000
FXUS65 KFGZ 201624
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
920 AM MST TUE JAN 20 2009

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO PRODUCE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TODAY AND WEDNESDAY. BY THURSDAY AND
FRIDAY...A MOIST PACIFIC STORM SYSTEM WILL BRING RAIN AND HIGH
ELEVATION SNOW ALONG WITH MUCH COOLER TEMPERATURES. UNSETTLED
WEATHER WILL CONTINUE INTO EARLY NEXT WEEK.

&&
.DISCUSSION...HIGH CLOUDS ARE STREAMING ACROSS NORTHERN ARIZONA FROM
THE SOUTH AS A TROUGH OF LOW PRESSURE DEEPENS OFF THE WEST COAST.
THE HIGH AMPLITUDE RIDGE OF HIGH PRESSURE THAT HAS BEEN OVER THE
AREA FOR WELL OVER A WEEK WILL WEAKEN TODAY AND TOMORROW...BUT
TEMPERATURES WILL CONTINUE TO BE ABOVE SEASONAL NORMALS IN MOST
LOCATIONS WITH DRY CONDITIONS CONTINUING.

BEGINNING LATE WEDNESDAY...THE SOUTHERLY BRANCH OF THE WESTERLIES
WILL UNDERCUT THE HIGHLY AMPLIFIED WEST COAST RIDGE BRINGING A
SERIES OF MINOR S/W TROUGHS ACROSS THE SOUTHWESTERN STATES. CURRENT
FORECAST HAS SHORT-TERM TRENDS AND NO UPDATES EXPECTED. MODELS
BECOMING A LITTLE MORE CONSISTENT WITH UPCOMING END OF THE WEEK
SYSTEM...AND WILL BE MAKING SOME ADJUSTMENTS TO POP VALUES AND
TIMING OF SYSTEMS IN AFTERNOON PACKAGE ONCE COMPLETE MODEL GUIDANCE
IS IN.

.PREV DISCUSSION /230 AM MST/....THE FIRST SYSTEM WILL MOVE ACROSS
THE AREA ON THURSDAY. MODELS HAVE HAD DIFFICULTIES WITH THE TIMING
AND EVOLUTION OF THIS SYSTEM AND EVEN NOW SHOW TIMING AND AMPLITUDE
DIFFERENCES BETWEEN THE GFS...ECMWF...AND NAM. ON THE OTHER
HAND...ALL THREE MODELS ARE IN AGREEMENT THAT THIS WILL BE A
WEAKENING SYSTEM AS IT MOVES ONSHORE. BOTH SYNOPTIC-SCALE FORCING
AND OROGRAPHICS WILL BE WEAK. ISENTROPIC ANALYSIS INDICATES ONLY
WEAK UPWARD MOTION AS WELL. HOWEVER...PWAT IMAGERY SHOWS A
SUBSTANTIAL PLUME OF SUBTROPICAL MOISTURE MOVING NORTHWARD THAT WILL
BE INGESTED BY THIS SYSTEM AS IT MOVES ACROSS THE SOUTHWEST.
THUS...EXPECT A PERIOD FROM LATE WEDNESDAY NIGHT THROUGH EARLY
FRIDAY MORNING WITH GENERALLY LIGHT PCPN. AT THIS TIME...PCPN
AMOUNTS OF UP TO 1/4 INCH OVER THE LOWER ELEVATIONS WITH UP TO 1/2
INCH OVER THE HIGHER TERRAIN APPEAR LIKELY.

SNOW LEVELS WILL BE VERY HIGH SINCE THIS IS A WARM SUBTROPICAL
MOISTURE PLUME. EXPECT SNOW LEVELS ABOVE 9000 FEET WEDNESDAY NIGHT...
FALLING TO AROUND 8500 FEET THURSDAY MORNING...AND AROUND 8000 FEET
BY THURSDAY NIGHT. SNOW LEVELS WILL FALL TO AROUND 7500 FEET BY
FRIDAY MORNING BUT MOST OF THE PCPN WILL HAVE ALREADY ENDED BY THAT
TIME.

WEAK RIDGING BEGINS TO BUILD ACROSS THE AREA LATE FRIDAY INTO
SATURDAY ALLOWING TEMPS TO RECOVER A FEW DEGREES. THE NEXT SYSTEM
WILL ARRIVE ON SUNDAY BUT MODEL DIFFERENCES REMAIN LARGE AT THIS
TIME. MODELS SUGGEST LONG-WAVE TROUGHING WILL DEVELOP ACROSS THE
WEST BRINGING AN EXTENDED PERIOD OF UNSETTLED AND COOL WEATHER TO THE
SOUTHWEST. CURRENT FCST PACKAGE HAS CHANCES OF PCPN INCREASING ON
MONDAY AND TUESDAY WITH A DRYING TREND BEGINNING ON WEDNESDAY.


