTHERLY FLOW STRENGTHENS THE TOP
OF THE SURFACE INVERSIONS AND LOWERS THE THICKER FREEZING FOG AGAIN.
THIS WILL ALLOW CENTRAL OREGON AND AREAS ABOVE 2500 FEET IN NORTH
CENTRAL OREGON TO BREAK OUT OF THE FOG AND LOW STRATUS TOMORROW
AFTERNOON AND HAVE WARMER HIGH TEMPERATURES...WHILE LOWER ELEVATIONS
WILL SEE MORE THICKER FOG REDUCING VISIBILITY. WEDNESDAY NIGHT AND
THURSDAY A CUTOFF LOW IN CALIFORNIA WILL UNCUT THE WEAKENING
RIDGE...AND MAY TRIGGER A FEW SHOWERS IN THE OREGON MOUNTAINS WHERE
OROGRAPHIC LIFTING WILL ENHANCE INSTABILITY ASSOCIATED WITH THE LOW.
THE MODELS DO NOT SHOW ENOUGH WIND TO BREAK UP THE LOW LEVEL
INVERSIONS EXCEPT IN CENTRAL OREGON AND JOHN DAY VALLEY...BUT THE
INVERSIONS WILL BECOME WEAKER WITH COLDER AIR ALOFT. WILL EXTEND THE
CURRENT AIR STAGNATION ADVISORY SHORTLY UNTIL THURSDAY AFTERNOON TO
COVER THIS CONTINUING SITUATION. COONFIELD
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...MODELS ARE COMING INTO
BETTER AGREEMENT DURING THE LONG TERM PERIOD. BOTH THE GFS AND ECMWF
BRING AN UPPER LOW SOUTH ALONG THE PACIFIC NORTHWEST COAST THURSDAY
NIGHT THROUGH FRIDAY NIGHT. CIRCULATION AROUND THE LOW BUILDS SOME
MILD RIDGING OVER THE AREA. THE LOW DOES NOT SEND AN ORGANIZED FRONT
THROUGH THE AREA. THE SITUATION DOES NOT LOOK STRONG ENOUGH TO ME TO
SCOUR OUT THE COLD AIR IN THE COLUMBIA BASIN SO HAVE HELD ONTO THE
LOW CLOUDS AND FOG THROUGH THIS PERIOD. HAVE THEREFORE KEPT
TEMPERATURES IN THE COLUMBIA BASIN AND ADJACENT LOWLANDS IN A NARROW
RANGE FROM THE MID 20S TO MID 30S. HOWEVER...THE SITUATION IS FAIRLY
TRICKY AND CONFIDENCE IN THE CONTINUATION OF THE LOW CLOUDS AND FOG
IS NOT HIGH AFTER THURSDAY NIGHT. ELSEWHERE IN THE AREA...THE
RIDGING SHOULD WARM TEMPERATURES SO HAVE NUDGED THEM UP A BIT INTO
THE LOWER 40S FOR THE BEND AREA. BOTH MODELS SEND SOME PRECIPITATION
INTO THE SOUTHERN HALF OF THE AREA FRIDAY AND FRIDAY NIGHT SO HAVE
SOME RAIN AND SNOW SHOWERS MAINLY IN THE MOUNTAINS AND EXPANDED IT
OUT OF THE MOUNTAINS ON SATURDAY. BY SATURDAY NIGHT THE LOW HAS
MOVED SOUTH OUT OF THE AREA AND A TROUGH MOVES IN WITH A COOL NORTH
TO NORTHWEST FLOW THROUGH MONDAY. MODELS DIFFER AS THE NATURE OF THE
TROUGH. THE ECMWF HAS A MORE NORTHWESTERLY FLOW OFF THE PACIFIC
WHILE THE GFS IS MORE NORTHERLY AND STILL TRYING TO WORK SOME ARCTIC
AIR IN OUT OF CANADA BUT TO A LESSER DEGREE THAN EARLIER RUNS. HAVE
SIDED WITH THE ECMWF BUT COOLED TEMPS A BIT TOWARDS THE GFS. WITH
THE TROUGH IN PLACE A SERIES OF DISTURBANCE WILL BRING A CHANCE OF
SNOW TO THE MOUNTAINS AND A SLIGHT CHANCE OF RAIN AND SNOW SATURDAY
NIGHT THROUGH MONDAY. PERRY
&&
.AVIATION...18Z TAFS...LOW STRATUS AND FOG WILL CONTINUE OVER THE
AREA FOR THE NEXT 24 HOURS. CLOUD BASES ARE BETWEEN 1700 AND 2500
FEET MSL AND TOPS ARE BETWEEN 4000 AND 4500 FEET MSL. FOG WILL BE
CONFINED TO THE CLOUD LAYER WITH LOW STRATUS BENEATH THAT LEVEL AND
ONLY SOME HIGH THIN CIRRUS ABOVE THE LAYER. WEAK SUBSIDENCE
OVERNIGHT AND TOMORROW MORNING MAY PUSH THE CLOUD LAYER DOWNWARD A
FEW HUNDRED FEET BUT DO NOT ANTICIPATE REDUCED VISIBILITY OR FOG AT
ANY TAF LOCATION. WINDS WILL REMAIN LIGHT AND VARIABLE AND GENERALLY
UNDER 10 KTS. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 27 31 25 35 / 0 0 0 10
ALW 28 33 26 33 / 0 0 0 10
PSC 29 36 27 33 / 0 0 0 10
YKM 25 33 23 36 / 0 0 0 10
HRI 28 33 26 34 / 0 0 0 10
ELN 26 32 21 37 / 0 0 0 10
RDM 23 39 20 45 / 0 0 0 10
LGD 24 36 21 40 / 0 0 0 10
GCD 23 38 20 45 / 0 0 0 10
DLS 30 36 28 37 / 0 0 0 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
76/83/83
000
FXUS66 KPDT 191751 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
950 AM PST MON JAN 19 2009
UPDATED AVIATION DISCUSSION.
.UPDATE...UPPER LEVEL RIDGE WILL PERSIST OVER THE PACIFIC
NORTHWEST WITH LOW CLOUDS AND FOG IN THE LOWER COLUMBIA BASIN AND
ADJACENT VALLEYS. WINDS REMAIN LIGHT AS WELL. FORECAST ON TRACK.
COONFIELD
&&
.AVIATION...18Z TAFS...LOW STRATUS AND FOG WILL CONTINUE OVER THE
AREA FOR THE NEXT 24 HOURS. CLOUD BASES ARE BETWEEN 1700 AND 2500
FEET MSL AND TOPS ARE BETWEEN 4000 AND 4500 FEET MSL. FOG WILL BE
CONFINED TO THE CLOUD LAYER WITH LOW STRATUS BENEATH THAT LEVEL AND
ONLY SOME HIGH THIN CIRRUS ABOVE THE LAYER. WEAK SUBSIDENCE
OVERNIGHT AND TOMORROW MORNING MAY PUSH THE CLOUD LAYER DOWNWARD A
FEW HUNDRED FEET BUT DO NOT ANTICIPATE REDUCED VISIBILITY OR FOG AT
ANY TAF LOCATION. WINDS WILL REMAIN LIGHT AND VARIABLE AND GENERALLY
UNDER 10 KTS. PERRY
&&
.PREV DISCUSSION... /ISSUED 255 AM PST MON JAN 19 2009/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST AND IT/S STRENGTH WILL WEAKEN. THE AREA
OF FOG AND STATUS OVER THE INTERIOR NORTHWEST HAS GENERALLY REACHED
IT/S MAXIMUM DEPTH AND AREAL COVERAGE. TOPS OF THIS FOG/STRATUS AREA
ARE STILL ROUGHLY BETWEEN 4000 AND 4500 FEET MSL. STRATUS BASES ALSO
REMAIN ROUGHLY BETWEEN 1800 FEET TO 2600 FEET MSL...AND MOST THREATS
OF THICK FREEZING FOG ARE STILL MAINLY ABOVE 1900 FEET MSL. AS SUCH
WILL CONTINUE ALL CURRENT ADVISORIES. SHOULD SEE SOME BURN OFF
AROUND THE FRINGES OF THE FOG/STRATUS MASS AGAIN THIS AFTERNOON.
HIGH TEMPS SHOULD GENERALLY BE SIMILAR TO YESTERDAY...PLUS/MINUS A
DEGREE OR TWO. THE UPPER RIDGE AXIS WILL SHIFT TO A POSITION OVER
THE GREAT BASIN NORTH TO WESTERN MONTANA TONIGHT. THIS SHOULD RESULT
IN A SOUTH FLOW ALOFT OVER THE PACNW. THIS FLOW SHOULD BEGIN TO PUT
INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA. THIS DOWNWARD
FORCE WILL RESULT IN THE TOPS GRADUALLY LOWERING AND THE AREAL
COVERAGE SHRINKING TUESDAY AND TUESDAY NIGHT. THIS SHOULD ALSO BEGIN
THE PROCESS OF PUSHING THE THICKER FREEZING FOG AREAS BACK TO LOWER
ELEVATIONS. 90
LONG TERM...WEDNESDAY THROUGH SUNDAY...SOME BIG CHANGES ARE
FORECAST BY THE LONG RANGE PROGS...ESPECIALLY THE GFS. THESE MODELS
ARE IN FAIRLY GOOD AGREEMENT THROUGH WEDNESDAY NIGHT. AFTER THAT
THEY DEVELOP SOME MAJOR DIFFERENCES...ESPECIALLY BETWEEN THE GFS VS
THE ECMWF. THE STRONG UPPER RIDGE THAT HAS BEEN OVER THE REGION WILL
PERSIST THROUGH WEDNESDAY NIGHT OR POSSIBLY THURSDAY WITH A
CONTINUATION OF MILD AND DRY CONDITIONS IN THE HIGHER ELEVATIONS AND
WIDESPREAD STRATUS WITH PATCHY FOG IN THE VALLEYS/COLUMBIA BASIN.
THIS WILL CONTINUE TO KEEP BELOW NORMAL TEMPERATURES IN THE
VALLEYS/COLUMBIA BASIN. BY THURSDAY AFTERNOON THE GFS BREAKS A PIECE
OF ENERGY OFF FROM THE NORTHERN JET STREAM AND DIVES IT DOWN THE
COAST FOR AN ARCTIC PUSH INTO THE PACIFIC NW. THE ECMWF KEEPS A
CLOSED LOW WELL OFF THE CALIFORNIA COAST WITH A SPLIT W-SW FLOW OVER
THE CWA. THESE TWO DIFFERENT SOLUTIONS WILL MEAN THE DIFFERENCE
BETWEEN AN ARCTIC INTRUSION INTO THE REGION WITH MAINLY LIGHT
SNOW...OR A SLOW BREAK DOWN OF THE UPPER RIDGE CURRENTLY HOLDING
STRONG. WITH RECENT MAJOR DIFFERENCES IN THESE PROGS AND THE
PERSISTENCE OF THE UPPER RIDGE AM LEANING TOWARD THE WARMER AND
CALMER ECMWF SOLUTION. HOWEVER DO NOT WANT TO DISCOUNT THE GFS
COMPLETELY SO WILL NUDGE THE FORECAST TOWARD THE GFS AND SHOW A BIT
MORE COOLING AND SOME LIGHT SNOW IN THE LATTER PART OF THE EXTENDED
PERIOD. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 31 27 30 26 / 0 0 0 0
ALW 33 29 32 28 / 0 0 0 0
PSC 36 31 35 30 / 0 0 0 0
YKM 33 28 32 27 / 0 0 0 0
HRI 33 30 32 29 / 0 0 0 0
ELN 31 27 31 26 / 0 0 0 0
RDM 27 23 28 23 / 0 0 0 0
LGD 35 24 35 23 / 0 0 0 0
GCD 30 22 32 22 / 0 0 0 0
DLS 36 32 35 31 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
76/83/83
000
FXUS66 KPDT 191058
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
255 AM PST MON JAN 19 2009
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST AND IT/S STRENGTH WILL WEAKEN. THE AREA
OF FOG AND STATUS OVER THE INTERIOR NORTHWEST HAS GENERALLY REACHED
IT/S MAXIMUM DEPTH AND AREAL COVERAGE. TOPS OF THIS FOG/STRATUS AREA
ARE STILL ROUGHLY BETWEEN 4000 AND 4500 FEET MSL. STRATUS BASES ALSO
REMAIN ROUGHLY BETWEEN 1800 FEET TO 2600 FEET MSL...AND MOST THREATS
OF THICK FREEZING FOG ARE STILL MAINLY ABOVE 1900 FEET MSL. AS SUCH
WILL CONTINUE ALL CURRENT ADVISORIES. SHOULD SEE SOME BURN OFF
AROUND THE FRINGES OF THE FOG/STRATUS MASS AGAIN THIS AFTERNOON.
