000
FXUS65 KLKN 152256
AFDLKN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ELKO NV
356 PM PDT MON SEP 15 2008

.SYNOPSIS...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH TOMORROW
MORNING...BRINGING CONTINUED DRY AND WARM WEATHER. A SERIES OF LOW
PRESSURE SYSTEMS WILL BRING A RISK FOR SHOWERS AND THUNDERSTORMS TO
THE GREAT BASIN REGION AREA BEGINNING LATE TOMORROW AND WEDNESDAY...
ALONG WITH COOLER TEMPERATURES. &&

.SHORT TERM...TONIGHT THROUGH WEDNESDAY. CLOUD-LESS SKIES PERSIST
OVER THE WESTERN UNITED STATES AT PRESENT. THE UPPER-LEVEL ANALYSIS
REVEALS A RIDGE CENTERED OVER NORTHERN UTAH...WITH A CLOSED LOW
SITTING WEST OF SAN FRANCISCO AND A TROUGH FURTHER WEST OVER THE
EASTERN PACIFIC. HOWEVER...AT LEAST THROUGH TOMORROW MORNING...THE
ONLY FEATURE IN OUR WEATHER IS THE RIDGE ALOFT WHICH WILL PROVIDE
CONTINUED MOSTLY CLEAR SKIES AND LIGHT WINDS.

TOMORROW AFTERNOON...THE SOUTHERLY FLOW ALOFT BETWEEN THE RIDGE TO
OUR EAST AND THE LOW TO OUR EAST WILL HELP PUMP SOME MONSOONAL
MOISTURE NORTHWARDS INTO THE REGION. HOWEVER...WE`RE STARTING TO
GET TO THE TIME OF YEAR WHERE WE NEED SOME UPPER-LEVEL FORCING TO GET
THINGS GOING AS THE SUN ANGLE DECREASES...SO ONLY VERY MINIMAL
THUNDERSTORM DEVELOPMENT IS EXPECTED MAINLY ALONG THE WESTERN FRINGES
OF THE CWA. WITH PW`S STILL PRETTY LOW...EXPECT THOSE FEW T-STORMS
THAT DO DEVELOP TO BE DRY...AND LOWERED POPS ACCORDINGLY. WITH THE
RIDGE STILL INFLUENCING OUR WEATHER AND THE SOUTHERLY FLOW ALOFT
KEEPING MID-LEVEL TEMPERATURES WARM...WE SHOULD HAVE NO PROBLEM
REACHING THE UPPER 80S IN MOST VALLEYS...WITH THE NORMALLY HOTTER
LOCATIONS PASSING 90. WINDS WILL BE A BIT STRONGER THAN DURING
RECENT DAYS...PARTICULARLY ACROSS NORTHERN NYE COUNTY WHERE
SOUTHERLY GUSTS MAY APPROACH 30 MPH DURING THE AFTERNOON.

ANY STORMS WILL DISSIPATE TOMORROW EVENING AS HEATING DISSIPATES...
BUT MOISTURE WILL CONTINUE STREAMING NORTHWARD...AND ACROSS THE
NORTHERN AND EASTERN PORTIONS OF THE CWA CLOUD COVER MAY ACTUALLY
INCREASE OVERNIGHT. THIS WILL HELP LOW TEMPERATURES STAY A BIT
MILDER THAN MANY RECENT NIGHTS. BY WEDNESDAY...THE CLOSED LOW WEST OF
SAN FRANCISCO WILL HAVE OPENED UP INTO A NEGATIVELY TILTED SHORT-WAVE
TROUGH...AND IT WILL BE APPROACHING OUR CWA. COMBINED WITH THE
CONTINUED MONSOONAL INFLUX ON THE SOUTHERLY WINDS...AND WE SHOULD
HAVE MUCH MORE WIDESPREAD SCATTERING OF ISOLATED SHOWERS AND
THUNDERSTORMS WEDNESDAY AFTERNOON. INSTABILITY WILL BE GREATLY
ENHANCED BY THE NEGATIVELY TILTED TROUGH AS IT APPROACHES...SO SOME
STORMS MAY GET GOING BY 10 OR 11AM ACROSS THE SOUTHWESTERN FRINGES OF
THE CWA. THE INFLUX OF MOISTURE AND RELATIVELY LOW WINDS ALOFT SHOULD
ALLOW STORMS OVER MUCH OF THE CWA TO TRANSITION TO WET...BUT ALONG
THE WESTERN FRINGES MOISTURE WILL ALREADY BE DIMINISHING BY AFTERNOON
AND STORMS MAY REMAIN DRY. HIGH TEMPERATURES WEDNESDAY WILL BE
SEVERAL DEGREES LOWER THAN THEY WILL BE TOMORROW...MAINLY DUE TO THE
INFLUX OF CLOUDS. RCM &&

