FXUS65 KVEF 252313
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
310 PM PST FRI DEC 25 2009

.SYNOPSIS...HIGH PRESSURE OVER THE SOUTHWEST STATES WILL GIVE WAY 
LATE SATURDAY TO A SERIES OF WEAK STORMS AFFECTING THE REGION SUNDAY 
THROUGH NEW YEARS DAY. THIS PATTERN WILL MAINLY BRING PERIODS OF 
CONSIDERABLE CLOUDINESS TO THE REGION AND POSSIBLY A FEW FLURRIES TO
THE HIGHER PEAKS.
&&

.SHORT TERM...A HIGHLY AMPLIFIED RIDGE SHIELDING THE WEST FROM ANY 
SIGNIFICANT WEATHER WILL BE UNDERCUT LATE SATURDAY BY ENERGY 
EJECTING FROM A BROAD EASTERN PACIFIC TROUGH. A SUBSTANTIAL PLUME OF 
MID AND HIGH LEVEL MOISTURE...CURRENTLY ALONG 130W...WILL BE PULLED 
ACROSS THE FORECAST AREA SATURDAY AFTERNOON THROUGH SUNDAY. NO 
SIGNIFICANT DIFFERENCES EXIST AMONG THE MODELS AND THE FORECAST IS 
BASED ON THE GFS SOLUTION. TIME-HEIGHT SECTIONS INDICATE SUFFICIENT 
MOISTURE FOR SOME LIGHT SNOW TO FALL ON THE HIGHEST PEAKS SATURDAY 
NIGHT AND EARLY SUNDAY BUT THE MAIN RESULT WILL BE FAIRLY DENSE 
CLOUD COVER. ADDITIONAL ENERGY ENTERING THE EASTERN PACIFIC TROUGH 
IS FORECAST TO DIG THE SYSTEM TOWARD BAJA. THIS WILL LEAVE A VERY 
WEAK TROUGH WITH MID LEVEL MOISTURE CROSSING THE REGION MONDAY FOR 
MORE CLOUDS BUT LITTLE PRECIPITATION EXCEPT POSSIBLY AGAIN ON THE 
HIGHEST PEAKS. A PERSISTENT NORTH/SOUTH SURFACE PRESSURE GRADIENT IS 
FORECAST TO HOLD ALONG THE SOUTHERN NEVADA/UTAH BORDER THROUGH 
MONDAY FOR CONTINUED BREEZES DOWN THE COLORADO RIVER VALLEY...THOUGH 
SPEEDS SHOULD BE DOWN A LITTLE FROM TODAY. HIGH TEMPERATURES WILL 
DROP A FEW DEGREES AND LOW TEMPERATURES SHOULD COME UP SLIGHTLY AS A 
RESULT OF THE CLOUDS.

.LONG TERM...SYSTEM ON TUESDAY STILL FORECAST TO TRACK SOUTH OF THE 
AREA WITH SOME POTENTIAL OF WRAP AROUND MOISTURE AFFECTING THE FAR 
SOUTHERN AREAS OF SAN BERNARDINO AND MOHAVE COUNTIES...ALTHOUGH 
CHANCES ARE LOOKING LESS LIKELY WITH EACH MODEL RUN. THE ECMWF AND 
TO A WEAKER EXTENT THE GFS IS SHOWING A SECOND PIECE OF ENERGY 
MOVING SOUTHEAST THROUGH NORTHERN NEVADA TUESDAY AFTERNOON AND 
NIGHT. THIS IS NOT EXPECTED TO BRING MUCH TO OUR CWA AND ONLY HAVE 
GHOST POPS MENTIONED ACROSS THE FAR NORTHERN ZONES. MODELS ARE 
INDICATING RIDGING DEVELOPING WEDNESDAY WHICH IS FORECAST TO REMAIN 
THROUGH THE REMAINDER OF THE WEEK. TEMPERATURES ARE FORECAST TO 
REMAIN AT OR SLIGHTLY BELOW NORMAL THROUGH NEXT WEEK. &&

.AVIATION...FOR MCCARRAN...NO SIGNIFICANT WEATHER THROUGH SUNDAY 
WITH VARIABLE WINDS BECOMING NORTHEAST UNDER 8KTS EACH AFTERNOON AND 
LIGHT SOUTHWEST AT NIGHT. VARIABLE AMOUNTS OF HIGH CLOUDS EXPECTED 
THROUGH SATURDAY AFTERNOON WITH A BAND OF MID/LOW LEVEL CLOUDS 
MOVING ACROSS SOUTHERN NEVADA LATE SATURDAY NIGHT INTO SUNDAY.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...NORTH WINDS AROUND 15-25 KNOTS WILL CONTINUE DOWN THE 
COLORADO RIVER THROUGH 02Z BEFORE DISSIPATING TO UNDER 10 KNOTS. 
NORTH WINDS ARE EXPECTED TO INCREASE ONCE AGAIN DOWN THE COLORADO 
RIVER SATURDAY AFTERNOON TO AROUND 10-20 KNOTS. ELSEWHERE WINDS WILL 
GENERALLY REMAIN UNDER 10 KNOTS THROUGH SATURDAY. THERE WILL BE SOME 
INCREASING CLOUDS SATURDAY AFTERNOON WITH SLIGHT CHANCE OF SNOW OVER 
THE SIERRA WITH DRY CONDITIONS ELSEWHERE. 
&&

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

$$

ADAIR/GORELOW

HTTP://WEATHER.GOV/LASVEGAS