HIGH TEMPS SHOULD GENERALLY BE SIMILAR TO YESTERDAY...PLUS/MINUS A
DEGREE OR TWO. THE UPPER RIDGE AXIS WILL SHIFT TO A POSITION OVER
THE GREAT BASIN NORTH TO WESTERN MONTANA TONIGHT. THIS SHOULD RESULT
IN A SOUTH FLOW ALOFT OVER THE PACNW. THIS FLOW SHOULD BEGIN TO PUT
INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA. THIS DOWNWARD
FORCE WILL RESULT IN THE TOPS GRADUALLY LOWERING AND THE AREAL
COVERAGE SHRINKING TUESDAY AND TUESDAY NIGHT. THIS SHOULD ALSO BEGIN
THE PROCESS OF PUSHING THE THICKER FREEZING FOG AREAS BACK TO LOWER
ELEVATIONS. 90
.LONG TERM...WEDNESDAY THROUGH SUNDAY...SOME BIG CHANGES ARE
FORECAST BY THE LONG RANGE PROGS...ESPECIALLY THE GFS. THESE MODELS
ARE IN FAIRLY GOOD AGREEMENT THROUGH WEDNESDAY NIGHT. AFTER THAT
THEY DEVELOP SOME MAJOR DIFFERENCES...ESPECIALLY BETWEEN THE GFS VS
THE ECMWF. THE STRONG UPPER RIDGE THAT HAS BEEN OVER THE REGION WILL
PERSIST THROUGH WEDNESDAY NIGHT OR POSSIBLY THURSDAY WITH A
CONTINUATION OF MILD AND DRY CONDITIONS IN THE HIGHER ELEVATIONS AND
WIDESPREAD STRATUS WITH PATCHY FOG IN THE VALLEYS/COLUMBIA BASIN.
THIS WILL CONTINUE TO KEEP BELOW NORMAL TEMPERATURES IN THE
VALLEYS/COLUMBIA BASIN. BY THURSDAY AFTERNOON THE GFS BREAKS A PIECE
OF ENERGY OFF FROM THE NORTHERN JET STREAM AND DIVES IT DOWN THE
COAST FOR AN ARCTIC PUSH INTO THE PACIFIC NW. THE ECMWF KEEPS A
CLOSED LOW WELL OFF THE CALIFORNIA COAST WITH A SPLIT W-SW FLOW OVER
THE CWA. THESE TWO DIFFERENT SOLUTIONS WILL MEAN THE DIFFERENCE
BETWEEN AN ARCTIC INTRUSION INTO THE REGION WITH MAINLY LIGHT
SNOW...OR A SLOW BREAK DOWN OF THE UPPER RIDGE CURRENTLY HOLDING
STRONG. WITH RECENT MAJOR DIFFERENCES IN THESE PROGS AND THE
PERSISTENCE OF THE UPPER RIDGE AM LEANING TOWARD THE WARMER AND
CALMER ECMWF SOLUTION. HOWEVER DO NOT WANT TO DISCOUNT THE GFS
COMPLETELY SO WILL NUDGE THE FORECAST TOWARD THE GFS AND SHOW A BIT
MORE COOLING AND SOME LIGHT SNOW IN THE LATTER PART OF THE EXTENDED
PERIOD. 88
&&
.AVIATION...LOW STRATUS WITH PATCHY FOG WILL PERSIST TODAY...
ESPECIALLY AT KRDM...KYKM AND KALW WHERE THE CEILING WILL BE NEAREST
TO THE SURFACE. THERE WILL BE PERIODS OF MVFR/IFR CONDITIONS WITH
VISIBILITY BELOW 1SM AND CEILINGS AS LOW AS 500 FT AGL THROUGH
TONIGHT. WINDS WILL REMAIN LIGHT AND GENERALLY UNDER 10 KTS. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 31 27 30 26 / 0 0 0 0
ALW 33 29 32 28 / 0 0 0 0
PSC 36 31 35 30 / 0 0 0 0
YKM 33 28 32 27 / 0 0 0 0
HRI 33 30 32 29 / 0 0 0 0
ELN 31 27 31 26 / 0 0 0 0
RDM 27 23 28 23 / 0 0 0 0
LGD 35 24 35 23 / 0 0 0 0
GCD 30 22 32 22 / 0 0 0 0
DLS 36 32 35 31 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
90/88/88
000
FXUS66 KPDT 190516 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
920 PM PST SUN JAN 18 2009
UPDATED AVIATION DISCUSSION
.UPDATE...NO MAJOR CHANGES MADE. UPDATED TONIGHTS LOW TEMPERATURES
BASED ON CURRENT OBSERVATIONS AND TRENDS. LOW STRATUS AND FOG WILL
PERSIST THROUGH THE NIGHT IN THE LOWER ELEVATIONS. THERE IS EVEN A
SMALL CHANCE FOR OCCASIONAL LIGHT SNOW OR FREEZING DRIZZLE IN THESE
AREAS. SNOW HAS BEEN OBSERVED AT THE PASCO AIRPORT...BUT
ACCUMULATION IS NOT LIKELY. CALDER
&&
.AVIATION...06Z TAFS...HIGH PRESSURE CONTINUES TO DOMINATE LOCAL
CONDITIONS AND LOW CLOUDS AND FOG WILL REMAIN OVER MUCH OF THE AREA
FOR THE NEXT 24 HOURS. THE LOW CEILINGS WILL CAUSE MVFR
CONDITIONS...WITH IFR CONDITIONS LIKELY AT KALW...KPDT AND KRDM. AS
SUBSIDENCE CAUSES THE STRATUS LAYER TO COMPRESS AND LOWER OVERNIGHT
AND INTO MONDAY MORNING...KALW AND KRDM WILL EXPERIENCE VISIBILITIES
LESS THAN 6SM. WINDS WILL REMAIN BELOW 10 KTS AT ALL TAF LOCATIONS.
82
&&
.PREV DISCUSSION... /ISSUED 341 PM PST SUN JAN 18 2009/
SHORT TERM...TONIGHT THROUGH WEDNESDAY...NO MAJOR CHANGES MADE AS
THE FOG AND STRATUS LAYER REMAINS SOMEWHAT NEBULOUS. INVERSION AND
SUBSIDENCE STRENGTHENS TONIGHT AND EXPECT THE TOP OF THE LAYER TO
DROP A BIT BRINGING TOPS TO AROUND 3500 TO 4000 FEET. AS SUCH, WILL
LET GO OF THE FREEZING FOG ADVISORY ACROSS THE NORTHERN BLUE
MOUNTAINS AS IT NO LONGER APPEAR A SIGNIFICANT STRETCH OF I-84 WILL
BE AFFECTED UP TOP. CABBAGE HILL WILL STILL REMAIN IN THE MIDST OF
THE DECK. HAVE EXTENDED THE REMAINING FREEZING FOG ADVISORIES INTO
DIFFERING PORTIONS OF TUESDAY AS NOT MUCH CHANGE IS EXPECTED UNTIL
PERHAPS TUESDAY AFTERNOON. IT`S MORE LIKELY THE FOG/STRATUS WILL
LEAVE THE AREA COMPLETELY LATER IN THE WEEK VERSUS EARLIER, BUT DID
NOT HAVE SPECIFIC LOCATION AND INVERSION TOP/LAYER THICKNESS
CONFIDENCE TO JUSTIFY A FURTHER EXTENSION. WINDS REMAIN LIGHT WITH
TEMPERATURES COOL UNDER THE DECK ALONG WITH MORE SUNNY DAYS AND
WARMER TEMPERATURES ABOVE THE STRATUS DECK. /JBONK
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS ARE COMING INTO
BETTER AGREEMENT IN THE LONG TERM PERIOD. BOTH OF THE LATEST GFS AND
ECMWF RUNS BRING A SPLITTING TROUGH INTO THE WEST COAST WEDNESDAY
NIGHT WITH THE MAIN ENERGY GOING TO THE NORTH AND SOUTH OF US. HAVE
KEPT THE FORECAST DRY WEDNESDAY NIGHT AND ADDED A FEW MOUNTAIN
SHOWERS THURSDAY. ALSO KEPT THE LOW CLOUDS AND FOG IN THE COLUMBIA
BASIN AND ADJACENT VALLEYS AS THIS SYSTEM DOES NOT LOOK STRONG
ENOUGH TO MIX OUT THE INVERSION. AFTER THIS POINT...THE ECMWF THIS
MAKES A SIGNIFICANT DEPARTURE FROM PREVIOUS RUNS AND TRENDED
TOWARDS THE GFS SOLUTION. AM HESITANT TO JUMP FULLY INTO THIS
SOLUTION AS THE GFS HAD BEEN CONSIDERED AN OUTLIER SOLUTION AND WILL
AWAIT THE NEXT ECMWF RUNS TO SEE IF THIS CHANGE IS MAINTAINED. THAT
BEING SAID...THE FLOW LOOKS PRETTY WEAK AND DISORGANIZED THURSDAY
NIGHT THROUGH FRIDAY NIGHT WITH THE GFS AND ECMWF STILL HANDLING IT
SOMEWHAT DIFFERENTLY. HAVE GRADUALLY INCREASED THE POPS AND KEPT THE
LOW CLOUDS AND FOG. THE GFS IS WETTER AND WOULD MIX OUT THE CLOUDS
AND FOG WHILE THE ECMWF IS DRIER AND LIKELY TO CONTINUE THE CLOUDS
AND FOG. HAVE TENDED TOWARDS THE ECMWF BY KEEPING LOW CLOUDS AND FOG
BUT ALSO GRADUALLY INCREASED POPS. BOTH THE ECMWF AND GFS BRING A
STRONG TROUGH INTO THE AREA SATURDAY AND THIS WILL FINALLY MIX OUT
THE CLOUDS AND FOG ONCE AND FOR ALL IF IT HAS NOT ALREADY HAPPENED.
IT WILL ALSO BRING A CHANCE OF SNOW TO THE MOUNTAINS AND A SLIGHT
CHANCE OF RAIN AND SNOW TO THE LOWLANDS SATURDAY THROUGH SUNDAY. THE
GFS SOLUTION BRINGS COLD AIR IN OUT OF CANADA AND LOOKS COLD WHILE
THE ECMWF BRINGS THIS SYSTEM OUT OF THE GULF OF ALASKA AND IS NOT AS
COLD. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 28 29 27 29 / 10 0 0 0
ALW 28 31 29 31 / 10 0 0 0
PSC 30 34 28 34 / 10 0 0 0
YKM 28 32 25 32 / 10 0 0 0
HRI 30 32 27 32 / 10 0 0 0
ELN 28 31 26 31 / 10 0 0 0
RDM 22 27 24 30 / 10 0 0 0
LGD 21 32 26 32 / 10 0 0 0
GCD 18 33 24 33 / 10 0 0 0
DLS 33 34 30 34 / 10 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
82/
000
FXUS66 KPDT 190407
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
805 PM PST SUN JAN 18 2009
.UPDATE...NO MAJOR CHANGES MADE. UPDATED TONIGHTS LOW TEMPERATURES
BASED ON CURRENT OBSERVATIONS AND TRENDS. LOW STRATUS AND FOG WILL
PERSIST THROUGH THE NIGHT IN THE LOWER ELEVATIONS. THERE IS EVEN A
SMALL CHANCE FOR OCCASIONAL LIGHT SNOW OR FREEZING DRIZZLE IN THESE
AREAS. SNOW HAS BEEN OBSERVED AT THE PASCO AIRPORT...BUT
ACCUMULATION IS NOT LIKELY. CALDER
&&
.PREV DISCUSSION... /ISSUED 341 PM PST SUN JAN 18 2009/
SHORT TERM...TONIGHT THROUGH WEDNESDAY...NO MAJOR CHANGES MADE AS
THE FOG AND STRATUS LAYER REMAINS SOMEWHAT NEBULOUS. INVERSION AND
SUBSIDENCE STRENGTHENS TONIGHT AND EXPECT THE TOP OF THE LAYER TO
DROP A BIT BRINGING TOPS TO AROUND 3500 TO 4000 FEET. AS SUCH, WILL
LET GO OF THE FREEZING FOG ADVISORY ACROSS THE NORTHERN BLUE
MOUNTAINS AS IT NO LONGER APPEAR A SIGNIFICANT STRETCH OF I-84 WILL
BE AFFECTED UP TOP. CABBAGE HILL WILL STILL REMAIN IN THE MIDST OF
THE DECK. HAVE EXTENDED THE REMAINING FREEZING FOG ADVISORIES INTO
DIFFERING PORTIONS OF TUESDAY AS NOT MUCH CHANGE IS EXPECTED UNTIL
PERHAPS TUESDAY AFTERNOON. IT`S MORE LIKELY THE FOG/STRATUS WILL
LEAVE THE AREA COMPLETELY LATER IN THE WEEK VERSUS EARLIER, BUT DID
NOT HAVE SPECIFIC LOCATION AND INVERSION TOP/LAYER THICKNESS
CONFIDENCE TO JUSTIFY A FURTHER EXTENSION. WINDS REMAIN LIGHT WITH
TEMPERATURES COOL UNDER THE DECK ALONG WITH MORE SUNNY DAYS AND
WARMER TEMPERATURES ABOVE THE STRATUS DECK. /JBONK
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS ARE COMING INTO
BETTER AGREEMENT IN THE LONG TERM PERIOD. BOTH OF THE LATEST GFS AND
ECMWF RUNS BRING A SPLITTING TROUGH INTO THE WEST COAST WEDNESDAY
NIGHT WITH THE MAIN ENERGY GOING TO THE NORTH AND SOUTH OF US. HAVE
KEPT THE FORECAST DRY WEDNESDAY NIGHT AND ADDED A FEW MOUNTAIN
SHOWERS THURSDAY. ALSO KEPT THE LOW CLOUDS AND FOG IN THE COLUMBIA
BASIN AND ADJACENT VALLEYS AS THIS SYSTEM DOES NOT LOOK STRONG
ENOUGH TO MIX OUT THE INVERSION. AFTER THIS POINT...THE ECMWF THIS
MAKES A SIGNIFICANT DEPARTURE FROM PREVIOUS RUNS AND TRENDED
TOWARDS THE GFS SOLUTION. AM HESITANT TO JUMP FULLY INTO THIS
SOLUTION AS THE GFS HAD BEEN CONSIDERED AN OUTLIER SOLUTION AND WILL
AWAIT THE NEXT ECMWF RUNS TO SEE IF THIS CHANGE IS MAINTAINED. THAT
BEING SAID...THE FLOW LOOKS PRETTY WEAK AND DISORGANIZED THURSDAY
NIGHT THROUGH FRIDAY NIGHT WITH THE GFS AND ECMWF STILL HANDLING IT
SOMEWHAT DIFFERENTLY. HAVE GRADUALLY INCREASED THE POPS AND KEPT THE
LOW CLOUDS AND FOG. THE GFS IS WETTER AND WOULD MIX OUT THE CLOUDS
AND FOG WHILE THE ECMWF IS DRIER AND LIKELY TO CONTINUE THE CLOUDS
AND FOG. HAVE TENDED TOWARDS THE ECMWF BY KEEPING LOW CLOUDS AND FOG
BUT ALSO GRADUALLY INCREASED POPS. BOTH THE ECMWF AND GFS BRING A
STRONG TROUGH INTO THE AREA SATURDAY AND THIS WILL FINALLY MIX OUT
THE CLOUDS AND FOG ONCE AND FOR ALL IF IT HAS NOT ALREADY HAPPENED.