&&

.AVIATION...FOR THE 18Z PACKAGE...EXPECT NORTHEASTERLY DAYTIME WINDS
AT 5-15 KTS AND VFR CONDITIONS FOR THE NEXT 24 HOURS. SCT-BKN CIRRUS
WILL BE INCREASING FROM SOUTHWEST TO NORTHEAST ACROSS THIS
AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................STAUDENMAIER
AVIATION/FIRE WEATHER......41

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 200918
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 AM MST TUE JAN 20 2009

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO PRODUCE SEASONABLE
TEMPERATURES AND DRY CONDITIONS TODAY AND WEDNESDAY. BY THURSDAY AND
FRIDAY...A MOIST PACIFIC STORM SYSTEM WILL BRING RAIN AND HIGH
ELEVATION SNOW ALONG WITH MUCH COOLER TEMPERATURES. UNSETTLED
WEATHER WILL CONTINUE INTO EARLY NEXT WEEK.

&&

.DISCUSSION...THE PERSISTENT DEEP TROUGH OVER THE EASTERN HALF OF
THE NATION AND STRONG RIDGE OVER THE WEST WILL REMAIN IN PLACE TODAY
AND WEDNESDAY. EXPECT NEAR TO ABOVE NORMAL DAYTIME TEMPS TODAY AND
TOMORROW ALONG WITH LIGHT WINDS.

BEGINNING LATE WEDNESDAY...THE PATTERN WILL UNDERGO SOME CHANGES. THE
SOUTHERLY BRANCH OF THE WESTERLIES WILL UNDERCUT THE HIGHLY AMPLIFIED
WEST COAST RIDGE BRINGING A SERIES OF MINOR S/W TROUGHS ACROSS THE
SOUTHWESTERN STATES.

THE FIRST SYSTEM WILL MOVE ACROSS THE AREA ON THURSDAY. MODELS HAVE
HAD DIFFICULTIES WITH THE TIMING AND EVOLUTION OF THIS SYSTEM AND
EVEN NOW SHOW TIMING AND AMPLITUDE DIFFERENCES BETWEEN THE GFS...
ECMWF...AND NAM. ON THE OTHER HAND...ALL THREE MODELS ARE IN
AGREEMENT THAT THIS WILL BE A WEAKENING SYSTEM AS IT MOVES ONSHORE.
BOTH SYNOPTIC-SCALE FORCING AND OROGRAPHICS WILL BE WEAK. ISENTROPIC
ANALYSIS INDICATES ONLY WEAK UPWARD MOTION AS WELL. HOWEVER...PWAT
IMAGERY SHOWS A SUBSTANTIAL PLUME OF SUBTROPICAL MOISTURE MOVING
NORTHWARD THAT WILL BE INGESTED BY THIS SYSTEM AS IT MOVES ACROSS
THE SOUTHWEST. THUS...EXPECT A PERIOD FROM LATE WEDNESDAY NIGHT
THROUGH EARLY FRIDAY MORNING WITH GENERALLY LIGHT PCPN. AT THIS
TIME...PCPN AMOUNTS OF UP TO 1/4 INCH OVER THE LOWER ELEVATIONS WITH
UP TO 1/2 INCH OVER THE HIGHER TERRAIN APPEAR LIKELY.

SNOW LEVELS WILL BE VERY HIGH SINCE THIS IS A WARM SUBTROPICAL
MOISTURE PLUME. EXPECT SNOW LEVELS ABOVE 9000 FEET WEDNESDAY NIGHT...
FALLING TO AROUND 8500 FEET THURSDAY MORNING...AND AROUND 8000 FEET
BY THURSDAY NIGHT. SNOW LEVELS WILL FALL TO AROUND 7500 FEET BY
FRIDAY MORNING BUT MOST OF THE PCPN WILL HAVE ALREADY ENDED BY THAT
TIME.

WEAK RIDGING BEGINS TO BUILD ACROSS THE AREA LATE FRIDAY INTO
SATURDAY ALLOWING TEMPS TO RECOVER A FEW DEGREES. THE NEXT SYSTEM
WILL ARRIVE ON SUNDAY BUT MODEL DIFFERENCES REMAIN LARGE AT THIS
TIME. MODELS SUGGEST LONG-WAVE TROUGHING WILL DEVELOP ACROSS THE
WEST BRINGING AN EXTENDED PERIOD OF UNSETTLED AND COOL WEATHER TO THE
SOUTHWEST. CURRENT FCST PACKAGE HAS CHANCES OF PCPN INCREASING ON
MONDAY AND TUESDAY WITH A DRYING TREND BEGINNING ON WEDNESDAY.


