Issued by NWS Las Vegas, NV
000 FXUS65 KVEF 222314 AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 314 PM PST SUN NOV 22 2009 .SYNOPSIS...AN AREA OF HIGH PRESSURE OVER THE EASTERN PACIFIC WILL GRADUALLY SHIFT EAST AND BE OVER THE GREAT BASIN TUESDAY AND WEDNESDAY. SOME HIGH CLOUDS WILL DRIFT OVERHEAD FROM TIME TO TIME WHILE GUSTY NORTH WINDS WILL OCCUR DOWN THE COLORADO RIVER VALLEY MONDAY THROUGH WEDNESDAY. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE WEEK. && .SHORT TERM...SHORTWAVE CLIPPING NORTHEAST NEVADA THIS AFTERNOON WILL CONTINUE EAST INTO THE CENTRAL ROCKIES LEAVING THE SOUTHERN GREAT BASIN AND MOJAVE DESERT UNDER A DRY NORTHWEST FLOW TONIGHT. RIDGE OVER THE EASTERN PACIFIC WILL SLOWLY SHIFT EASTWARD AND BE OVER THE GREAT BASIN TUESDAY AND WEDNESDAY. MODELS CONSISTENT IN BUILDING A SURFACE HIGH OVER THE NORTHERN GREAT BASIN MONDAY INTO WEDNESDAY. STRONGEST NORTH WIND WILL HAPPEN DOWN THE OVERTON ARM...THEN SOUTH FROM HOOVER DAM TO LAKE HAVASU CITY THROUGH MIDWEEK. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL THROUGH WEDNESDAY. .LONG TERM...DIFFERENT DAY SAME CHALLENGES. GUIDANCE FROM MODELS HAS NOT CHANGED MUCH. THE EXTENDED ON THURSDAY STARTS WITH A CONTINUATION OF RIDGING OVER THE AREA AND ABOVE NORMAL TEMPERATURES. FRIDAY WILL SEE THE APPROACH OF THE NEXT TROUGH TO MOVE INTO THE REGION. AS HAS BEEN THE CASE THE LAST FEW DAYS THE GFS CONTINUES TO TO BE FASTEST WITH THE SYSTEM AND KEEPS IT PREDOMINATELY NORTH OF THE AREA. THE ECMWF IS STARTING TO SHOW SOME HITS OF LESSENING ITS CONSISTENT TREND OF BEING DEEPER AND SLOWER WITH IT AND FORMING A CUT OFF LOW OVER THE SOUTHWEST STATES...BUT IT STILL DOES THIS BY SUNDAY MORNING WHILE THE REST OF THE SPLIT SYSTEMS RACES OFF TO THE EAST LIKE THE GFS. IN THE MEANWHILE THE GEM SEEMS TO TAKE A BLEND OF THE TWO IN ITS APPROACH. WENT THIS WAY AS WELL. WILL SHOW A CLOUD COVER INCREASE SATURDAY IN OUR NORTHERN ZONES AND STILL KEEP GHOST POPS UP THERE AS WELL. I DID LOWER TEMPERATURES A BIT AS WELL AS SOME COLD AIR WILL COME IN NO MATTER WHICH SCENARIO PLAYS OUT. && .AVIATION...FOR MCCARRAN...NO SIGNIFICANT WEATHER IS EXPECTED OVER THE NEXT 48 HOURS. WINDS WILL WILL CONTINUE LIGHT FROM THE NORTHEAST THROUGH SOUTHEAST THIS AFTERNOON AND UNTIL ABOUT 04Z WHERE THE USUAL SOUTHWEST WINDS WILL GO FOR THE REST OF THE NIGHT. A WIND SHIFT IS EXPECTED EARLY MONDAY MORNING TO THE NORTHEAST AT ABOUT 16Z AND STAY THERE THE REST OF THE DAY AT ABOUT 8-10KTS. THE HIGH LEVEL CLOUD COVER WILL PERSIST UNTIL ABOUT 18-20Z MONDAY BEFORE GOING SCATTERED. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...LIGHT WINDS FOLLOWING LOCAL DIURNAL PATTERNS SCATTERED TO BROKEN HIGH CLOUDS CAN BE EXPECTED OVER THE NEXT SEVERAL DAYS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && $$ PIERCE/JACQUES HTTP://WEATHER.GOV/LASVEGAS