IT WILL ALSO BRING A CHANCE OF SNOW TO THE MOUNTAINS AND A SLIGHT
CHANCE OF RAIN AND SNOW TO THE LOWLANDS SATURDAY THROUGH SUNDAY. THE
GFS SOLUTION BRINGS COLD AIR IN OUT OF CANADA AND LOOKS COLD WHILE
THE ECMWF BRINGS THIS SYSTEM OUT OF THE GULF OF ALASKA AND IS NOT AS
COLD. PERRY
AVIATION...00Z TAFS...HIGH PRESSURE CONTINUES TO DOMINATE LOCAL
CONDITIONS AND LOW CLOUDS AND FOG WILL REMAIN OVER MUCH OF THE AREA
FOR THE NEXT 24 HOURS. CEILINGS WILL GENERALLY BE AT 1500 TO 2500
FEET AGL WITH TOPS AT 4000 TO 4500 FEET THROUGH THIS EVENING WHEN
SUBSIDENCE WILL BEGIN LOWERING THE STRATUS DECK. KRDM WILL BE AN
EXCEPTION WITH CEILINGS REMAINING BELOW 500 TO 700 FEET AGL AND
VISIBILITIES DROPPING TO 3 SM AT TIMES OVERNIGHT AND TOMORROW
MORNING. THE LOWERING STRATUS DECK WILL ALSO BRING VISIBILITIES DOWN
TO 3 TO 5 SM AT KALW LATE TONIGHT AND TOMORROW MORNING. BRIEF SNOW
SHOWERS ARE POSSIBLE AS WELL WHICH WILL LOWER VISIBILITIES TO 1 SM
AT TIMES. ABOVE 4500 FEET AGL...ONLY SOME HIGH THIN CIRRUS ABOVE 20K
FEET AGL IS EXPECTED. WINDS WILL REMAIN BELOW 10 KTS AT ALL TAF
LOCATIONS. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 28 29 27 29 / 10 0 0 0
ALW 28 31 29 31 / 10 0 0 0
PSC 30 34 28 34 / 10 0 0 0
YKM 28 32 25 32 / 10 0 0 0
HRI 30 32 27 32 / 10 0 0 0
ELN 28 31 26 31 / 10 0 0 0
RDM 22 27 24 30 / 10 0 0 0
LGD 21 32 26 32 / 10 0 0 0
GCD 18 33 24 33 / 10 0 0 0
DLS 33 34 30 34 / 10 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
82/
000
FXUS66 KPDT 182341 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
341 PM PST SUN JAN 18 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...NO MAJOR CHANGES MADE AS
THE FOG AND STRATUS LAYER REMAINS SOMEWHAT NEBULOUS. INVERSION AND
SUBSIDENCE STRENGTHENS TONIGHT AND EXPECT THE TOP OF THE LAYER TO
DROP A BIT BRINGING TOPS TO AROUND 3500 TO 4000 FEET. AS SUCH, WILL
LET GO OF THE FREEZING FOG ADVISORY ACROSS THE NORTHERN BLUE
MOUNTAINS AS IT NO LONGER APPEAR A SIGNIFICANT STRETCH OF I-84 WILL
BE AFFECTED UP TOP. CABBAGE HILL WILL STILL REMAIN IN THE MIDST OF
THE DECK. HAVE EXTENDED THE REMAINING FREEZING FOG ADVISORIES INTO
DIFFERING PORTIONS OF TUESDAY AS NOT MUCH CHANGE IS EXPECTED UNTIL
PERHAPS TUESDAY AFTERNOON. IT`S MORE LIKELY THE FOG/STRATUS WILL
LEAVE THE AREA COMPLETELY LATER IN THE WEEK VERSUS EARLIER, BUT DID
NOT HAVE SPECIFIC LOCATION AND INVERSION TOP/LAYER THICKNESS
CONFIDENCE TO JUSTIFY A FURTHER EXTENSION. WINDS REMAIN LIGHT WITH
TEMPERATURES COOL UNDER THE DECK ALONG WITH MORE SUNNY DAYS AND
WARMER TEMPERATURES ABOVE THE STRATUS DECK. /JBONK
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS ARE COMING INTO
BETTER AGREEMENT IN THE LONG TERM PERIOD. BOTH OF THE LATEST GFS AND
ECMWF RUNS BRING A SPLITTING TROUGH INTO THE WEST COAST WEDNESDAY
NIGHT WITH THE MAIN ENERGY GOING TO THE NORTH AND SOUTH OF US. HAVE
KEPT THE FORECAST DRY WEDNESDAY NIGHT AND ADDED A FEW MOUNTAIN
SHOWERS THURSDAY. ALSO KEPT THE LOW CLOUDS AND FOG IN THE COLUMBIA
BASIN AND ADJACENT VALLEYS AS THIS SYSTEM DOES NOT LOOK STRONG
ENOUGH TO MIX OUT THE INVERSION. AFTER THIS POINT...THE ECMWF THIS
MAKES A SIGNIFICANT DEPARTURE FROM PREVIOUS RUNS AND TRENDED
TOWARDS THE GFS SOLUTION. AM HESITANT TO JUMP FULLY INTO THIS
SOLUTION AS THE GFS HAD BEEN CONSIDERED AN OUTLIER SOLUTION AND WILL
AWAIT THE NEXT ECMWF RUNS TO SEE IF THIS CHANGE IS MAINTAINED. THAT
BEING SAID...THE FLOW LOOKS PRETTY WEAK AND DISORGANIZED THURSDAY
NIGHT THROUGH FRIDAY NIGHT WITH THE GFS AND ECMWF STILL HANDLING IT
SOMEWHAT DIFFERENTLY. HAVE GRADUALLY INCREASED THE POPS AND KEPT THE
LOW CLOUDS AND FOG. THE GFS IS WETTER AND WOULD MIX OUT THE CLOUDS
AND FOG WHILE THE ECMWF IS DRIER AND LIKELY TO CONTINUE THE CLOUDS
AND FOG. HAVE TENDED TOWARDS THE ECMWF BY KEEPING LOW CLOUDS AND FOG
BUT ALSO GRADUALLY INCREASED POPS. BOTH THE ECMWF AND GFS BRING A
STRONG TROUGH INTO THE AREA SATURDAY AND THIS WILL FINALLY MIX OUT
THE CLOUDS AND FOG ONCE AND FOR ALL IF IT HAS NOT ALREADY HAPPENED.
IT WILL ALSO BRING A CHANCE OF SNOW TO THE MOUNTAINS AND A SLIGHT
CHANCE OF RAIN AND SNOW TO THE LOWLANDS SATURDAY THROUGH SUNDAY. THE
GFS SOLUTION BRINGS COLD AIR IN OUT OF CANADA AND LOOKS COLD WHILE
THE ECMWF BRINGS THIS SYSTEM OUT OF THE GULF OF ALASKA AND IS NOT AS
COLD. PERRY
&&
.AVIATION...00Z TAFS...HIGH PRESSURE CONTINUES TO DOMINATE LOCAL
CONDITIONS AND LOW CLOUDS AND FOG WILL REMAIN OVER MUCH OF THE AREA
FOR THE NEXT 24 HOURS. CEILINGS WILL GENERALLY BE AT 1500 TO 2500
FEET AGL WITH TOPS AT 4000 TO 4500 FEET THROUGH THIS EVENING WHEN
SUBSIDENCE WILL BEGIN LOWERING THE STRATUS DECK. KRDM WILL BE AN
EXCEPTION WITH CEILINGS REMAINING BELOW 500 TO 700 FEET AGL AND
VISIBILITIES DROPPING TO 3 SM AT TIMES OVERNIGHT AND TOMORROW
MORNING. THE LOWERING STRATUS DECK WILL ALSO BRING VISIBILITIES DOWN
TO 3 TO 5 SM AT KALW LATE TONIGHT AND TOMORROW MORNING. BRIEF SNOW
SHOWERS ARE POSSIBLE AS WELL WHICH WILL LOWER VISIBILITIES TO 1 SM
AT TIMES. ABOVE 4500 FEET AGL...ONLY SOME HIGH THIN CIRRUS ABOVE 20K
FEET AGL IS EXPECTED. WINDS WILL REMAIN BELOW 10 KTS AT ALL TAF
LOCATIONS. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 28 29 27 29 / 10 0 0 0
ALW 30 31 29 31 / 10 0 0 0
PSC 31 34 28 34 / 10 0 0 0
YKM 29 32 25 32 / 10 0 0 0
HRI 30 32 27 32 / 10 0 0 0
ELN 29 31 26 31 / 10 0 0 0
RDM 25 27 24 30 / 10 0 0 0
LGD 25 32 26 32 / 10 0 0 0
GCD 18 33 24 33 / 10 0 0 0
DLS 34 34 30 34 / 10 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87/83/83
000
FXUS66 KPDT 182229
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PST SUN JAN 18 2009
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...NO MAJOR CHANGES MADE AS
THE FOG AND STRATUS LAYER REMAINS SOMEWHAT NEBULOUS. INVERSION AND
SUBSIDENCE STRENGTHENS TONIGHT AND EXPECT THE TOP OF THE LAYER TO
DROP A BIT BRINGING TOPS TO AROUND 3500 TO 4000 FEET. AS SUCH, WILL
LET GO OF THE FREEZING FOG ADVISORY ACROSS THE NORTHERN BLUE
MOUNTAINS AS IT NO LONGER APPEAR A SIGNIFICANT STRETCH OF I-84 WILL
BE AFFECTED UP TOP. CABBAGE HILL WILL STILL REMAIN IN THE MIDST OF
THE DECK. HAVE EXTENDED THE REMAINING FREEZING FOG ADVISORIES INTO
DIFFERING PORTIONS OF TUESDAY AS NOT MUCH CHANGE IS EXPECTED UNTIL
PERHAPS TUESDAY AFTERNOON. IT`S MORE LIKELY THE FOG/STRATUS WILL
LEAVE THE AREA COMPLETELY LATER IN THE WEEK VERSUS EARLIER, BUT DID
NOT HAVE SPECIFIC LOCATION AND INVERSION TOP/LAYER THICKNESS
CONFIDENCE TO JUSTIFY A FURTHER EXTENSION. WINDS REMAIN LIGHT WITH
TEMPERATURES COOL UNDER THE DECK ALONG WITH MORE SUNNY DAYS AND
WARMER TEMPERATURES ABOVE THE STRATUS DECK. /JBONK
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS ARE COMING INTO
BETTER AGREEMENT IN THE LONG TERM PERIOD. BOTH OF THE LATEST GFS AND
ECMWF RUNS BRING A SPLITTING TROUGH INTO THE WEST COAST WEDNESDAY
NIGHT WITH THE MAIN ENERGY GOING TO THE NORTH AND SOUTH OF US. HAVE
KEPT THE FORECAST DRY WEDNESDAY NIGHT AND ADDED A FEW MOUNTAIN
SHOWERS THURSDAY. ALSO KEPT THE LOW CLOUDS AND FOG IN THE COLUMBIA
BASIN AND ADJACENT VALLEYS AS THIS SYSTEM DOES NOT LOOK STRONG
ENOUGH TO MIX OUT THE INVERSION. AFTER THIS POINT...THE ECMWF THIS
MAKES A SIGNIFICANT DEPARTURE FROM PREVIOUS RUNS AND TRENDED
TOWARDS THE GFS SOLUTION. AM HESITANT TO JUMP FULLY INTO THIS
SOLUTION AS THE GFS HAD BEEN CONSIDERED AN OUTLIER SOLUTION AND WILL
AWAIT THE NEXT ECMWF RUNS TO SEE IF THIS CHANGE IS MAINTAINED. THAT
BEING SAID...THE FLOW LOOKS PRETTY WEAK AND DISORGANIZED THURSDAY
NIGHT THROUGH FRIDAY NIGHT WITH THE GFS AND ECMWF STILL HANDLING IT
SOMEWHAT DIFFERENTLY. HAVE GRADUALLY INCREASED THE POPS AND KEPT THE
LOW CLOUDS AND FOG. THE GFS IS WETTER AND WOULD MIX OUT THE CLOUDS
AND FOG WHILE THE ECMWF IS DRIER AND LIKELY TO CONTINUE THE CLOUDS
AND FOG. HAVE TENDED TOWARDS THE ECMWF BY KEEPING LOW CLOUDS AND FOG
BUT ALSO GRADUALLY INCREASED POPS. BOTH THE ECMWF AND GFS BRING A
STRONG TROUGH INTO THE AREA SATURDAY AND THIS WILL FINALLY MIX OUT
THE CLOUDS AND FOG ONCE AND FOR ALL IF IT HAS NOT ALREADY HAPPENED.