&&

.AVIATION...FOR THE 12Z PACKAGE...EXPECT GENERALLY LIGHT
NORTHEASTERLY DAYTIME WINDS AND VFR CONDITIONS FOR THE NEXT 24
HOURS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................DB
AVIATION/FIRE WEATHER......KD

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 200407
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST MON JAN 19 2009

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO PRODUCE SEASONABLE
TEMPERATURES AND DRY CONDITIONS ON TUESDAY. STARTING WEDNESDAY...THE
FIRST IN A SERIES OF PACIFIC WEATHER SYSTEMS WILL BRING INCREASING
CLOUDS. BY THURSDAY AND FRIDAY...EXPECT COOLER TEMPERATURES WITH A
CHANCE OF SHOWERS...MAINLY IN THE FORM OF RAIN. UNSETTLED WEATHER WILL
CONTINUE INTO EARLY NEXT WEEK.

&&

.DISCUSSION...HIGH PRESSURE WILL BRING MILD AND DRY WEATHER TO
THE NORTHLAND THROUGH TUESDAY. BY WEDNESDAY...CLOUDS WILL BE ON THE
INCREASE...AS A WEAK LOW PRESSURE SYSTEM MOVES TOWARD ARIZONA. ON
THURSDAY AND FRIDAY EXPECT COOLER TEMPERATURES WITH A CHANCE OF
SHOWERS...PRIMARILY IN THE FORM OF RAIN...AS THE LOW MOVES ACROSS
THE STATE. THE AIR MASS WITH THIS LOW WILL BE RELATIVELY MILD SO SNOW
LEVELS WILL RANGE FROM 7500-8500 FEET WITH ACCUMULATING SNOW ONLY
OVER THE HIGHEST MOUNTAINS. THE LOW WILL BE WEAK BUT FAIRLY MOIST SO
EXPECTING RAINFALL AMOUNTS FROM THURSDAY INTO FRIDAY RANGING FORM
0.10 TO 0.50 INCHES. LATE ON FRIDAY...SKIES WILL BEGIN TO CLEAR AND
CHANCES FOR PRECIPITATION WILL DIMINISH AS THE SYSTEM MOVES TO THE
EAST. ANOTHER WEAK WEATHER DISTURBANCES WILL BRUSH NORTHERN ARIZONA
ON SATURDAY BUT ONLY A SLIGHT CHANCE OF SHOWERS IS EXPECTED WITH
BELOW NORMAL TEMPERATURES AND BREEZY WINDS BEING THE MAIN IMPACT.

FOR SUNDAY AND BEYOND...MODELS AGREE THAT A SERIES OF WEATHER
DISTURBANCES WILL BRING UNSETTLED WEATHER CONDITIONS TO NORTHERN
ARIZONA BUT NO MAJOR STORMS ON THE HORIZON AS OF YET.

&&

.AVIATION...FOR THE 06Z PACKAGE...EXPECT VFR CONDITIONS UNDER VARIABLE
HIGH CLOUDS AND LIGHT WINDS OVER THE NEXT 24 HOURS. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................MCCOLLUM
AVIATION/FIRE WEATHER......MCCOLLUM

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 192218
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
315 PM MST MON JAN 19 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING SLIGHTLY ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH TUESDAY. WEATHER CONDITIONS
WILL CHANGE STARTING WEDNESDAY AS THE HIGH PRESSURE RIDGE BEGINS TO
BREAKDOWN...OPENING THE DOOR FOR A SERIES OF PACIFIC STORM SYSTEMS.
CHANCES FOR PRECIPITATION WILL INCREASE BY LATE WEDNESDAY...AND WILL
CONTINUE THROUGH AT LEAST FRIDAY MORNING. A SLIGHT BREAK IN THE
ACTION IS EXPECTED ON SATURDAY WITH ONLY SLIGHT CHANCES FOR
PRECIPITATION.

&&

.DISCUSSION...HIGH PRESSURE WILL PRODUCE MILD AND DRY WEATHER
CONDITIONS ACROSS THE NORTHLAND THROUGH TUESDAY. BY WEDNESDAY THE
HIGH PRESSURE RIDGE WILL BREAKDOWN AND A WEAK LOW PRESSURE SYSTEM
WILL MOVE TOWARDS ARIZONA INCREASING CLOUDS AND CHANCES FOR
PRECIPITATION STARTING LATE WEDNESDAY. THE CENTER OF THE LOW WILL BE
FILLING AS IT MOVES ACROSS UTAH ON THURSDAY AND THE AIRMASS WILL
LIKELY NOT BE COLD ENOUGH TO PRODUCE MUCH SNOWFALL BELOW 8000 FEET.
BOTH THE DYNAMICS AND OROGRAPHICS WITH THIS FILLING LOW ARE WEAK AND
SO WE ARE EXPECTING ONLY LIGHT RAINFALL AMOUNTS...WITH UP TO A
QUARTER INCH OF RAINFALL IN THE HIGH COUNTRY. ON FRIDAY...SKIES WILL
BEGIN TO CLEAR AND CHANCES FOR PRECIPITATION WILL DIMINISH AS THE
SYSTEM MOVES EASTWARD AWAY FROM ARIZONA. EXPECT A SLIGHT BREAK
BETWEEN SYSTEMS ON SATURDAY WITH ONLY SLIGHT CHANCES FOR
PRECIPITATION AS A WEAK RIDGE MOVES THROUGH THE UPPER LEVEL PATTERN.

