000
FXUS65 KVEF 102304
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
300 PM PST WED MAR 10 2010
.SYNOPSIS...A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE AREA
THURSDAY AND FRIDAY FOR A DRYING TREND AND WARMER DAYTIME
TEMPERATURES. ANOTHER SYSTEM THEN DROPS INTO THE GREAT BASIN ON
SATURDAY RETURNING TO A CHANCE OF SHOWERS ACROSS MAINLY THE MOUNTAIN
AREAS OF SOUTHERN NEVADA AND NORTHWEST ARIZONA.
$$
.SHORT TERM...TONIGHT THROUGH FRIDAY...UPPER TROUGH QUICKLY
TRANSITIONING ACROSS THE CWA THIS AFTERNOON WITH FORECAST POSITION
OVER EASTERN ARIZONA BY 06Z THURSDAY. SCATTERED SHOWERS HAVE FORMED
ACROSS EXTREME SOUTHERN NEVADA AND NORTHWEST ARIZONA AND EXPECT
THESE SHOWERS TO DECREASE BY EARLY EVENING AS THE TROUGH SHIFTS
EAST. NORTHERLY FLOW BEHIND THE SYSTEM ACROSS NEVADA AND WEST FLOW
ACROSS THE SAN BERNARDINO COUNTY DESERTS HAVE DECREASED AND WILL
CANCEL THE WIND ADVISORIES FOR THESE AREAS. RIDGE TO BEGIN TO BUILD
OVER THE AREA TONIGHT AND INTO THURSDAY AND THEN REMAIN THE DOMINANT
FEATURE INTO FRIDAY. THIS WILL RESULT IN DRIER CONDITIONS ACROSS THE
CWA WITH AFTERNOON TEMPERATURES WARMING TO NEAR NORMAL BY FRIDAY.
WILL SEE SOME NORTH SURFACE WINDS ON THURSDAY AS THE RIDGE BUILDS
OVER THE AREA...BUT GUSTINESS WILL BE CONFINED TO THE NORTH WIND
PRONE AREAS SUCH AS THE COLORADO RIVER VALLEY.
.LONG TERM...FRIDAY EVENING THROUGH WEDNESDAY...GFS SLOWED ITS TREND
TOWARDS THE NAM12 AND ECMWF SOLUTION THIS WEEKEND. THE ECMWF AND
NAM12 TAKE THE NEXT SYSTEM INTO SOUTHEAST NEVADA SATURDAY BEFORE
GOING INTO ARIZONA SATURDAY EVENING...WHICH IS WHEN THE GFS COMES IN
SYNC WITH IT. MOST OF THE 12S GFS ENSEMBLE MEMBERS GO THE WAY OF
ITS OPERATIONAL AND ENSEMBLE MEAN IN HAVING THE SYSTEM DROP INTO
UTAH. WENT WITH THE ECMWF AND NAM SOLUTIONS. THIS WILL BRING MORE
PRECIPITATION CHANCES TO OUR NORTHERN AND NORTHEAST ZONES SATURDAY.
PRETTY MUCH LEFT THE PREVIOUS POP FORECAST AS IS EXPECT FOR
INCREASING POPS IN NORTHERN MOHAVE SATURDAY AS THE LOW PASSES OVER
IT.
PRIMARY PROBLEMS WILL BE WINDS AND TEMPERATURES. THE SATURDAY SYSTEM
LOOKS SIMILAR TO TODAYS ONGOING EVENT. EXPECT BREEZY CONDITIONS IN
SOUTHERN SAN BERNARDINO AND POSSIBLY INYO COUNTIES AHEAD OF THE
SYSTEM AND BREEZY IN NEVADA POST FRONTAL SATURDAY. NEXT WIND
CONDITION TO LOOK AT WOULD BE THE COLORADO RIVER VALLEY/LAKES ZONES
SUNDAY. HIGH PRESSURE WILL BUILD IN SUNDAY AND THE PRESSURE GRADIENT
TIGHTENS IN SOUTHERN NEVADA TO MAKE FOR FUNNELING THERE.
AS THE SATURDAY SYSTEM MOVES OUT RIDGING FORECAST TO MOVE IN ALONG
WITH COOLER AND DRIER AIR FOR THE WEEKEND BEFORE SUBSIDENCE STARTS
FOR MUCH OF THE REST OF THE EXTENDED. A DECENT WARM UP EXPECTED
THROUGH MID WEEK AND LAS VEGAS WILL COME CLOSE TO AND MAYBE EXCEED
THE 80 DEGREE MARK AND DEATH VALLEY THE 90 DEGREE MARK.
&&
.AVIATION...FOR MCCARRAN...WINDS SHOULD GRADUALLY SUBSIDE THE REST
OF THIS AFTERNOON AND THE GUSTINESS WILL BE OVER AROUND 03-04Z. THE
CLOUD COVER WILL MOVE OUT TONIGHT ALONG WITH CHANCES OF A RAIN
SHOWER OVER KLAS...THOUGH SNOW SHOWERS ARE POSSIBLE OVER THE SPRING
MOUNTAIN THIS EVENING ALONG WITH A BRIEF RAIN SHOWER OVER KLAS TIL
ABOUT 04Z. CEILINGS SHOULD STAY ABOVE 3000 FEET UNDER THE SHOWERS.
NORTHWEST TO NORTH WINDS WILL PERSIST THROUGH THE NIGHT AND INTO
THURSDAY UNDER FEW TO SCT CLOUDS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...A FRONT AND LOW PRESSURE SYSTEM MOVING THROUGH
SOUTHWEST UTAH AND SOUTHEAST NEVADA WILL BRING A CHANCE FOR
RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS IN SOUTHERN NEVADA AND
NORTHWEST ARIZONA THROUGH THIS EVENING. GUSTY WEST TO NORTHWEST
WINDS TO ABOUT 30 KNOTS ARE POSSIBLE THROUGH MID EVENING. FOR
THURSDAY THE AREA WILL HAVE FEW TO SCT CLOUDS WITH NORTH WINDS OVER
THE AREA WITH GUSTS TO 20 KNOTS IN THE COLORADO RIVER VALLEY.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
JENSEN/JACQUES
HTTP://WEATHER.GOV/LASVEGAS