IT WILL ALSO BRING A CHANCE OF SNOW TO THE MOUNTAINS AND A SLIGHT
CHANCE OF RAIN AND SNOW TO THE LOWLANDS SATURDAY THROUGH SUNDAY. THE
GFS SOLUTION BRINGS COLD AIR IN OUT OF CANADA AND LOOKS COLD WHILE
THE ECMWF BRINGS THIS SYSTEM OUT OF THE GULF OF ALASKA AND IS NOT AS
COLD. PERRY
&&
PREVIOUS AVIATION DISCUSSION...18Z TAFS...HIGH PRESSURE CONTINUES TO
DOMINATE LOCAL CONDITIONS AND LOW CLOUDS AND FOG WILL REMAIN OVER
MUCH OF THE AREA FOR THE NEXT 24 HOURS. CEILINGS WILL GENERALLY BE
AT 1500 TO 2500 FEET AGL WITH TOPS AT 4000 TO 4500 FEET THROUGH THIS
EVENING WHEN SUBSIDENCE WILL BEGIN LOWERING THE STRATUS DECK. AN
EXCEPTION WILL BE AT KRDM WHICH WILL HAVE CEILINGS AROUND 500 FEET
AND VISIBILITIES BELOW 3 SM AT TIMES TODAY. WITH THE DECK LOWERING
TONIGHT...SHOULD SEE VISIBILITIES DROP OVERNIGHT TO AROUND 3 SM AS
WELL AT KYKM...KALW AND POSSIBLY KPDT. BRIEF SNOW SHOWERS ARE
POSSIBLE AS WELL WHICH WILL LOWER VISIBILITIES TO 1 SM AT TIMES.
ABOVE 4500 FEET AGL...ONLY SOME HIGH THIN CIRRUS ABOVE 20K FEET AGL
IS EXPECTED. WINDS WILL REMAIN BELOW 10 KTS AT ALL TAF LOCATIONS.
PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 28 29 27 29 / 10 0 0 0
ALW 30 31 29 31 / 10 0 0 0
PSC 31 34 28 34 / 10 0 0 0
YKM 29 32 25 32 / 10 0 0 0
HRI 30 32 27 32 / 10 0 0 0
ELN 29 31 26 31 / 10 0 0 0
RDM 25 27 24 30 / 10 0 0 0
LGD 25 32 26 32 / 10 0 0 0
GCD 18 33 24 33 / 10 0 0 0
DLS 34 34 30 34 / 10 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ042-050-501-
504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR ORZ043-505.
WA...FREEZING FOG ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 12 PM PST TUESDAY FOR WAZ026.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87/83/83
000
FXUS66 KPDT 181754 CCA
AFDPDT
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PENDLETON OR
954 AM PST SUN JAN 18 2009
CORRECTED AVIATION DISCUSSION FOR OMITTED SENTENCE.
.UPDATE...NO MAJOR CHANGES IN THE WORKS AS OF YET ALTHOUGH THE
STRATUS DECK APPEARS TO HAVE BECOME MORE COMPRESSED IN NATURE.
THE BASES ARE NOW MAINLY AROUND 2500 FEET MSL WITH TOPS RANGING FROM
4000 TO 4500 FEET ACCORDING TO PILOT REPORTS AND WEB CAMS. THE
HEIGHT OF THE BASES WOULD NORMALLY GIVE INCLINATION TO REMOVE
FREEZING FOG ADVISORIES FOR THE LOWER ELEVATIONS, BUT SUBSIDENCE
IS EXPECTED TO INCREASE AGAIN BEGINNING THIS AFTERNOON. AS SUCH,
DO THINK THE BASES WILL LOWER AT TIMES TODAY WITH A MORE WIDESPREAD
DROP EXPECTED TONIGHT. ALSO, STILL RECEIVING OCCASIONAL REPORTS OF
SNOW FLURRIES AND LIGHT FREEZING DRIZZLE RESULTING IN SLICK ROAD
CONDITIONS. FELT IT BEST TO MAINTAIN THE ADVISORIES AS MANY OF THE
HAZARDS ARE ALREADY CONTAINED IN THEM RATHER THAN POSSIBLY
CREATING CONFUSION BY BOUNCING ADVISORIES AROUND. WILL ALSO BE
CONSIDERING AN AFTERNOON REISSUE OF THE FREEZING FOG ADVISORY FOR
THE LOWER BASIN AND YAKIMA VALLEY AREAS IF MODEL TRENDS CONTINUE.
AIR STAGNATION ADVISORIES WILL CONTINUE AS PLANNED FOR NOW.
TODAYS AFTERNOON TEMPERATURES WILL CONTINUE TO REMAIN HIGHLY
DEPENDENT OF FOG/STRATUS LOCATIONS SO WILL SEE WHERE THE
NOTORIOUSLY NEBULOUS FOG GETS ADVECTED THIS MORNING AND MAKE A
LATE MORNING ADJUSTMENT THERE IF NEEDED. /JBONK
&&
.AVIATION...18Z TAFS...HIGH PRESSURE CONTINUES TO DOMINATE LOCAL
CONDITIONS AND LOW CLOUDS AND FOG WILL REMAIN OVER MUCH OF THE AREA
FOR THE NEXT 24 HOURS. CEILINGS WILL GENERALLY BE AT 1500 TO 2500
FEET AGL WITH TOPS AT 4000 TO 4500 FEET THROUGH THIS EVENING WHEN
SUBSIDENCE WILL BEGIN LOWERING THE STRATUS DECK. AN EXCEPTION WILL
BE AT KRDM WHICH WILL HAVE CEILINGS AROUND 500 FEET AND VISIBILITIES
BELOW 3 SM AT TIMES TODAY. WITH THE DECK LOWERING TONIGHT...SHOULD
SEE VISIBILITIES DROP OVERNIGHT TO AROUND 3 SM AS WELL AT
KYKM...KALW AND POSSIBLY KPDT. BRIEF SNOW SHOWERS ARE POSSIBLE AS
WELL WHICH WILL LOWER VISIBILITIES TO 1 SM AT TIMES. ABOVE 4500 FEET
AGL...ONLY SOME HIGH THIN CIRRUS ABOVE 20K FEET AGL IS EXPECTED.
WINDS WILL REMAIN BELOW 10 KTS AT ALL TAF LOCATIONS. PERRY
&&
.PREV DISCUSSION... /ISSUED 418 AM PST SUN JAN 18 2009/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST. THE AREA OF FOG AND STATUS OVER THE
INTERIOR NORTHWEST HAS CONTINUED TO GROW AND EXPAND DURING THE PAST
24 HOURS. TOPS OF THIS FOG/STRATUS AREA ARE NOW ROUGHLY BETWEEN 4000
AND 4500 FEET MSL...WITH ONLY THE HIGHEST TERRAIN EXPOSED AND CLEAR.
STRATUS BASES RUN FROM ROUGHLY 1800 FEET TO 2600 FEET MSL. THIS HAS
PUSHED MOST THREATS OF THICK FREEZING FOG TO AT A MINIMUM ABOVE 1800
FEET AND LIKELY ABOVE 2000 FEET. AS SUCH WILL CANCEL FREEZING FOG
ADVISORY IN THE YAKIMA VALLEY WITH THE MORNING FORECAST ISSUANCE.
WILL ALLOW ALL OTHER ADVISORIES TO CONTINUE AS THEY ARE. SHOULD SEE
SOME BURN OFF AROUND THE FRINGES OF THE FOG/STRATUS MASS THIS
AFTERNOON. TEMPS WILL REMAIN SIMILAR TO YESTERDAY...THOUGH MAY BE UP
A DEGREE OR TWO BELOW 2000-2500 FEET AS TEMPS CURRENTLY RUNNING UP A
DEGREE OR TWO. EXPECT A REPEAT OF THE CURRENT OVERNIGHT AND TODAY
CONDITIONS...TONIGHT AND MONDAY WITH THE RIDGE OVERHEAD. BY MONDAY
NIGHT MAY START TO SEE SOME SOUTH FLOW ALOFT. THIS FLOW WOULD BEGIN
TO PUT INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA...RESULTING
IN THE START OF THE TOPS LOWERING AND THE AREAL COVERAGE SHRINKING.
THIS COULD ALSO BEGIN THE PROCESS OF PUSHING THE THICKER FREEZING
FOG AREAS BACK TO LOWER ELEVATIONS. 90
LONG TERM...TUESDAY THROUGH SATURDAY...MEDIUM TO EXTENDED RANGE
MODELS ARE IN FAIR AGREEMENT THROUGH WEDNESDAY WITH THE REGION BEING
DOMINATED BY STRONG HIGH PRESSURE ALOFT. THE GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF. BOTH MODELS ARE INDICATING THE UPPER
RIDGE BEGINNING TO BREAK DOWN STARTING WEDNESDAY AS A WEATHER SYSTEM
MOVES INTO THE SW USA AND ANOTHER TRIES TO MOVE INTO THE PACIFIC
NORTHWEST. THESE TWO UPPER LOWS/TROUGHS RESULT IN THE PATTERN
BECOMING SPLIT AND RATHER DISORGANIZED. THIS SPLIT FLOW THEN
CONTINUES INTO THURSDAY AND THURSDAY NIGHT. AFTER THAT THE MODELS
BEGIN TO DIVERGE MORE SIGNIFICANTLY WITH THE ECMWF SHOWING AN UPPER
RIDGE OVER THE REGION AND THE GFS SHOWING A COLDER TROUGH WITH A
NORTHERLY FLOW BEHIND IT. DUE TO RECENT PAST MAJOR DIFFERENCES
BETWEEN THE EXTENDED MODELS WILL ONLY INTRODUCE SOME COOLING BY THE
END OF THE EXTENDED FORECAST PERIOD WITH LOWERING SNOW LEVELS. WILL
INTRODUCE LIGHT PRECIP IN THE NE MOUNTAINS AND NEAR THE CASCADE
CREST DAY 4-5. BEYOND DAY 5 WILL BUMP UP POPS A BIT PER COORDINATION
WITH SURROUNDING OFFICES AND SINCE THERE IS BETTER AGREEMENT BETWEEN
THE EXTENDED RANGE MODELS. EXPANDED THE PRECIP TO ALSO INCLUDE THE
LOWER ELEVATIONS AS WELL ON DAY 7. FOG AND LOW CLOUDS WILL PERSIST
THROUGH AT LEAST DAY 6 IN THE LOWER COLUMBIA BASIN AND SURROUNDING
VALLEYS AS WELL AS NORTH CENTRAL OREGON. IN THESE AREAS TEMPERATURES
WILL REMAIN COOL DUE TO LACK OF SOLAR HEATING IN THE DAYTIME...BUT
NOT AS COLD AS OTHER AREAS DUE TO A LACK OF OUTWARD LONGWAVE
RADIATION AT NIGHT. IN THE SURROUNDING HIGHER ELEVATIONS TEMPS WILL
REMAIN ABOVE NORMAL THROUGH DAY 6 AND THEN WILL COOL DOWN A LITTLE
FROM DAY 7 ONWARD. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 27 / 0 0 0 0
ALW 31 27 31 29 / 0 0 0 0
PSC 34 29 34 27 / 0 0 0 0
YKM 32 27 32 23 / 0 0 0 0
HRI 32 28 32 26 / 0 0 0 0
ELN 31 26 31 25 / 0 0 0 0
RDM 27 25 27 24 / 0 0 0 0
LGD 32 24 32 26 / 0 0 0 0
GCD 33 28 33 27 / 0 0 0 0
DLS 34 30 34 28 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ043-
050-502-505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87/83
000
FXUS66 KPDT 181751 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
951 AM PST SUN JAN 18 2009
UPDATED AVIATION DISCUSSION.
.UPDATE...NO MAJOR CHANGES IN THE WORKS AS OF YET ALTHOUGH THE
STRATUS DECK APPEARS TO HAVE BECOME MORE COMPRESSED IN NATURE.