THE GFS AND EUROPEAN MODELS APPEAR TO HAVE SETTLED ON A SOLUTION FOR
THE THURSDAY SYSTEM. THE 18/12Z RUN FROM BOTH MODELS TRACK THE
SYSTEM A BIT FURTHER NORTH INTO UTAH. FORECAST CONFIDENCE IS NOW
FAIR THAT NORTHERN ARIZONA WILL SEE A LIGHT RAIN EVENT WITH SNOW
LEVELS ABOVE 8000 FEET.

SUNDAY AND BEYOND...ANOTHER SYSTEM MAY MOVE THROUGH THE SOUTHWEST ON
MONDAY...HOWEVER THE DETAILS REMAIN SKETCHY AT THIS POINT. WE HAVE
INCREASED CHANCES FOR PRECIPITATION LATE SUNDAY INTO MONDAY...
ALTHOUGH THE TRACK AND THE INTENSITY OF THIS NEXT SYSTEM ARE STILL
SUBJECT TO LARGE CHANGES. STAY TUNED FOR ADDITIONAL DETAILS AS THE
TIME PERIOD GETS CLOSER.

&&

.AVIATION...FOR THE 00Z PACKAGE...EXPECT GENERALLY LIGHT EASTERLY
WINDS SHIFTING TO THE SOUTHEAST TUESDAY WITH SCT HIGH CLOUDS THROUGH
THE PERIOD. VFR CONDITIONS CAN BE EXPECTED. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................BOHLIN
AVIATION/FIRE WEATHER......TC

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 190954
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
255 AM MST MON JAN 19 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING SLIGHTLY ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF THIS WEEK.
HIGH PRESSURE WILL BEGIN TO BREAK DOWN BY WEDNESDAY...OPENING THE
DOOR FOR A ROUND OF PACIFIC STORM SYSTEMS. CHANCES FOR PRECIPITATION
WILL INCREASE BY LATE WEDNESDAY...AND WILL CONTINUE THROUGH AT LEAST
FRIDAY MORNING.

&&

.DISCUSSION...HIGH PRESSURE TO OUR NORTH WILL SLOWLY WEAKEN OVER THE
NEXT FEW DAYS AS SOUTHERN STREAM ENERGY BEGINS TO UNDERCUT THE WEST
COAST RIDGE. LIGHT EASTERLY FLOW IN THE BOUNDARY LAYER WILL CONTINUE
TO KEEP THE NORTHERN HALF OF THE MOGOLLON RIM COOL TODAY...ALL OTHER
AREAS WILL BE AT LEAST AS WARM AS SUNDAY.

THE FLOW BECOMES SOUTHERLY BY TUESDAY AND WEDNESDAY AS THE FIRST
SOUTHERN STREAM SYSTEM MOVES SLOWLY TOWARD CALIFORNIA. CLOUD COVER
WILL INCREASE FROM SOUTH TO NORTH...BUT TEMPERATURES WILL REMAIN
MILD AS HGHTS ARE STUBBORN TO FALL.

AT THIS POINT...THE PICTURE BECOMES RATHER UNCLEAR. MODELS ARE
STILL ALL OVER THE PLACE WITH THE STRENGTH AND THE TIMING OF THE
FIRST SOUTHERN STREAM SYSTEM. OUR BEST GUESS IS SOMETIME LATE
WEDNESDAY THROUGH EARLY FRIDAY. SNOW LEVELS WILL LIKELY BE HIGH WITH
MOST AREAS SEEING RAIN. QPF AMOUNTS ARE HIGHLY VARIABLE AND WILL
DEPEND ON THE FINAL SOLUTION...IT IS TOO EARLY TO TELL.

FOR NEXT WEEKEND...MODELS REMAIN UNCLEAR STILL WITH MANY DIFFERENT
SOLUTIONS AVAILABLE. THE BEST SCENARIO AT THIS TIME WILL BE TO KEEP
COOLER TEMPERATURES AND CHANCE POPS IN ALL DAYS THROUGH NEXT MONDAY
AS THE SOUTHERN STREAM MAY BECOME MORE ACTIVE. WE MAY EVEN
TRANSITION INTO A WEST COAST TROUGH BY DAY SEVEN OR EIGHT...TIME
WILL TELL ON THIS...SPECIFICS IN THE MODEL DATA SHOULD BE REGARDED
SOMEWHAT LIGHTLY AT THIS TIME.