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.  THE EXTENDED PERIOD
COULD BE A FAIRLY ACTIVE TIME. THE MODELS ARE NOT IN VERY GOOD
AGREEMENT...ESPECIALLY GOING INTO THE WEEKEND. WED NIGHT INTO THU
WILL SEE SOME LINGERING MONSOON MOISTURE ACROSS THE EASTERN CWA
WHICH COULD LEAD TO SOME SHOWERS AND THUNDERSTORMS. TEMPERATURES
WILL CONTINUE TO BE ABOVE NORMAL AS WARM AIR WILL REMAIN IN PLACE
WITH SOUTHERLY FLOW AHEAD OF A CUTOFF LOW MOVING IN FROM THE
PACIFIC. THIS CUTOFF LOW IS WHERE THERE IS GREAT DISCREPANCY IN THE
MODELS. ECMWF IS FURTHER NORTH AND MORE PROGRESSIVE THAN THE GFS.
THE GFS SOLUTION BRINGS UPPER LOW INTO SOUTHERN NV AND JUST SLOWLY
MOVES IT NE INTO THE EARLY PART OF NEXT WEEK. THE ECMWF BRINGS LOW
ACROSS NORTHERN NV AND HAS IT MOVING OUT OF AREA BY SUN. MOST OF THE
GFS ENSEMBLE MEMBERS SUPPORT MORE OF A ECMWF SOLUTION WHICH IS ALSO
SIMILAR TO THE CANADIAN SO WILL FOLLOW THIS SOLUTION GOING INTO THE
WEEKEND.

KEPT MENTION OF SHOWERS ACROSS MOST OF CWA FOR SAT WITH HIGHER POPS
ACROSS THE NORTHERN ZONES. TEMPERATURES WILL COOL OFF WITH SOME
AREAS POSSIBLY REMAINING IN THE 60S ACROSS THE NORTH WITH 70S
ELSEWHERE ON SAT. EXPECT A SHORTWAVE RIDGE TO MOVE ACROSS THE REGION
ON SUN WHICH WILL HELP TO WARM TEMPERATURES BACK UP A BIT BEFORE
ANOTHER STORM SYSTEM WITH A FAIRLY STRONG COLD FRONT MOVES IN FOR
MONDAY. TIMING OF THE FRONT MONDAY WILL BE CRITICAL TO THE
TEMPERATURE FORECAST. RIGHT NOW THE ECMWF DOES NOT HAVE FRONT
PASSING THROUGH SOUTHERN ZONES UNTIL MONDAY NIGHT WHICH COULD ALLOW
HIGHS TO GET INTO THE 80S SOUTH WITH JUST 70S AND POSSIBLY 60S
NORTH. RIGHT NOW DO NOT HAVE A REAL STRONG TEMPERATURE GRADIENT
ACROSS THE CWA AND WILL WAIT TO SEE IF THERE IS BETTER MODEL
CONSENSUS AND CONSISTENCY WITH TIMING ISSUES IN LATER RUNS. JMG &&

.AVIATION...UPPER LEVEL RIDGE WILL GRADUALLY MOVE EASTWARD OVER THE
NEXT 24 HOURS. THIS WILL KEEP SKIES MOSTLY CLEAR SKIES EAST AND SOME
CUMULUS BUILDUPS OVER THE WEST BY TUE AFTERNOON. WINDS WILL
GENERALLY REMAIN LIGHT THROUGH TUE MORNING AND THEN START TO TURN
MORE SOUTHERLY TUE AFTERNOON. JMG &&

.FIRE WEATHER...HIGH PRESSURE WILL KEEP DRY CONDITIONS AND LIGHT
WINDS PREVALENT THROUGH TOMORROW MORNING. AN APPROACHING TROUGH
COMBINING WITH A LATE-SEASON PUSH OF MONSOONAL MOISTURE WILL CAUSE
SOME ISOLATED DRY THUNDERSTORMS LATE TOMORROW IN ZONES 451...454...
AND 457...BUT THEY SHOULD BE VERY FEW AND FAR BETWEEN. AS SOUTHERLY
WINDS PICK UP BETWEEN THE RIDGE TO OUR EAST AND THE LOW TO OUR
WEST...GUSTS MAY BRIEFLY REACH" onClick="return popup(this, 'notes')">REACH 30 MPH ACROSS ZONE 457. RH WILL NOT
RECOVER MUCH TONIGHT AND WILL BE VERY LOW DURING THE DAY TOMORROW
IN ALL ZONES.

THE TROUGH MOVES ACROSS THE REGION ON WEDNESDAY AND COUPLED WITH THE
MONSOONAL MOISTURE PUSH...WIDESPREAD ISOLATED SHOWERS AND
THUNDERSTORMS ARE EXPECTED. MANY STORMS WILL LEAN TOWARDS BEING WET
THANKS TO THE ADDITIONAL MOISTURE AND STRONGER DYNAMICS WITH THE
TROUGH...BUT THE WESTERN PORTIONS OF ZONES 451 AND 457 MAY SEE MORE
DRY STORMS AS MOISTURE WILL ALREADY BE EXITING THESE ZONES AS WINDS
ALOFT TURN MORE WESTERLY BY AFTERNOON. WINDS WILL NOT BE AS STRONG
ON WEDNESDAY AFTERNOON AS THEY ARE EXPECTED TO BE TOMORROW
AFTERNOON...AND RH`S WILL GENERALLY BE HIGHER BOTH TOMORROW NIGHT
AND WEDNESDAY...AT LEAST COMPARED TO THE RH`S EXPECTED TONIGHT AND
TOMORROW. RCM &&

.LKN WATCHES/WARNINGS/ADVISORIES...NONE.

$$