AREA FORECAST DISCUSSION

 
 FXUS65 KREV 232342
 AFDREV
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE RENO NV
 342 PM PST MON NOV 23 2009
 
 .SHORT TERM...
 HIGH PRESSURE SURFACE AND ALOFT WILL BUILD OVER THE GREAT BASIN
 THROUGH WEDNESDAY. THE SURFACE HIGH MOVES INTO SOUTHERN IDAHO
 TONIGHT AND BRINGS A NORTHEAST PRESSURE GRADIENT THAT IS REFLECTED
 THROUGH 700MB. THIS WILL REINFORCE INVERSIONS THAT DEVELOP BOTH
 TONIGHT AND WEDNESDAY NIGHT WHICH IN TURN WILL KEEP VALLEY
 TEMPERATURES FROM WARMING VERY QUICKLY. THE EAST FLOW IS ALSO
 EXPECTED TO SUPPRESS DEVELOPMENT OF FREEZING FOG NEAR TRUCKEE
 TONIGHT SO HAVE REMOVED THAT FROM THE GRIDS.
 
 A LOW PRESSURE SYSTEM MOVES INTO THE GULF OF ALASKA ON TUESDAY
 HELPING TO AMPLIFY THE WESTERN CONUS RIDGE. ON WEDNESDAY...SHORT
 WAVE ENERGY EJECT FROM THE GULF OF ALASKA LOW AND BEGINS TO
 FLATTEN THE WESTERN CONUS RIDGE. THE SHORT WAVE MOVES TO THE
 NORTHERN CA COAST THURSDAY AFTERNOON AND ACROSS N CAL THURSDAY
 NIGHT. THE ECMWF MODEL WHICH HAD BEEN WEAKER AND FARTHER NORTH
 WITH THIS FEATURE IS NOW IN BETTER AGREEMENT WITH THE GFS AND HAVE
 THEREFORE ADDED A SLIGHT CHANCE OF RAIN/SNOW SHOWERS FROM THE
 TAHOE BASIN NORTH TO GERLACH...INCLUDING AREAS JUST WEST AND NORTH
 OF RENO. AHEAD OF THIS SYSTEM LOCAL GUSTY WINDS WILL DEVELOP OVER
 WESTERN PORTIONS OF THE CWA ON THANKSGIVING DAY.
 
 VALLEY TEMPERATURES WILL PEAK ON THANKSGIVING DAY IN THE MID TO
 UPPER 50S...VERY CLOSE TO TEMPERATURES IN THE TAHOE BASIN AND MANY
 OTHER SIERRA LOCATIONS. RC
 
 .LONG TERM...FRIDAY THROUGH SUNDAY...
 
 SHORTWAVE TROUGH IS EXPECTED TO MOVE THROUGH SOME TIME BETWEEN 
 THURSDAY NIGHT AND FRIDAY...SO LEFT SOME POPS IN THE NORTHERN HALF 
 OF THE FORECAST AREA FOR FRIDAY. MODELS HAVE BEEN HINTING AT SOME 
 ENERGY COMING DOWN THE BACKSIDE OF THE TROUGH ON FRIDAY 
 NIGHT-SATURDAY TIME FRAME. EVEN THE GFS ENSEMBLES HAVE BEEN SHOWING 
 THIS FEATURE...BUT SEEM TO DIFFER ON TIMING AND STRENGTH. IF THIS 
 BACKSIDE SLIDER MOVED INTO EASTERN NV...AS THE GFS AND ECMWF ARE 
 SUGGESTING...WE COULD SEE SOME PRECIP IN THE EASTERN PORTIONS OF THE 
 FORECAST AREA...INCLUDING PERSHING AND CHURCHILL COUNTIES.
 
 AFTER THESE COLD FRONTS MOVE THROUGH...THIS WILL LEAVE HIGH PRESSURE 
 OVER THE GREAT BASIN TO DOMINATE THROUGH NEXT WEEKEND...WITH COOL  
 EASTERLY FLOW ACROSS THE REGION. BELOW NORMAL TEMPERATURES AND DRY 
 CONDITIONS WILL PREVAIL...AS THE UPPER LEVEL RIDGE SETTLES BACK OVER 
 THE WEST COAST.  HOON
 
 &&
 
 .AVIATION...
 
 HIGH PRESSURE REMAINS OVER THE WEST THROUGH THANKSGIVING...WITH 
 LIGHT WINDS AND DRY CONDITIONS. SLIGHT CHANCE FOR EARLY MORNING 
 IFR/LIFR CONDITIONS...DUE TO FREEZING FOG THE NEXT FEW DAYS. THINK 
 THAT LIGHT EAST FLOW WILL NOT ALLOW FOR WIDESPREAD FOG THOUGH.
 
 NO SIGNIFICANT IMPACTS FOR TRAVEL TO START OF THANKSGIVING WEEKEND. 
 SYSTEM FORECAST TO MOVE INTO THE WEST COAST THURSDAY NIGHT INTO 
 FRIDAY...SHOULD BRING AN INCREASE IN WINDS A CHANCE FOR RAIN/SNOW 
 SHOWERS NORTH OF KTVL-KRNO-KNFL. BRONG/HOON
 
 &&
 
 .REV WATCHES/WARNINGS/ADVISORIES...
 NV...NONE.
 CA...NONE.
 &&
 
 $$
 
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