&&

.AVIATION...FOR THE 12Z PACKAGE...EXPECT GENERALLY LIGHT EAST TO
NORTHEAST WINDS AND SCT-BKN HIGH CLOUDS FOR THE NEXT 24 HOURS. VFR
CONDITIONS ARE EXPECTED FOR THE PERIOD. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................PETERSON
AVIATION/FIRE WEATHER......DJO

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 190334
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
825 PM MST SUN JAN 18 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING SLIGHTLY ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF THIS WEEK.
THE RIDGE WILL BEGIN TO BREAK DOWN BY WEDNESDAY...OPENING THE DOOR
FOR A ROUND OF PACIFIC STORM SYSTEMS. THE NEXT CHANCE FOR
PRECIPITATION WILL BEGIN WEDNESDAY EVENING AND CONTINUE THROUGH
FRIDAY MORNING.

&&

.DISCUSSION...SOME MID AND HIGH LEVEL MOISTURE IS MOVING INTO THE
AREA FROM THE SOUTHWEST. OUR WEATHER WILL CONTINUE TO REMAIN QUIET
TONIGHT AND TOMORROW AS A HIGH AMPLITUDE RIDGE SITS OVER THE WESTERN
UNITED STATES. THE GRID PACKAGE LOOKS GOOD FOR THE NIGHT TIME HOURS
WITH NO CHANGES PLANNED.

.PREVIOUS DISCUSSION (310 PM MST)...HIGH PRESSURE WILL CONTINUE TO
PRODUCE A MILD DRY AIRMASS OVER THE REGION THROUGH TUESDAY. ON
WEDNESDAY...THE RIDGE OF HIGH PRESSURE IS EXPECTED TO BREAK DOWN AND
A SPLIT JET FLOW PATTERN WILL DEVELOP ACROSS THE EASTERN PACIFIC.
THE SOUTHERN BRANCH OF THE JET WILL PUSH A SERIES OF WEAK LOW
PRESSURE SYSTEMS ACROSS THE SOUTHWEST FROM WEDNESDAY ONWARD. THE
NEXT LOW PRESSURE SYSTEM IS FORECAST TO MOVE INTO ARIZONA ON
THURSDAY WITH INCREASING CHANCES FOR PRECIPITATION FOR THE LATTER
HALF OF THE WORK WEEK.

BOTH THE GFS AND EUROPEAN MODELS ARE PROVIDING HIGHLY INCONSISTENT
SOLUTIONS...EVEN RUN TO RUN CONSISTENCY IS POOR. FOR EXAMPLE...THE
18/12Z EUROPEAN MODEL RUN SOLUTION FOR THE THURSDAY SYSTEM MOVES THE
CENTER OF THE LOW 300 MILES FURTHER NORTH THAN THE PREVIOUS 18/00Z
RUN. THE GOOD NEWS IS THE DIFFERENCES BETWEEN THE GFS AND EUROPEAN
MODELS APPEAR TO BE DECREASING OVER TIME FOR THE THURSDAY SOLUTION
WITH THE GFS FORECAST TRACK RUNNING 6 HOURS AHEAD OF THE EUROPEAN.

WEDNESDAY THROUGH FRIDAY...DESPITE THESE FORECAST MODEL ISSUES WE
HAVE DECIDED TO INCREASE THE CHANCES FOR PRECIPITATION FOR LATE
WEDNESDAY INTO EARLY FRIDAY...AS PRECIPITATION IS LIKELY TO OCCUR
DURING THIS PERIOD. THE MAIN FORECAST CHALLENGES AT THIS POINT ARE
HOW COLD WILL THE AIRMASS BE OVER THE NORTHLAND...HOW LOW WILL THE
SNOW LEVELS DROP AND HOW MUCH PRECIPITATION WILL OCCUR AS TROPICAL
MOISTURE IS INJECTED INTO THE SYSTEM. THESE ANSWERS WILL DEPEND
MAINLY ON HOW THE LOW TRACKS AND ADDITIONAL DETAILS WILL BE ADDED TO
THE FORECAST AS CONFIDENCE IMPROVES IN THE TRACK.

SATURDAY AND BEYOND...A BRIEF BREAK BETWEEN SYSTEM IS FORECAST FOR
SATURDAY WITH VERY LOW CHANCES FOR PRECIPITATION. HOWEVER...FORECAST
CONFIDENCE BEYOND THURSDAY IS EXTREMELY LOW DUE TO THE SPLIT FLOW
PATTERN AND THE LARGE FORECAST GUIDANCE INCONSISTENCIES.