THE BASES ARE NOW MAINLY AROUND 2500 FEET MSL WITH TOPS RANGING FROM
4000 TO 4500 FEET ACCORDING TO PILOT REPORTS AND WEB CAMS. THE
HEIGHT OF THE BASES WOULD NORMALLY GIVE INCLINATION TO REMOVE
FREEZING FOG ADVISORIES FOR THE LOWER ELEVATIONS, BUT SUBSIDENCE
IS EXPECTED TO INCREASE AGAIN BEGINNING THIS AFTERNOON. AS SUCH,
DO THINK THE BASES WILL LOWER AT TIMES TODAY WITH A MORE WIDESPREAD
DROP EXPECTED TONIGHT. ALSO, STILL RECEIVING OCCASIONAL REPORTS OF
SNOW FLURRIES AND LIGHT FREEZING DRIZZLE RESULTING IN SLICK ROAD
CONDITIONS. FELT IT BEST TO MAINTAIN THE ADVISORIES AS MANY OF THE
HAZARDS ARE ALREADY CONTAINED IN THEM RATHER THAN POSSIBLY
CREATING CONFUSION BY BOUNCING ADVISORIES AROUND. WILL ALSO BE
CONSIDERING AN AFTERNOON REISSUE OF THE FREEZING FOG ADVISORY FOR
THE LOWER BASIN AND YAKIMA VALLEY AREAS IF MODEL TRENDS CONTINUE.
AIR STAGNATION ADVISORIES WILL CONTINUE AS PLANNED FOR NOW.
TODAYS AFTERNOON TEMPERATURES WILL CONTINUE TO REMAIN HIGHLY
DEPENDENT OF FOG/STRATUS LOCATIONS SO WILL SEE WHERE THE
NOTORIOUSLY NEBULOUS FOG GETS ADVECTED THIS MORNING AND MAKE A
LATE MORNING ADJUSTMENT THERE IF NEEDED. /JBONK
&&
.AVIATION...18Z TAFS...HIGH PRESSURE CONTINUES TO DOMINATE LOCAL
CONDITIONS AND LOW CLOUDS AND FOG WILL REMAIN OVER MUCH OF THE AREA
FOR THE NEXT 24 HOURS. CEILINGS WILL GENERALLY BE AT 1500 TO 2500
FEET AGL WITH TOPS AT 4000 TO 4500 FEET THROUGH THIS EVENING WHEN
SUBSIDENCE WILL BEGIN LOWERING THE STRATUS DECK. AN EXCEPTION WILL
BE AT KRDM WHICH WILL HAVE CEILINGS AROUND 500 FEET AND VISIBILITIES
BELOW 3 SM AT TIMES TODAY. WITH THE DECK LOWERING TONIGHT...SHOULD
SEE VISIBILITIES DROP OVERNIGHT TO AROUND 3 SM AS WELL AT
KYKM...KALW AND POSSIBLY KPDT. ABOVE 4500 FEET AGL...ONLY SOME HIGH
THIN CIRRUS ABOVE 20K FEET AGL IS EXPECTED. WINDS WILL REMAIN BELOW
10 KTS AT ALL TAF LOCATIONS. PERRY
&&
.PREV DISCUSSION... /ISSUED 418 AM PST SUN JAN 18 2009/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST. THE AREA OF FOG AND STATUS OVER THE
INTERIOR NORTHWEST HAS CONTINUED TO GROW AND EXPAND DURING THE PAST
24 HOURS. TOPS OF THIS FOG/STRATUS AREA ARE NOW ROUGHLY BETWEEN 4000
AND 4500 FEET MSL...WITH ONLY THE HIGHEST TERRAIN EXPOSED AND CLEAR.
STRATUS BASES RUN FROM ROUGHLY 1800 FEET TO 2600 FEET MSL. THIS HAS
PUSHED MOST THREATS OF THICK FREEZING FOG TO AT A MINIMUM ABOVE 1800
FEET AND LIKELY ABOVE 2000 FEET. AS SUCH WILL CANCEL FREEZING FOG
ADVISORY IN THE YAKIMA VALLEY WITH THE MORNING FORECAST ISSUANCE.
WILL ALLOW ALL OTHER ADVISORIES TO CONTINUE AS THEY ARE. SHOULD SEE
SOME BURN OFF AROUND THE FRINGES OF THE FOG/STRATUS MASS THIS
AFTERNOON. TEMPS WILL REMAIN SIMILAR TO YESTERDAY...THOUGH MAY BE UP
A DEGREE OR TWO BELOW 2000-2500 FEET AS TEMPS CURRENTLY RUNNING UP A
DEGREE OR TWO. EXPECT A REPEAT OF THE CURRENT OVERNIGHT AND TODAY
CONDITIONS...TONIGHT AND MONDAY WITH THE RIDGE OVERHEAD. BY MONDAY
NIGHT MAY START TO SEE SOME SOUTH FLOW ALOFT. THIS FLOW WOULD BEGIN
TO PUT INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA...RESULTING
IN THE START OF THE TOPS LOWERING AND THE AREAL COVERAGE SHRINKING.
THIS COULD ALSO BEGIN THE PROCESS OF PUSHING THE THICKER FREEZING
FOG AREAS BACK TO LOWER ELEVATIONS. 90
LONG TERM...TUESDAY THROUGH SATURDAY...MEDIUM TO EXTENDED RANGE
MODELS ARE IN FAIR AGREEMENT THROUGH WEDNESDAY WITH THE REGION BEING
DOMINATED BY STRONG HIGH PRESSURE ALOFT. THE GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF. BOTH MODELS ARE INDICATING THE UPPER
RIDGE BEGINNING TO BREAK DOWN STARTING WEDNESDAY AS A WEATHER SYSTEM
MOVES INTO THE SW USA AND ANOTHER TRIES TO MOVE INTO THE PACIFIC
NORTHWEST. THESE TWO UPPER LOWS/TROUGHS RESULT IN THE PATTERN
BECOMING SPLIT AND RATHER DISORGANIZED. THIS SPLIT FLOW THEN
CONTINUES INTO THURSDAY AND THURSDAY NIGHT. AFTER THAT THE MODELS
BEGIN TO DIVERGE MORE SIGNIFICANTLY WITH THE ECMWF SHOWING AN UPPER
RIDGE OVER THE REGION AND THE GFS SHOWING A COLDER TROUGH WITH A
NORTHERLY FLOW BEHIND IT. DUE TO RECENT PAST MAJOR DIFFERENCES
BETWEEN THE EXTENDED MODELS WILL ONLY INTRODUCE SOME COOLING BY THE
END OF THE EXTENDED FORECAST PERIOD WITH LOWERING SNOW LEVELS. WILL
INTRODUCE LIGHT PRECIP IN THE NE MOUNTAINS AND NEAR THE CASCADE
CREST DAY 4-5. BEYOND DAY 5 WILL BUMP UP POPS A BIT PER COORDINATION
WITH SURROUNDING OFFICES AND SINCE THERE IS BETTER AGREEMENT BETWEEN
THE EXTENDED RANGE MODELS. EXPANDED THE PRECIP TO ALSO INCLUDE THE
LOWER ELEVATIONS AS WELL ON DAY 7. FOG AND LOW CLOUDS WILL PERSIST
THROUGH AT LEAST DAY 6 IN THE LOWER COLUMBIA BASIN AND SURROUNDING
VALLEYS AS WELL AS NORTH CENTRAL OREGON. IN THESE AREAS TEMPERATURES
WILL REMAIN COOL DUE TO LACK OF SOLAR HEATING IN THE DAYTIME...BUT
NOT AS COLD AS OTHER AREAS DUE TO A LACK OF OUTWARD LONGWAVE
RADIATION AT NIGHT. IN THE SURROUNDING HIGHER ELEVATIONS TEMPS WILL
REMAIN ABOVE NORMAL THROUGH DAY 6 AND THEN WILL COOL DOWN A LITTLE
FROM DAY 7 ONWARD. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 27 / 0 0 0 0
ALW 31 27 31 29 / 0 0 0 0
PSC 34 29 34 27 / 0 0 0 0
YKM 32 27 32 23 / 0 0 0 0
HRI 32 28 32 26 / 0 0 0 0
ELN 31 26 31 25 / 0 0 0 0
RDM 27 25 27 24 / 0 0 0 0
LGD 32 24 32 26 / 0 0 0 0
GCD 33 28 33 27 / 0 0 0 0
DLS 34 30 34 28 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ043-
050-502-505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87/83
000
FXUS66 KPDT 181648
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
848 AM PST SUN JAN 18 2009
.UPDATE...NO MAJOR CHANGES IN THE WORKS AS OF YET ALTHOUGH THE
STRATUS DECK APPEARS TO HAVE BECOME MORE COMPRESSED IN NATURE.
THE BASES ARE NOW MAINLY AROUND 2500 FEET MSL WITH TOPS RANGING FROM
4000 TO 4500 FEET ACCORDING TO PILOT REPORTS AND WEB CAMS. THE
HEIGHT OF THE BASES WOULD NORMALLY GIVE INCLINATION TO REMOVE
FREEZING FOG ADVISORIES FOR THE LOWER ELEVATIONS, BUT SUBSIDENCE
IS EXPECTED TO INCREASE AGAIN BEGINNING THIS AFTERNOON. AS SUCH,
DO THINK THE BASES WILL LOWER AT TIMES TODAY WITH A MORE WIDESPREAD
DROP EXPECTED TONIGHT. ALSO, STILL RECEIVING OCCASIONAL REPORTS OF
SNOW FLURRIES AND LIGHT FREEZING DRIZZLE RESULTING IN SLICK ROAD
CONDITIONS. FELT IT BEST TO MAINTAIN THE ADVISORIES AS MANY OF THE
HAZARDS ARE ALREADY CONTAINED IN THEM RATHER THAN POSSIBLY
CREATING CONFUSION BY BOUNCING ADVISORIES AROUND. WILL ALSO BE
CONSIDERING AN AFTERNOON REISSUE OF THE FREEZING FOG ADVISORY FOR
THE LOWER BASIN AND YAKIMA VALLEY AREAS IF MODEL TRENDS CONTINUE.
AIR STAGNATION ADVISORIES WILL CONTINUE AS PLANNED FOR NOW.
TODAYS AFTERNOON TEMPERATURES WILL CONTINUE TO REMAIN HIGHLY
DEPENDENT OF FOG/STRATUS LOCATIONS SO WILL SEE WHERE THE
NOTORIOUSLY NEBULOUS FOG GETS ADVECTED THIS MORNING AND MAKE A
LATE MORNING ADJUSTMENT THERE IF NEEDED. /JBONK
&&
.PREV DISCUSSION... /ISSUED 418 AM PST SUN JAN 18 2009/
SHORT TERM...TODAY THROUGH MONDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST. THE AREA OF FOG AND STATUS OVER THE
INTERIOR NORTHWEST HAS CONTINUED TO GROW AND EXPAND DURING THE PAST
24 HOURS. TOPS OF THIS FOG/STRATUS AREA ARE NOW ROUGHLY BETWEEN 4000
AND 4500 FEET MSL...WITH ONLY THE HIGHEST TERRAIN EXPOSED AND CLEAR.
STRATUS BASES RUN FROM ROUGHLY 1800 FEET TO 2600 FEET MSL. THIS HAS
PUSHED MOST THREATS OF THICK FREEZING FOG TO AT A MINIMUM ABOVE 1800
FEET AND LIKELY ABOVE 2000 FEET. AS SUCH WILL CANCEL FREEZING FOG
ADVISORY IN THE YAKIMA VALLEY WITH THE MORNING FORECAST ISSUANCE.
WILL ALLOW ALL OTHER ADVISORIES TO CONTINUE AS THEY ARE. SHOULD SEE
SOME BURN OFF AROUND THE FRINGES OF THE FOG/STRATUS MASS THIS
AFTERNOON. TEMPS WILL REMAIN SIMILAR TO YESTERDAY...THOUGH MAY BE UP
A DEGREE OR TWO BELOW 2000-2500 FEET AS TEMPS CURRENTLY RUNNING UP A
DEGREE OR TWO. EXPECT A REPEAT OF THE CURRENT OVERNIGHT AND TODAY
CONDITIONS...TONIGHT AND MONDAY WITH THE RIDGE OVERHEAD. BY MONDAY
NIGHT MAY START TO SEE SOME SOUTH FLOW ALOFT. THIS FLOW WOULD BEGIN
TO PUT INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA...RESULTING
IN THE START OF THE TOPS LOWERING AND THE AREAL COVERAGE SHRINKING.
