FXUS65 KVEF 240511 CCA
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
910 PM PST WED DEC 23 2009

.SYNOPSIS...HIGH PRESSURE WILL SLOWLY BUILD OVER THE AREA THROUGH 
THE REMAINDER OF THE WEEK WITH CLEAR SKIES AND NEAR NORMAL 
TEMPERATURES. MOST OF THE AREA WILL SEE LIGHT WINDS STARTING 
THURSDAY WITH THE EXCEPTION OF THE COLORADO RIVER VALLEY WHERE 
LOCALLY BREEZY CONDITIONS WILL PERSIST. 
&&

.UPDATE...THERE HAVE BEEN SOME LOCALIZED WIND GUSTS THIS EVENING IN 
THE LAS VEGAS VALLEY TO AROUND 30 MPH. THE NORTH TO SOUTH PRESSURE 
GRADIENTS HAVE BEEN FAIRLY STEADY AND WE HAVE STAYED MIXED...SO I
UPDATED THE TABULAR PRODUCTS TO REFLECT SOME HIGHER WINDS FOR THE 
NEXT FEW HOURS. OTHERWISE...NO CHANGES. EXPECT BREEZY CONDITIONS TO 
DEVELOP DURING THE MORNING HOURS DOWN THE COLORADO RIVER 
VALLEY...ESPECIALLY ALONG THE NORTH...SOUTH ORIENTED LOCATIONS.

.PREV DISCUSSION...WINDS HAVE BEEN SLOW TO DIMINISH THIS 
AFTERNOON AS SURFACE PRESSURE GRADIENTS HAVE YET TO FULLY RELAX. 
MOST LOCATIONS WILL SEE A DECREASE IN WIND SPEEDS BY SUNSET WITH THE 
EXCEPTION OF THE COLORADO RIVER VALLEY WHERE GUSTY NORTH WINDS MAY 
PERSIST THROUGH THIS EVENING. HIGH PRESSURE WILL CONTINUE TO BUILD 
OVER THE AREA THROUGH THE REMAINDER OF THE WEEK WITH CLEAR SKIES AND 
NEAR NORMAL TEMPERATURES. GUSTY WINDS AT TIMES WILL STILL AFFECT THE 
COLORADO RIVER VALLEY THROUGH CHRISTMAS DAY BEFORE WEAKENING AND 
BRINGING LIGHTER WINDS BY SATURDAY. MODELS ARE SHOWING THE NEXT 
PACIFIC SYSTEM APPROACHING THE COAST SATURDAY AFTERNOON WITH 
PRECIPITATION SPREADING INTO THE SIERRA SATURDAY NIGHT. THE ECMWF IS 
DEEPER AND STRONGER THAN THE CURRENT GFS...BUT THE MAIN AFFECTS FROM 
THIS SYSTEM WILL NOT BE FELT UNTIL EARLY NEXT WEEK. DID GO AHEAD AND 
INCREASE POPS SLIGHTLY FOR THE INYO COUNTY AND ESMERALDA COUNTY 
MOUNTAINS SATURDAY NIGHT WITH DRY CONDITIONS ELSEWHERE. 

.LONG TERM...FOR THE PERIOD BEGINNING SUNDAY MORNING...WHILE MODEL 
DIFFERENCES CONTINUE IN THE DETAILS...OVERALL CONSENSUS POINTS 
TOWARDS AN AREA OF LOW PRESSURE IMPACTING THE REGION SUNDAY THROUGH 
MONDAY...WITH ANY CHANGES MADE THIS AFTERNOON WEIGHING HEAVILY ON 
THE EC...GEM...AND GEFS...WHICH OFFER THE BEST AGREEMENT. THERE DOES 
NOT APPEAR TO BE SIGNIFICANT MOISTURE TAP IN ANY SCENARIO ... 
HOWEVER...THERE SHOULD BE SUFFICIENT DYNAMICS FOR PRECIP ACROSS THE 
MAJORITY OF THE CWA...ALBEIT LIGHT. THEREFORE HAVE KEPT POPS ABOUT 
10 TO 20 ABOVE CLIMO NORMS...WHICH RESULTS IN PRECIP IN THE FORECAST 
FOR MOST LOCATIONS. FURTHER REFINEMENT WILL BE NECESSARY AS SOON AS 
DETAILS BEGIN TO SURFACE IN MODEL PROGS. AFTER A BRIEF 
BREAK...ANOTHER SYSTEM WILL MOVE INTO THE REGION WEDNESDAY/THURSDAY 
...RESULTING IN ANOTHER PERIOD OF UNSETTLED WEATHER. LITTLE CHANGE 
WAS NEEDED TO TEMPERATURES...WITH BELOW AVERAGE TEMPERATURES 
EXPECTED THROUGHOUT THE TERM AS WE REMAIN IN THIS TROFY PATTERN. 
&&

.AVIATION...FOR MCCARRAN...NORTHERLY WINDS WILL CONTINUE OVERNIGHT 
WITH OCCASIONAL GUSTS TO 25 KTS. THE GUSTS SHOULD DIMINISH BY 
12Z. THE NEXT AREA OF LOW PRESSURE IS NOT EXPECTED TO IMPACT THE 
REGION UNTIL LATE THIS UPCOMING WEEKEND. 

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...THE MAIN ISSUE WILL BE NORTHERLY WINDS THAT WILL 
DEVELOP ALONG THE COLORADO RIVER VALLEY DURING THE MORNING HOURS ON 
THURSDAY AND PERSISTING THROUGH THE AFTERNOON. WIND GUSTS OF 25 TO 
35 MPH ARE POSSIBLE AT KEED AND KIFP. OTHERWISE...MOSTLY CLEAR SKY 
CONDITIONS CAN BE EXPECTED. 
&&   

.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&

$$

CZYZYK/GORELOW/KENNEDY

HTTP://WEATHER.GOV/LASVEGAS