&&

.AVIATION...FOR THE 06Z PACKAGE...VFR CONDITIONS EXPECTED FOR THE
NEXT 24 HRS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................42
AVIATION/FIRE WEATHER......42

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 182215
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
310 PM MST SUN JAN 18 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING SLIGHTLY ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF NEXT WEEK.
HIGH PRESSURE WILL BEGIN TO BREAK DOWN BY WEDNESDAY...OPENING THE
DOOR FOR ANOTHER ROUND OF PACIFIC STORM SYSTEMS. THE NEXT CHANCE FOR
PRECIPITATION WILL BEGIN WEDNESDAY EVENING AND CONTINUE THROUGH
FRIDAY MORNING.

&&

.DISCUSSION...HIGH PRESSURE WILL CONTINUE TO PRODUCE A MILD DRY
AIRMASS OVER THE REGION THROUGH TUESDAY. ON WEDNESDAY...THE RIDGE OF
HIGH PRESSURE IS EXPECTED TO BREAK DOWN AND A SPLIT JET FLOW PATTERN
WILL DEVELOP ACROSS THE EASTERN PACIFIC. THE SOUTHERN BRANCH OF THE
JET WILL PUSH A SERIES OF WEAK LOW PRESSURE SYSTEMS ACROSS THE
SOUTHWEST FROM WEDNESDAY ONWARD. THE NEXT LOW PRESSURE SYSTEM IS
FORECAST TO MOVE INTO ARIZONA ON THURSDAY WITH INCREASING CHANCES
FOR PRECIPITATION FOR THE LATTER HALF OF THE WORK WEEK.

BOTH THE GFS AND EUROPEAN MODELS ARE PROVIDING HIGHLY INCONSISTENT
SOLUTIONS...EVEN RUN TO RUN CONSISTENCY IS POOR. FOR EXAMPLE...THE
18/12Z EUROPEAN MODEL RUN SOLUTION FOR THE THURSDAY SYSTEM MOVES THE
CENTER OF THE LOW 300 MILES FURTHER NORTH THAN THE PREVIOUS 18/00Z
RUN. THE GOOD NEWS IS THE DIFFERENCES BETWEEN THE GFS AND EUROPEAN
MODELS APPEAR TO BE DECREASING OVER TIME FOR THE THURSDAY SOLUTION
WITH THE GFS FORECAST TRACK RUNNING 6 HOURS AHEAD OF THE EUROPEAN.

WEDNESDAY THROUGH FRIDAY...DESPITE THESE FORECAST MODEL ISSUES WE
HAVE DECIDED TO INCREASE THE CHANCES FOR PRECIPITATION FOR LATE
WEDNESDAY INTO EARLY FRIDAY...AS PRECIPITATION IS LIKELY TO OCCUR
DURING THIS PERIOD. THE MAIN FORECAST CHALLENGES AT THIS POINT ARE
HOW COLD WILL THE AIRMASS BE OVER THE NORTHLAND...HOW LOW WILL THE
SNOW LEVELS DROP AND HOW MUCH PRECIPITATION WILL OCCUR AS TROPICAL
MOISTURE IS INJECTED INTO THE SYSTEM. THESE ANSWERS WILL DEPEND
MAINLY ON HOW THE LOW TRACKS AND ADDITIONAL DETAILS WILL BE ADDED TO
THE FORECAST AS CONFIDENCE IMPROVES IN THE TRACK.

SATURDAY AND BEYOND...A BRIEF BREAK BETWEEN SYSTEM IS FORECAST FOR
SATURDAY WITH VERY LOW CHANCES FOR PRECIPITATION. HOWEVER...FORECAST
CONFIDENCE BEYOND THURSDAY IS EXTREMELY LOW DUE TO THE SPLIT FLOW
PATTERN AND THE LARGE FORECAST GUIDANCE INCONSISTENCIES.

&&

.AVIATION...FOR THE 00Z PACKAGE...VFR CONDITIONS EXPECTED FOR THE
NEXT 24 HRS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................BOHLIN
AVIATION/FIRE WEATHER......DB

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 181608
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
905 AM MST SUN JAN 18 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING SLIGHTLY ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF NEXT WEEK.
HIGH PRESSURE WILL BEGIN TO BREAK DOWN BY WEDNESDAY...OPENING THE
DOOR FOR ANOTHER ROUND OF PACIFIC STORM SYSTEMS...AND INCREASING
OUR CHANCES FOR PRECIPITATION.

&&

.DISCUSSION...HIGH PRESSURE WILL CONTINUE THROUGH EARLY NEXT WEEK
WITH OCCASIONAL PERIODS OF CIRRUS CLOUDS MOVING ACROSS THE
SOUTHWEST. NIGHT SHIFT FORECAST GRIDS ARE GOOD NO UPDATES PLANNED.