THIS COULD ALSO BEGIN THE PROCESS OF PUSHING THE THICKER FREEZING
FOG AREAS BACK TO LOWER ELEVATIONS. 90
LONG TERM...TUESDAY THROUGH SATURDAY...MEDIUM TO EXTENDED RANGE
MODELS ARE IN FAIR AGREEMENT THROUGH WEDNESDAY WITH THE REGION BEING
DOMINATED BY STRONG HIGH PRESSURE ALOFT. THE GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF. BOTH MODELS ARE INDICATING THE UPPER
RIDGE BEGINNING TO BREAK DOWN STARTING WEDNESDAY AS A WEATHER SYSTEM
MOVES INTO THE SW USA AND ANOTHER TRIES TO MOVE INTO THE PACIFIC
NORTHWEST. THESE TWO UPPER LOWS/TROUGHS RESULT IN THE PATTERN
BECOMING SPLIT AND RATHER DISORGANIZED. THIS SPLIT FLOW THEN
CONTINUES INTO THURSDAY AND THURSDAY NIGHT. AFTER THAT THE MODELS
BEGIN TO DIVERGE MORE SIGNIFICANTLY WITH THE ECMWF SHOWING AN UPPER
RIDGE OVER THE REGION AND THE GFS SHOWING A COLDER TROUGH WITH A
NORTHERLY FLOW BEHIND IT. DUE TO RECENT PAST MAJOR DIFFERENCES
BETWEEN THE EXTENDED MODELS WILL ONLY INTRODUCE SOME COOLING BY THE
END OF THE EXTENDED FORECAST PERIOD WITH LOWERING SNOW LEVELS. WILL
INTRODUCE LIGHT PRECIP IN THE NE MOUNTAINS AND NEAR THE CASCADE
CREST DAY 4-5. BEYOND DAY 5 WILL BUMP UP POPS A BIT PER COORDINATION
WITH SURROUNDING OFFICES AND SINCE THERE IS BETTER AGREEMENT BETWEEN
THE EXTENDED RANGE MODELS. EXPANDED THE PRECIP TO ALSO INCLUDE THE
LOWER ELEVATIONS AS WELL ON DAY 7. FOG AND LOW CLOUDS WILL PERSIST
THROUGH AT LEAST DAY 6 IN THE LOWER COLUMBIA BASIN AND SURROUNDING
VALLEYS AS WELL AS NORTH CENTRAL OREGON. IN THESE AREAS TEMPERATURES
WILL REMAIN COOL DUE TO LACK OF SOLAR HEATING IN THE DAYTIME...BUT
NOT AS COLD AS OTHER AREAS DUE TO A LACK OF OUTWARD LONGWAVE
RADIATION AT NIGHT. IN THE SURROUNDING HIGHER ELEVATIONS TEMPS WILL
REMAIN ABOVE NORMAL THROUGH DAY 6 AND THEN WILL COOL DOWN A LITTLE
FROM DAY 7 ONWARD. 88
AVIATION...12Z TAFS...LOW CLOUDS AND FOG WILL PERSIST OVER THE AREA
THROUGH TONIGHT UNDER STRONG HIGH PRESSURE ALOFT. CEILINGS WILL
GENERALLY RANGE FROM 1500 TO 2500 FT AGL WITH VISIBILITIES MOSTLY
BETWEEN 4-6SM. THERE WILL BE LOCAL AREAS OF MVFR OR IFR CONDITIONS
ESPECIALLY IN AND AROUND KALW...KRDM AND KYKM. LOCATIONS ABOVE 4500
FEET WILL HAVE ONLY SOME HIGH THIN CIRRUS AT TIMES AT HEIGHTS
GREATER THAN 20K FT AGL. WINDS WILL BE LIGHT AT ALL STATIONS AND
LESS THAN 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 27 / 0 0 0 0
ALW 31 27 31 29 / 0 0 0 0
PSC 34 29 34 27 / 0 0 0 0
YKM 32 27 32 23 / 0 0 0 0
HRI 32 28 32 26 / 0 0 0 0
ELN 31 26 31 25 / 0 0 0 0
RDM 27 25 27 24 / 0 0 0 0
LGD 32 24 32 26 / 0 0 0 0
GCD 33 28 33 27 / 0 0 0 0
DLS 34 30 34 28 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ043-
050-502-505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87
000
FXUS66 KPDT 181335 CCA
AFDPDT
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PENDLETON OR
418 AM PST SUN JAN 18 2009
CORRECTED POINT TEMPERATURE FORECAST FOR PSC
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST. THE AREA OF FOG AND STATUS OVER THE
INTERIOR NORTHWEST HAS CONTINUED TO GROW AND EXPAND DURING THE PAST
24 HOURS. TOPS OF THIS FOG/STRATUS AREA ARE NOW ROUGHLY BETWEEN 4000
AND 4500 FEET MSL...WITH ONLY THE HIGHEST TERRAIN EXPOSED AND CLEAR.
STRATUS BASES RUN FROM ROUGHLY 1800 FEET TO 2600 FEET MSL. THIS HAS
PUSHED MOST THREATS OF THICK FREEZING FOG TO AT A MINIMUM ABOVE 1800
FEET AND LIKELY ABOVE 2000 FEET. AS SUCH WILL CANCEL FREEZING FOG
ADVISORY IN THE YAKIMA VALLEY WITH THE MORNING FORECAST ISSUANCE.
WILL ALLOW ALL OTHER ADVISORIES TO CONTINUE AS THEY ARE. SHOULD SEE
SOME BURN OFF AROUND THE FRINGES OF THE FOG/STRATUS MASS THIS
AFTERNOON. TEMPS WILL REMAIN SIMILAR TO YESTERDAY...THOUGH MAY BE UP
A DEGREE OR TWO BELOW 2000-2500 FEET AS TEMPS CURRENTLY RUNNING UP A
DEGREE OR TWO. EXPECT A REPEAT OF THE CURRENT OVERNIGHT AND TODAY
CONDITIONS...TONIGHT AND MONDAY WITH THE RIDGE OVERHEAD. BY MONDAY
NIGHT MAY START TO SEE SOME SOUTH FLOW ALOFT. THIS FLOW WOULD BEGIN
TO PUT INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA...RESULTING
IN THE START OF THE TOPS LOWERING AND THE AREAL COVERAGE SHRINKING.
THIS COULD ALSO BEGIN THE PROCESS OF PUSHING THE THICKER FREEZING
FOG AREAS BACK TO LOWER ELEVATIONS. 90
.LONG TERM...TUESDAY THROUGH SATURDAY...MEDIUM TO EXTENDED RANGE
MODELS ARE IN FAIR AGREEMENT THROUGH WEDNESDAY WITH THE REGION BEING
DOMINATED BY STRONG HIGH PRESSURE ALOFT. THE GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF. BOTH MODELS ARE INDICATING THE UPPER
RIDGE BEGINNING TO BREAK DOWN STARTING WEDNESDAY AS A WEATHER SYSTEM
MOVES INTO THE SW USA AND ANOTHER TRIES TO MOVE INTO THE PACIFIC
NORTHWEST. THESE TWO UPPER LOWS/TROUGHS RESULT IN THE PATTERN
BECOMING SPLIT AND RATHER DISORGANIZED. THIS SPLIT FLOW THEN
CONTINUES INTO THURSDAY AND THURSDAY NIGHT. AFTER THAT THE MODELS
BEGIN TO DIVERGE MORE SIGNIFICANTLY WITH THE ECMWF SHOWING AN UPPER
RIDGE OVER THE REGION AND THE GFS SHOWING A COLDER TROUGH WITH A
NORTHERLY FLOW BEHIND IT. DUE TO RECENT PAST MAJOR DIFFERENCES
BETWEEN THE EXTENDED MODELS WILL ONLY INTRODUCE SOME COOLING BY THE
END OF THE EXTENDED FORECAST PERIOD WITH LOWERING SNOW LEVELS. WILL
INTRODUCE LIGHT PRECIP IN THE NE MOUNTAINS AND NEAR THE CASCADE
CREST DAY 4-5. BEYOND DAY 5 WILL BUMP UP POPS A BIT PER COORDINATION
WITH SURROUNDING OFFICES AND SINCE THERE IS BETTER AGREEMENT BETWEEN
THE EXTENDED RANGE MODELS. EXPANDED THE PRECIP TO ALSO INCLUDE THE
LOWER ELEVATIONS AS WELL ON DAY 7. FOG AND LOW CLOUDS WILL PERSIST
THROUGH AT LEAST DAY 6 IN THE LOWER COLUMBIA BASIN AND SURROUNDING
VALLEYS AS WELL AS NORTH CENTRAL OREGON. IN THESE AREAS TEMPERATURES
WILL REMAIN COOL DUE TO LACK OF SOLAR HEATING IN THE DAYTIME...BUT
NOT AS COLD AS OTHER AREAS DUE TO A LACK OF OUTWARD LONGWAVE
RADIATION AT NIGHT. IN THE SURROUNDING HIGHER ELEVATIONS TEMPS WILL
REMAIN ABOVE NORMAL THROUGH DAY 6 AND THEN WILL COOL DOWN A LITTLE
FROM DAY 7 ONWARD. 88
&&
.AVIATION...12Z TAFS...LOW CLOUDS AND FOG WILL PERSIST OVER THE AREA
THROUGH TONIGHT UNDER STRONG HIGH PRESSURE ALOFT. CEILINGS WILL
GENERALLY RANGE FROM 1500 TO 2500 FT AGL WITH VISIBILITIES MOSTLY
BETWEEN 4-6SM. THERE WILL BE LOCAL AREAS OF MVFR OR IFR CONDITIONS
ESPECIALLY IN AND AROUND KALW...KRDM AND KYKM. LOCATIONS ABOVE 4500
FEET WILL HAVE ONLY SOME HIGH THIN CIRRUS AT TIMES AT HEIGHTS
GREATER THAN 20K FT AGL. WINDS WILL BE LIGHT AT ALL STATIONS AND
LESS THAN 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 27 / 0 0 0 0
ALW 31 27 31 29 / 0 0 0 0
PSC 34 29 35 27 / 0 0 0 0
YKM 32 27 32 23 / 0 0 0 0
HRI 32 28 32 26 / 0 0 0 0
ELN 31 26 31 25 / 0 0 0 0
RDM 27 25 27 24 / 0 0 0 0
LGD 32 24 32 26 / 0 0 0 0
GCD 33 28 33 27 / 0 0 0 0
DLS 34 30 34 28 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ043-
050-502-505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
90/88/88
000
FXUS66 KPDT 181218 AAA
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
418 AM PST SUN JAN 18 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST. THE AREA OF FOG AND STATUS OVER THE
INTERIOR NORTHWEST HAS CONTINUED TO GROW AND EXPAND DURING THE PAST
24 HOURS. TOPS OF THIS FOG/STRATUS AREA ARE NOW ROUGHLY BETWEEN 4000
AND 4500 FEET MSL...WITH ONLY THE HIGHEST TERRAIN EXPOSED AND CLEAR.
STRATUS BASES RUN FROM ROUGHLY 1800 FEET TO 2600 FEET MSL. THIS HAS
PUSHED MOST THREATS OF THICK FREEZING FOG TO AT A MINIMUM ABOVE 1800
FEET AND LIKELY ABOVE 2000 FEET. AS SUCH WILL CANCEL FREEZING FOG
ADVISORY IN THE YAKIMA VALLEY WITH THE MORNING FORECAST ISSUANCE.
WILL ALLOW ALL OTHER ADVISORIES TO CONTINUE AS THEY ARE. SHOULD SEE
SOME BURN OFF AROUND THE FRINGES OF THE FOG/STRATUS MASS THIS
AFTERNOON. TEMPS WILL REMAIN SIMILAR TO YESTERDAY...THOUGH MAY BE UP
A DEGREE OR TWO BELOW 2000-2500 FEET AS TEMPS CURRENTLY RUNNING UP A
DEGREE OR TWO. EXPECT A REPEAT OF THE CURRENT OVERNIGHT AND TODAY
CONDITIONS...TONIGHT AND MONDAY WITH THE RIDGE OVERHEAD. BY MONDAY
NIGHT MAY START TO SEE SOME SOUTH FLOW ALOFT. THIS FLOW WOULD BEGIN
TO PUT INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA...RESULTING
IN THE START OF THE TOPS LOWERING AND THE AREAL COVERAGE SHRINKING.
