FXUS65 KVEF 241741 AAA
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
941 AM PST THU DEC 24 2009

.SYNOPSIS...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH CHRISTMAS 
DAY...WITH QUIET WEATHER EXCEPT FOR GUSTY NORTH WINDS DOWN THE 
COLORADO RIVER VALLEY. CLOUDS WILL INCREASE SATURDAY AS LOW PRESSURE 
APPROACHES...AND MOST AREAS WILL SEE A SLIGHT CHANCE OF 
PRECIPITATION SUNDAY AND MONDAY.
&&

.UPDATE...NORTH WIND GUSTS HAVE DEVELOPED ALONG THE LOWER COLORADO 
RIVER WHICH ARE COVERED WELL IN THE GOING FORECAST. OTHERWISE...THE 
GREAT BASIN AND MOJAVE DESERT LIE UNDER A DRY NORTH FLOW AND SOME 
VERY FINE CIRRUS WILL BE SEEN. WILL REFRESH THE ZONES AND GET RID OF 
ANY MENTION OF MORNING.
&&

.AVIATION...FOR MCCARRAN...WINDS EXPECTED TO REMAIN UNDER 7 KTS FROM 
THE NORTHEAST THROUGH 02Z TODAY THEN BECOMING LIGHT AND VARIABLE. 
NO SIGNIFICANT WEATHER IS EXPECTED THROUGH SATURDAY WITH THE NEXT 
AREA OF LOW PRESSURE BRINGING MINIMAL IMPACTS TO THE REGION SUNDAY 
AND MONDAY. 

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 
TODAY AND PERSISTING THROUGH THE AFTERNOON. WIND GUSTS OF 25 TO 35 
MPH ARE POSSIBLE AT KEED AND KIFP. OTHERWISE...NO SIGNIFICANT 
WEATHER IS EXPECTED THROUGH SATURDAY WITH MOSTLY CLEAR SKIES AND DRY 
CONDITIONS. 
&&

.PREV DISCUSSION...215 AM PST THU DEC 24...SATELLITE SHOWS 
MOSTLY CLEAR SKIES AREAWIDE WITH CIRRUS APPROACHING FROM THE WEST. 
SURFACE OBS SHOW SEASONABLY CHILLY TEMPERATURES AND LIGHT WINDS 
EXCEPT FOR ISOLATED GUSTY NORTH WINDS AT A FEW SPOTS WHERE TERRAIN 
FUNNELING WAS OCCURRING. ONE MORE DAY OF LOCALLY STRONG NORTH WINDS 
CAN BE EXPECTED DOWN THE COLORADO RIVER TODAY...WITH CHRISTMAS DAY 
SEEING WINDS STILL GUSTY BUT NOT AS STRONG. THE HIGH AMPLITUDE SHORT 
WAVELENGTH RIDGE NEAR THE WEST COAST WILL REMAIN OUR DOMINANT 
FEATURE THROUGH CHRISTMAS DAY WHILE A HUGE STORM DEEPENS IN THE MID 
MISSISSIPPI RIVER VALLEY. BY SATURDAY...A SHORTWAVE TROUGH ROTATES 
AROUND THE SOUTHERN SIDE OF THE GULF OF ALASKA LOW AND COMES INTO 
THE WEST COAST...BREAKING DOWN THE RIDGE AND TURNING OUR MID LEVEL 
FLOW MORE ZONAL AS THE SHORT TERM ENDS SATURDAY NIGHT. THIS WILL 
BRING IN A LOT OF HIGH CLOUDS AREAWIDE SATURDAY AND SATURDAY 
NIGHT...WITH SLIGHT CHANCE POPS IN THE INYO COUNTY MOUNTAINS 
SATURDAY NIGHT.

.LONG TERM...THE EXTENDED FEATURES A PROGRESSIVE PATTERN WITH 
EMBEDDED SHORTWAVES FOLLOWED BY WEAK RIDGES. PROSPECTS FOR 
MEASURABLE PRECIPITATION ARE LIMITED WITH A PACIFIC SYSTEM SET FOR 
THE LATTER HALF OF THE WEEKEND. MODELS ESSENTIALLY TAKE SHORTWAVE 
ENERGY DOWN ALONG THE WEST COAST AND THEN SOUTH OF THE AREA. MODEL 
QPF IS LIGHT AT BEST AND NOT EVERYWHERE WILL SEE SHOWER ACTIVITY 
BASED ON THE LATEST RUNS. THERE IS ANOTHER SHOT MID TO LATE IN THE 
WEEK BUT THAT IS UNIMPRESSIVE AS WELL. TEMPERATURE FORECASTS WERE 
NOT CHANGED MUCH BASED ON THE OVERALL TROUGH PATTERN KEEPING VARYING 
AMOUNTS OF CLOUD COVER AROUND AND GENERALLY COOL NW FLOW.
&&

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

$$

PIERCE/GORELOW/MORGAN/SALMEN

HTTP://WEATHER.GOV/LASVEGAS