&&

. PREV DISCUSSION 335 AM...THE SHORT TERM STILL FEATURES SEVERAL
DAYS OF HIGH PRESSURE WITH LIGHT EASTERLY FLOW IN THE BOUNDARY
LAYER. BY LATE TUESDAY OR WEDNESDAY...THE RIDGE WILL BE UNDERCUT BY
THE SOUTHERN STREAM...AND SOME MOISTURE MAY MOVE INTO ARIZONA. AN
EVEN STORMIER PATTERN MAY THEN MATERIALIZE BY THE WEEKEND. DETAILS
ARE STILL HIGHLY VARIABLE AT BEST...AND CONFIDENCE IN ANY ONE
SOLUTION IS LOW. THEREFORE...WE ARE FORCED TO CONTINUE
LOW-PROBABILITY POPS WITH A GRADUALLY COOING TREND FOR THE MIDDLE
AND LATTER PARTS OF THE WEEK. NOTHING EXISTS YET THAT WE CAN SINGLE
OUT...HOPEFULLY...THINGS WILL BECOME MORE CLEAR IN A DAY OR TWO.

&&

.AVIATION...FOR THE 18Z PACKAGE...VFR CONDITIONS EXPECTED FOR THE
NEXT 24 HRS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................BOHLIN
AVIATION/FIRE WEATHER......DB

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 181037
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
335 AM MST SUN JAN 18 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING SLIGHTLY ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF NEXT WEEK.
HIGH PRESSURE WILL BEGIN TO BREAK DOWN BY WEDNESDAY...OPENING THE
DOOR FOR ANOTHER ROUND OF PACIFIC STORM SYSTEMS...AND INCREASING
OUR CHANCES FOR PRECIPITATION.

&&

.DISCUSSION...THE SHORT TERM STILL FEATURES SEVERAL DAYS OF HIGH
PRESSURE WITH LIGHT EASTERLY FLOW IN THE BOUNDARY LAYER. BY LATE
TUESDAY OR WEDNESDAY...THE RIDGE WILL BE UNDERCUT BY THE SOUTHERN
STREAM...AND SOME MOISTURE MAY MOVE INTO ARIZONA. AN EVEN STORMIER
PATTERN MAY THEN MATERIALIZE BY THE WEEKEND. DETAILS ARE STILL
HIGHLY VARIABLE AT BEST...AND CONFIDENCE IN ANY ONE SOLUTION IS LOW.
THEREFORE...WE ARE FORCED TO CONTINUE LOW-PROBABILITY POPS WITH A
GRADUALLY COOING TREND FOR THE MIDDLE AND LATTER PARTS OF THE WEEK.
NOTHING EXISTS YET THAT WE CAN SINGLE OUT...HOPEFULLY...THINGS WILL
BECOME MORE CLEAR IN A DAY OR TWO.

&&

.AVIATION...FOR THE 12Z PACKAGE...VFR CONDITIONS EXPECTED FOR THE
NEXT 24 HRS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....................PETERSON
AVIATION/FIRE WEATHER......DJO

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 180356
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST SAT JAN 17 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF NEXT WEEK.
THE HIGH PRESSURE RIDGE IS FORECAST TO BREAK DOWN BY
WEDNESDAY...OPENING THE DOOR FOR ANOTHER ROUND OF PACIFIC STORMS
SYSTEM AND INCREASING OUR CHANCES FOR PRECIPITATION.

&&

.DISCUSSION...HIGH PRESSURE ALOFT HAS BEEN KEEPING THE WEATHER QUIET
ACROSS NORTHERN ARIZONA THIS EVENING...AND THAT TREND WILL CONTINUE
FOR THE NEXT SEVERAL DAYS. LIGHT WINDS AND MAINLY SUNNY SKIES WILL
RESULT FOR THE NEXT SEVERAL DAYS. FOR NOW...A REVIEW OF THIS EVENING
GRID PACKAGE LOOK GOOD TO GO. NO CHANGES ARE PLANNED.

.PREVIOUS DISCUSSION (330 PM MST)...THE HIGH PRESSURE RIDGE WILL
REMAIN IN PLACE ACROSS THE WESTERN U.S. WITH WARM AND DRY CONDITIONS
PERSISTING THROUGH THE EARLY PART OF NEXT WEEK. THE GFS AND EUROPEAN
MODELS CONTINUE TO AGREE THAT THIS RIDGE WILL BREAK DOWN BY MID WEEK
AND BOTH MODELS SHOW A SPLIT DEVELOPING IN THE JET STREAM ACROSS THE
EASTERN PACIFIC.