THIS COULD ALSO BEGIN THE PROCESS OF PUSHING THE THICKER FREEZING
FOG AREAS BACK TO LOWER ELEVATIONS. 90
.LONG TERM...TUESDAY THROUGH SATURDAY...MEDIUM TO EXTENDED RANGE
MODELS ARE IN FAIR AGREEMENT THROUGH WEDNESDAY WITH THE REGION BEING
DOMINATED BY STRONG HIGH PRESSURE ALOFT. THE GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF. BOTH MODELS ARE INDICATING THE UPPER
RIDGE BEGINNING TO BREAK DOWN STARTING WEDNESDAY AS A WEATHER SYSTEM
MOVES INTO THE SW USA AND ANOTHER TRIES TO MOVE INTO THE PACIFIC
NORTHWEST. THESE TWO UPPER LOWS/TROUGHS RESULT IN THE PATTERN
BECOMING SPLIT AND RATHER DISORGANIZED. THIS SPLIT FLOW THEN
CONTINUES INTO THURSDAY AND THURSDAY NIGHT. AFTER THAT THE MODELS
BEGIN TO DIVERGE MORE SIGNIFICANTLY WITH THE ECMWF SHOWING AN UPPER
RIDGE OVER THE REGION AND THE GFS SHOWING A COLDER TROUGH WITH A
NORTHERLY FLOW BEHIND IT. DUE TO RECENT PAST MAJOR DIFFERENCES
BETWEEN THE EXTENDED MODELS WILL ONLY INTRODUCE SOME COOLING BY THE
END OF THE EXTENDED FORECAST PERIOD WITH LOWERING SNOW LEVELS. WILL
INTRODUCE LIGHT PRECIP IN THE NE MOUNTAINS AND NEAR THE CASCADE
CREST DAY 4-5. BEYOND DAY 5 WILL BUMP UP POPS A BIT PER COORDINATION
WITH SURROUNDING OFFICES AND SINCE THERE IS BETTER AGREEMENT BETWEEN
THE EXTENDED RANGE MODELS. EXPANDED THE PRECIP TO ALSO INCLUDE THE
LOWER ELEVATIONS AS WELL ON DAY 7. FOG AND LOW CLOUDS WILL PERSIST
THROUGH AT LEAST DAY 6 IN THE LOWER COLUMBIA BASIN AND SURROUNDING
VALLEYS AS WELL AS NORTH CENTRAL OREGON. IN THESE AREAS TEMPERATURES
WILL REMAIN COOL DUE TO LACK OF SOLAR HEATING IN THE DAYTIME...BUT
NOT AS COLD AS OTHER AREAS DUE TO A LACK OF OUTWARD LONGWAVE
RADIATION AT NIGHT. IN THE SURROUNDING HIGHER ELEVATIONS TEMPS WILL
REMAIN ABOVE NORMAL THROUGH DAY 6 AND THEN WILL COOL DOWN A LITTLE
FROM DAY 7 ONWARD. 88
&&
.AVIATION...12Z TAFS...LOW CLOUDS AND FOG WILL PERSIST OVER THE AREA
THROUGH TONIGHT UNDER STRONG HIGH PRESSURE ALOFT. CEILINGS WILL
GENERALLY RANGE FROM 1500 TO 2500 FT AGL WITH VISIBILITIES MOSTLY
BETWEEN 4-6SM. THERE WILL BE LOCAL AREAS OF MVFR OR IFR CONDITIONS
ESPECIALLY IN AND AROUND KALW...KRDM AND KYKM. LOCATIONS ABOVE 4500
FEET WILL HAVE ONLY SOME HIGH THIN CIRRUS AT TIMES AT HEIGHTS
GREATER THAN 20K FT AGL. WINDS WILL BE LIGHT AT ALL STATIONS AND
LESS THAN 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 27 / 0 0 0 0
ALW 31 27 31 29 / 0 0 0 0
PSC 35 29 35 27 / 0 0 0 0
YKM 32 27 32 23 / 0 0 0 0
HRI 32 28 32 26 / 0 0 0 0
ELN 31 26 31 25 / 0 0 0 0
RDM 27 25 27 24 / 0 0 0 0
LGD 32 24 32 26 / 0 0 0 0
GCD 33 28 33 27 / 0 0 0 0
DLS 34 30 34 28 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ043-
050-502-505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
90/88/88
000
FXUS66 KPDT 181100
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
300 AM PST SUN JAN 18 2009
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...THE UPPER RIDGE WILL
REMAIN OVER THE WESTERN U.S. THROUGH THIS PERIOD...THOUGH IT/S AXIS
WILL CONTINUE TO SHIFT EAST. THE AREA OF FOG AND STATUS OVER THE
INTERIOR NORTHWEST HAS CONTINUED TO GROW AND EXPAND DURING THE PAST
24 HOURS. TOPS OF THIS FOG/STRATUS AREA ARE NOW ROUGHLY BETWEEN 4000
AND 4500 FEET MSL...WITH ONLY THE HIGHEST TERRAIN EXPOSED AND CLEAR.
STRATUS BASES RUN FROM ROUGHLY 1800 FEET TO 2600 FEET MSL. THIS HAS
PUSHED MOST THREATS OF THICK FREEZING FOG TO AT A MINIMUM ABOVE 1800
FEET AND LIKELY ABOVE 2000 FEET. AS SUCH WILL CANCEL FREEZING FOG
ADVISORY IN THE YAKIMA VALLEY WITH THE MORNING FORECAST ISSUANCE.
WILL ALLOW ALL OTHER ADVISORIES TO CONTINUE AS THEY ARE. SHOULD SEE
SOME BURN OFF AROUND THE FRINGES OF THE FOG/STRATUS MASS THIS
AFTERNOON. TEMPS WILL REMAIN SIMILAR TO YESTERDAY...THOUGH MAY BE UP
A DEGREE OR TWO BELOW 2000-2500 FEET AS TEMPS CURRENTLY RUNNING UP A
DEGREE OR TWO. EXPECT A REPEAT OF THE CURRENT OVERNIGHT AND TODAY
CONDITIONS...TONIGHT AND MONDAY WITH THE RIDGE OVERHEAD. BY MONDAY
NIGHT MAY START TO SEE SOME SOUTH FLOW ALOFT. THIS FLOW WOULD BEGIN
TO PUT INCREASING DOWNWARD FORCE ON THE FOG/STRATUS AREA...RESULTING
IN THE START OF THE TOPS LOWERING AND THE AREAL COVERAGE SHRINKING.
THIS COULD ALSO BEGIN THE PROCESS OF PUSHING THE THICKER FREEZING
FOG AREAS BACK TO LOWER ELEVATIONS. 90
.LONG TERM...TUESDAY THROUGH SATURDAY...MEDIUM TO EXTENDED RANGE
MODELS ARE IN FAIR AGREEMENT THROUGH WEDNESDAY WITH THE REGION BEING
DOMINATED BY STRONG HIGH PRESSURE ALOFT. THE GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF. BOTH MODELS ARE INDICATING THE UPPER
RIDGE BEGINNING TO BREAK DOWN STARTING WEDNESDAY AS A WEATHER SYSTEM
MOVES INTO THE SW USA AND ANOTHER TRIES TO MOVE INTO THE PACIFIC
NORTHWEST. THESE TWO UPPER LOWS/TROUGHS RESULT IN THE PATTERN
BECOMING SPLIT AND RATHER DISORGANIZED. THIS SPLIT FLOW THEN
CONTINUES INTO THURSDAY AND THURSDAY NIGHT. AFTER THAT THE MODELS
BEGIN TO DIVERGE MORE SIGNIFICANTLY WITH THE ECMWF SHOWING AN UPPER
RIDGE OVER THE REGION AND THE GFS SHOWING A COLDER TROUGH WITH A
NORTHERLY FLOW BEHIND IT. DUE TO RECENT PAST MAJOR DIFFERENCES
BETWEEN THE EXTENDED MODELS WILL ONLY INTRODUCE SOME COOLING BY THE
END OF THE EXTENDED FORECAST PERIOD WITH LOWERING SNOW LEVELS. WILL
INTRODUCE LIGHT PRECIP IN THE NE MOUNTAINS AND NEAR THE CASCADE
CREST DAY 4-5. BEYOND DAY 5 WILL BUMP UP POPS A BIT PER COORDINATION
WITH SURROUNDING OFFICES AND SINCE THERE IS BETTER AGREEMENT BETWEEN
THE EXTENDED RANGE MODELS. EXPANDED THE PRECIP TO ALSO INCLUDE THE
LOWER ELEVATIONS AS WELL ON DAY 7. FOG AND LOW CLOUDS WILL PERSIST
THROUGH AT LEAST DAY 6 IN THE LOWER COLUMBIA BASIN AND SURROUNDING
VALLEYS AS WELL AS NORTH CENTRAL OREGON. IN THESE AREAS TEMPERATURES
WILL REMAIN COOL DUE TO LACK OF SOLAR HEATING IN THE DAYTIME...BUT
NOT AS COLD AS OTHER AREAS DUE TO A LACK OF OUTWARD LONGWAVE
RADIATION AT NIGHT. IN THE SURROUNDING HIGHER ELEVATIONS TEMPS WILL
REMAIN ABOVE NORMAL THROUGH DAY 6 AND THEN WILL COOL DOWN A LITTLE
FROM DAY 7 ONWARD. 88
&&
.AVIATION...PREVIOUS DISCUSSION 06Z TAFS...HIGH PRESSURE AND AN
INVERSION WILL KEEP LOW CLOUDS AND FOG IN AREAS BELOW 4500 FEET FOR
THE NEXT 24 HOURS. EXPECT GENERALLY MVFR/IFR CEILINGS AND VFR
VISIBILITIES ESPECIALLY AT...KALW...KPDT AT TIMES TONIGHT AND INTO
TOMORROW. LIFR CONDITIONS DUE TO LOWERING CEILINGS AND VSBY ARE
POSSIBLE AT KRDM INTO TOMORROW AS WELL. ABOVE 4500 FEET MOSTLY CLEAR
SKIES WITH ONLY A FEW CIRRUS CLOUDS CAN BE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 27 / 0 0 0 0
ALW 31 27 31 29 / 0 0 0 0
PSC 35 29 35 27 / 0 0 0 0
YKM 32 27 32 23 / 0 0 0 0
HRI 32 28 32 26 / 0 0 0 0
ELN 31 26 31 25 / 0 0 0 0
RDM 27 25 27 24 / 0 0 0 0
LGD 32 24 32 26 / 0 0 0 0
GCD 33 28 33 27 / 0 0 0 0
DLS 34 30 34 28 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ043-
050-502-505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
90/88/97
000
FXUS66 KPDT 180430 AAA
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
820 PM PST SAT JAN 17 2009
.SHORT TERM...HIGH PRESSURE CONTINUES TO DOMINATE THE AREAS WEATHER
WITH DRY CONDITIONS. ALSO AREAS OF FOG AND FREEZING FOG WILL PERSIST
WITH ADVISORIES IN PLACE FOR TONIGHT AND INTO TOMORROW ACROSS THE
FOOTHILLS OF THE BLUE MOUNTAINS...YAKIMA/KITTITAS VALLEYS...AND
CENTRAL OREGON INCLUDING THE JOHN DAY AREA. PLAN TO ADJUST OVERNIGHT
LOW TEMPS DOWNWARD ACROSS PORTIONS OF THE AREA SOON. OTHERWISE THE
REMAINDER OF THE SHORT TERM FORECAST APPEARS ON TRACK FOR NOW.
&&
.AVIATION...HIGH PRESSURE AND AN INVERSION WILL KEEP LOW CLOUDS AND
FOG IN AREAS BELOW 4500 FEET FOR THE NEXT 24 HOURS. EXPECT GENERALLY
MVFR/IFR CEILINGS AND VFR VISIBILITIES ESPECIALLY AT...KALW...KPDT
AT TIMES TONIGHT AND INTO TOMORROW. LIFR CONDITIONS DUE TO LOWERING
CEILINGS AND VSBY ARE POSSIBLE AT KRDM INTO TOMORROW AS WELL. ABOVE
4500 FEET MOSTLY CLEAR SKIES WITH ONLY A FEW CIRRUS CLOUDS CAN BE
EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 26 29 26 29 / 0 0 0 0
ALW 27 30 27 30 / 0 0 0 0
PSC 29 31 29 31 / 0 0 0 0
YKM 26 29 27 29 / 0 0 0 0
HRI 28 31 28 31 / 0 0 0 0
ELN 27 30 26 30 / 0 0 0 0
RDM 25 29 25 29 / 0 0 0 0
LGD 24 31 24 31 / 0 0 0 0
GCD 27 35 28 35 / 0 0 0 0
DLS 31 36 30 36 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST SUNDAY FOR ORZ043-050-502-
505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-027-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
97
000
FXUS66 KPDT 172202
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
202 PM PST SAT JAN 17 2009
.SHORT TERM...TONIGHT THROUGH TUESDAY...NO MAJOR CHANGES TO THE
UPPER LEVEL PATTERN AS RIDGING WILL REMAIN DOMINANT THROUGH THE
SHORT TERM. MAIN CHALLENGE REVOLVES AROUND WHERE THE TOP OF THE
INVERSION AND RESULTING STRATUS DECK WILL BE. UPPER LEVEL SUBSIDENCE
HAS WEAKENED SOMEWHAT OVER THE LAST 24 HOURS AND HAS ALLOWED THE TOP
OF THE DECK TO REACH AROUND 4000 FEET MSL TO THE NORTH AND 4500 FEET
MSL TO THE SOUTH. LITTLE MOVEMENT HAS BEEN OBSERVED SINCE SUNRISE
OTHER THAN SOME FRINGE EXPANSION AND REDUCTION. FEEL THAT FURTHER
WEAKENING IN THE SUBSIDENCE AND MINOR REPOSITIONING OF WEAK PRESSURE
GRADIENTS WILL ALLOW THE DECK TO EXPAND FURTHER SOUTH AND EAST
ACROSS CENTRAL AND EAST CENTRAL OREGON AS WELL AS BEGINNING TO
REALLY ENVELOP THE LOWER VALLEYS ADJOINING THE LOW COLUMBIA RIVER
DRAINAGES. AS SUCH...FELT THE NEED TO EXPAND THE FREEZING FOG
ADVISORY ACROSS THE JOHN DAY BASIN ZONE AND THE NORTHERN BLUE
MOUNTAIN ZONE AS THE FREEZING FOG AND POTENTIAL FREEZING DRIZZLE
WILL LIKELY INCREASE TRAVEL HAZARDS ALONG MAJOR ROUTES. WILL ALSO
EXTEND THE ADVISORY IN TIME ANOTHER 24 TO 48 HOURS AS THIS DECK WILL
NOT BE LEAVING THE GENERAL AREA ANYTIME SOON. SUBSIDENCE DOES
INCREASE AGAIN LATER TOMORROW AFTERNOON WITH PORTIONS OF CENTRAL AND
EAST CENTRAL OREGON IN ADDITION TO THE BLUE MOUNTAINS LIKELY
BECOMING FOG FREE ONCE AGAIN BY TOMORROW EVENING AS THE TOP OF THE
INVERSION DROPS TO LOWER ALTITUDES.