WEDNESDAY THROUGH SUNDAY...A CHANGE IN THE UPPER LEVEL FLOW PATTERN
WILL LIKELY CAUSE TEMPERATURES TO DROP SIGNIFICANTLY. THE SPLIT JET
PATTERN WILL ALSO SEND A SERIES OF WEAK LOW PRESSURE SYSTEMS ACROSS
THE SOUTHWEST INCREASING OUR CHANCES FOR RAIN AND HIGH ELEVATION
SNOW SHOWERS. THE FORECAST CHALLENGE AT THIS POINT IS THAT COMPUTER
MODEL SOLUTIONS DIVERGE FROM THURSDAY ONWARD AND THE RUN TO RUN
CONSISTENCY IS POOR. THIS MEANS FORECASTER CONFIDENCE BEYOND
WEDNESDAY IS LOW AND AS A RESULT THE WEATHER DETAILS MUST REMAIN
SKETCHY WITH LOW CHANCES FOR PRECIPITATION FROM WEDNESDAY THROUGH
NEXT SUNDAY. THE FORECASTER CONSENSUS IS TO KEEP THE FORECAST GRIDS
MORE IN LINE WITH THE EUROPEAN MODEL AS THIS MODEL HAS PROVE TO BE
MORE ACCURATE THAN THE GFS IN THE EXTENDED PERIOD. FORECAST UPDATES
FROM THURSDAY ONWARD WILL LIKELY BE NEEDED OVER THE NEXT FEW
DAYS...AS THE TIMING GETS CLOSER AND OUR FORECAST GUIDANCE IMPROVES.
STAY TUNED.

&&

.AVIATION...FOR THE 06Z PACKAGE...VFR CONDITIONS EXPECTED FOR THE
NEXT 24 HRS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&
$$

PUBLIC.....................42
AVIATION/FIRE WEATHER......42

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.

000
FXUS65 KFGZ 172232
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 PM MST SAT JAN 17 2009

.SYNOPSIS...HIGH PRESSURE WILL BRING ABOVE NORMAL DAYTIME
TEMPERATURES AND DRY CONDITIONS THROUGH THE EARLY PART OF NEXT WEEK.
THE HIGH PRESSURE RIDGE IS FORECAST TO BREAK DOWN BY
WEDNESDAY...OPENING THE DOOR FOR ANOTHER ROUND OF PACIFIC STORMS
SYSTEM AND INCREASING OUR CHANCES FOR PRECIPITATION.

&&

.DISCUSSION...THE HIGH PRESSURE RIDGE WILL REMAIN IN PLACE ACROSS
THE WESTERN U.S. WITH WARM AND DRY CONDITIONS PERSISTING THROUGH THE
EARLY PART OF NEXT WEEK. THE GFS AND EUROPEAN MODELS CONTINUE TO
AGREE THAT THIS RIDGE WILL BREAK DOWN BY MID WEEK AND BOTH MODELS
SHOW A SPLIT DEVELOPING IN THE JET STREAM ACROSS THE EASTERN
PACIFIC.

WEDNESDAY THROUGH SUNDAY...A CHANGE IN THE UPPER LEVEL FLOW PATTERN
WILL LIKELY CAUSE TEMPERATURES TO DROP SIGNIFICANTLY. THE SPLIT JET
PATTERN WILL ALSO SEND A SERIES OF WEAK LOW PRESSURE SYSTEMS ACROSS
THE SOUTHWEST INCREASING OUR CHANCES FOR RAIN AND HIGH ELEVATION
SNOW SHOWERS. THE FORECAST CHALLENGE AT THIS POINT IS THAT COMPUTER
MODEL SOLUTIONS DIVERGE FROM THURSDAY ONWARD AND THE RUN TO RUN
CONSISTENCY IS POOR. THIS MEANS FORECASTER CONFIDENCE BEYOND
WEDNESDAY IS LOW AND AS A RESULT THE WEATHER DETAILS MUST REMAIN
SKETCHY WITH LOW CHANCES FOR PRECIPITATION FROM WEDNESDAY THROUGH
NEXT SUNDAY. THE FORECASTER CONSENSUS IS TO KEEP THE FORECAST GRIDS
MORE IN LINE WITH THE EUROPEAN MODEL AS THIS MODEL HAS PROVEN TO BE
MORE ACCURATE THAN THE GFS IN THE EXTENDED PERIOD. FORECAST UPDATES
FROM THURSDAY ONWARD WILL LIKELY BE NEEDED OVER THE NEXT FEW
DAYS...AS THE TIMING GETS CLOSER AND OUR FORECAST GUIDANCE IMPROVES.
STAY TUNED.

&&



.AVIATION...FOR THE 00Z PACKAGE...VFR CONDITIONS EXPECTED FOR THE
NEXT 24 HRS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&
$$

PUBLIC.....................BOHLIN
AVIATION/FIRE WEATHER......DB

VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.