AN AIR STAGNATION ADVISORY HAS BEEN ISSUED FOR THE JOHN DAY BASIN
ZONE AND THE ADVISORY FOR OTHER ZONES WILL REMAIN IN PLACE THROUGH
AT LEAST TUESDAY AND WOULD NOT BE SURPRISED TO SEE IT EXTENDED EVEN
FURTHER INTO NEXT WEEK. TEMPERATURES BELOW THE FOG/STRATUS WILL
CONTINUE TO REMAIN COOL WITH MUCH WARMER TEMPERATURES ABOVE THE
DECK. /JBONK
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...HIGH PRESSURE WILL
CONTINUE IN PLACE OVER THE PACIFIC NORTHWEST TUESDAY NIGHT ALTHOUGH
IT WILL MOVE EASTWARD AS A TROUGH APPROACHES THE COAST. THIS WILL
GIVE THE AREA ANOTHER NIGHT OF LOW CLOUDS AND FREEZING FOG BELOW
4000 FEET AND MOSTLY CLEAR SKIES AND TEMPERATURES IN THE 20S TO LOW
30S IN THE MOUNTAINS. MODELS DISAGREE ABOUT THE APPROACHING TROUGH
WITH THE GFS BRINGING A FRONTAL SYSTEM THROUGH WEDNESDAY AND
WEDNESDAY NIGHT FOLLOWED BY RIDGING THURSDAY AND THURSDAY NIGHT AND
A COUPLE OF SYSTEMS MOVING THROUGH FRIDAY AND SATURDAY. THE ECMWF
HAS A SPLITTING SYSTEM WEDNESDAY WITH THE MAIN ENERGY PASSING TO OUR
NORTH AND SOUTH WITH THE RIDGE WEAKENED BUT INTACT THROUGH SATURDAY.
HAVE SIDED WITH THE ECMWF BASED ON ITS RECENT SUPERIOR PERFORMANCE
AND THUS KEPT THE INVERSION IN THE COLUMBIA BASIN AND NORTH CENTRAL
OREGON THROUGH SATURDAY. THIS WILL CONTINUE THE LOW CLOUDS AND FOG
BELOW 4000 FEET WITH NEAR TO BELOW FREEZING TEMPERATURES WHILE ABOVE
THAT PARTLY CLOUDY SKIES AND DAYTIME TEMPERATURES IN THE 40S CAN BE
EXPECTED. HAVE PUT A SLIGHT CHANCE OF RAIN AND SNOW SHOWERS IN THE
MOUNTAINS THURSDAY THROUGH SATURDAY IN CASE THE GFS PROVES ACCURATE.
WINDS WILL BE LIGHT THROUGH THE PERIOD. PERRY
&&
.AVIATION...00Z TAFS...HIGH PRESSURE AND AN INVERSION WILL KEEP LOW
CLOUDS AND FOG IN AREAS BELOW 4500 FEET FOR THE NEXT 24 HOURS.
EXPECT GENERALLY MVFR/IFR CEILINGS AND VFR VISIBILITIES ALTHOUGH
LIFR CEILINGS WILL BE POSSIBLE AT KALW AND KPDT AT TIMES TONIGHT.
ANOTHER EXCEPTION WILL BE KRDM WHICH WILL SEE MVFR/IFR CEILINGS AND
VFR VISIBILITIES AS THE STRATUS DECK IS AT OR NEAR THE SURFACE.
ABOVE 4500 FEET MOSTLY CLEAR SKIES WITH ONLY A FEW CIRRUS CLOUDS CAN
BE EXPECTED. WINDS WILL UNDER 10 KTS. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 26 29 26 29 / 0 0 0 0
ALW 27 30 27 30 / 0 0 0 0
PSC 29 31 29 31 / 0 0 0 0
YKM 26 29 27 29 / 0 0 0 0
HRI 28 31 28 31 / 0 0 0 0
ELN 27 30 26 30 / 0 0 0 0
RDM 25 29 25 29 / 0 0 0 0
LGD 24 31 24 31 / 0 0 0 0
GCD 27 35 28 35 / 0 0 0 0
DLS 31 36 30 36 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 4 PM PST SUNDAY FOR ORZ043-050-502-
505.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504-505.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR ORZ042-501-504.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
FREEZING FOG ADVISORY UNTIL 4 PM PST MONDAY FOR WAZ026-027-029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87/83/83
000
FXUS66 KPDT 171742 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
942 AM PST SAT JAN 17 2009
UPDATED AVIATION DISCUSSION.
.UPDATE...HAVE CANCELLED THE FREEZING FOG ADVISORY FOR THE LOWER
BASIN AREAS OF WASHINGTON AND OREGON. THE STRATUS DECK BASE HAS
LIFTED TO AROUND 2000 FEET WHICH IS ABOVE MOST SIGNIFICANT IMPACT
AREAS AND IS EXPECTED TO REMAIN THERE FOR THE REST OF THE DAY. ICY
ROADS WILL CONTINUE THERE AS THE DECK WILL REMAIN IN PLACE AND
PREVENT ANY SIGNIFICANT WARMING. OTHERWISE EXPECT LITTLE MOVEMENT
FROM THE DECK TODAY OTHER THAN SOME LIGHT EROSION AROUND THE
EDGES. CURRENT GRIDS HANDLE THIS WILL AND WOULD EXPECT THE ONLY
SIGNIFICANT UPDATE WILL BE TO THE ZONES THIS MORNING TO REMOVE THE
BASIN FOG HEADLINE.
EARLY THOUGHTS FOR THE AFTERNOON PACKAGE WILL LIKELY BE ANOTHER 24
HOUR EXTENSION TO THE REMAINING FREEZING FOG ADVISORY FOR THE
REMAINING AREAS. ALSO FEEL THAT WITH SOME ADDITIONAL LIGHT LIFTING
OF THE DECK THAT A FURTHER EXPANSION INTO THE REST OF CENTRAL AND
EAST CENTRAL OREGON AND POSSIBLY INTO LOWER VALLEYS OF THE BLUE
MOUNTAINS. AM NOT SEEING ANY SIGNIFICANT CHANGES TO THE UPPER
LEVEL PATTERN FOR THE NEXT FEW DAYS SO WILL CONTINUE THE
AIR STAGNATION ADVISORY AS IS AND MAY NEED TO PUSH IT INTO THE
UPPER JOHN DAY BASIN AREAS AS WELL. /JBONK
&&
AVIATION...18Z TAFS...HIGH PRESSURE WILL CONTINUE OVER THE AREA FOR
THE NEXT 24 HOURS WITH THE MAIN AVIATION CONCERN BEING THE CONTINUED
WIDESPREAD LOW STRATUS AND FOG BELOW 4000-4500 FT MSL. STRATUS DECK
BASE IS AT AROUND 2000 FT AND EXPECTED TO CONTINUE AT THAT LEVEL FOR
THE NEXT 24 HOURS. THIS WILL GIVE TAF LOCATIONS GENERALLY MVFR/IFR
CEILINGS AND VFR VISIBILITIES ALTHOUGH CEILINGS IN KALW AND KPDT MAY
DIP TO LIFR OVERNIGHT TONIGHT. KRDM WILL BE IN THE STRATUS LAYER AND
WILL SEE VLIFR/LIFR CEILINGS AND LIFR/IFR VISIBILITIES. WINDS WILL
REMAIN LIGHT AND GENERALLY UNDER 10 KTS. PERRY
&&
.PREV DISCUSSION... /ISSUED 300 AM PST SAT JAN 17 2009/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT...THE STRONG UPPER RIDGE
REMAINS OVER THE WESTERN U.S. EARLY THIS MORNING. THE AXIS OF THIS
RIDGE IS STILL BETWEEN 126W AND 127W. THE COMBINATION OF A WAVE
MOVING AROUND THE EAST AND SOUTH SIDES OF THE UPPER HIGH CENTER AND
THE PUSH OF AN UPPER TROUGH OVER THE EASTERN PACIFIC WILL CAUSE THIS
UPPER HIGH TO SHIFT EAST THROUGH THIS PERIOD. DESPITE THE SHIFT IN
THE UPPER RIDGE...WEATHER CONDITIONS ACROSS THE PACNW WILL REMAIN
UNCHANGED. THE LARGE AND EXPANDING AREA OF FOG AND STRATUS HAS
REACHED TO A TOP OF AROUND 3500 FEET MSL AND NOW EXTENDS FROM THE
COLUMBIA BASIN INTO CENTRAL OREGON. CLOUD BASES OF THIS STRATUS/FOG
AREA ARE ROUGHLY BETWEEN 1700 AND 2600 FEET MSL. THUS LOWEST
VISIBILITIES IN FREEZING FOG ARE AT LOCATIONS BETWEEN THESE BASE
LEVELS AND THE TOP OF THE STRATUS/FOG AREA. ALSO FOG/STRATUS IN
EAST-CENTRAL OREGON HAS DEEPENED TO TOP OUT AROUND 4000 FEET. AS A
RESULT IT HAS EXPANDED INTO THE GRANDE RONDE VALLY AND THE WALLOWA
VALLEY. LOW VISIBILITIES AND FREEZING FOG WITHIN THIS AREA RUNS FROM
ABOUT 3500 FEET TO AROUND 4000 FEET. BASED ON THE CURRENT BASES AND
TOPS OF THE FOG/STRATUS AREAS WILL KEEP CURRENT FREEZING FOG
ADVISORIES GOING...THOUGH FURTHER LIFTING OF THE BASES COULD RESULT
IN THE ADVISORIES IN THE LOWER COLUMBIA BASIN BEING DROPPED LATER
THIS MORNING. WILL SEE SOME BURN OFF ALONG THE FRINGES AGAIN THIS
AFTERNOON WITH THE FOG RETREATING FROM THE JOHN DAY BASIN AND FROM
AROUND THE BEND AREA. SHOULD ALSO SEE SOME BREAK UP IN THE GRANDE
RONDE VALLEY. WITH THE UPPER RIDGE OVERHEAD TONIGHT THROUGH SUNDAY
NIGHT SHOULD SEE THE CURRENT CONDITIONS PERSIST THROUGH THIS PERIOD.
90
LONG TERM...MONDAY THROUGH FRIDAY...A LARGE AND PERSISTENT HIGH
PRESSURE RIDGE ALOFT WILL CONTINUE TO DOMINATE THE AREA THROUGH
MONDAY AND TUESDAY. ALL OF THE LATEST MEDIUM TO EXTENDED RANGE
MODELS ARE INDICATING THAT THE UPPER RIDGE WILL BEGIN TO WEAKEN ON
WEDNESDAY AS WEATHER DISTURBANCES BEGIN TO PENETRATE IT FROM THE
PACIFIC. DESPITE THIS AGREEMENT THERE STILL REMAINS CONSIDERABLE IF
NOT SIGNIFICANT DIFFERENCES IN THE AMOUNT OF WEAKENING AND ALSO THE
PLACEMENT OF AN UPPER LOW THAT MOVES INTO THE SW US. REGARDLESS...
THE PATTERN BECOMES SPLIT WITH MOST OF THE ENERGY FROM WEATHER
SYSTEMS GOING WELL SOUTH OF THE FORECAST AREA WITH DRY CONDITIONS
REMAINING OVER THE PACIFIC NORTHWEST. BY THE END OF THE WEEK THE
FLOW ALOFT OVER THE REGION DOES BECOME MORE ZONAL W-NW BUT THERE
REMAINS A SPLIT FLOW WITH ADDITIONAL UPPER LOWS CUTTING UNDER THE
RIDGE INTO THE SW US. HAVE DECIDED TO KEEP FORECAST DRY...EXCEPT
PERHAPS THE CASCADE CREST AND THE CENTRAL/NORTHEAST MOUNTAINS WHICH
MAY SEE SOME VERY LIGHT PRECIP AS WEATHER SYSTEMS TRY WEAKEN THE
UPPER RIDGE. MUCH ABOVE NORMAL TEMPERATURES WILL PERSIST IN THE
MOUNTAINS WITH WIDESPREAD AREAS OF FOG AND STRATUS OVER THE LOWER
COLUMBIA BASIN AND ADJACENT VALLEYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 29 26 29 26 / 0 0 0 0
ALW 30 27 30 27 / 0 0 0 0
PSC 33 29 33 29 / 0 0 0 0
YKM 31 27 31 27 / 0 0 0 0
HRI 31 28 31 28 / 0 0 0 0
ELN 30 26 30 26 / 0 0 0 0
RDM 32 25 32 25 / 0 0 0 0
LGD 35 23 36 24 / 0 0 0 0
GCD 46 28 44 28 / 0 0 0 0
DLS 35 30 35 30 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FREEZING FOG ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR ORZ042-
043-050-501-504.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR ORZ041>044-
501-504.
WA...FREEZING FOG ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR WAZ026-
027-029.
AIR STAGNATION ADVISORY UNTIL 4 PM PST TUESDAY FOR WAZ024-
026>029.
&&
$$
TI:GGG
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
87
| 
