AREA FORECAST DISCUSSION

 
 FXUS65 KVEF 052202
 AFDVEF
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE LAS VEGAS NV
 300 PM PST FRI SEP 5 2008
 
 .SYNOPSIS...HIGH PRESSURE AND A VERY DRY AIR MASS WILL KEEP THE 
 ENTIRE FORECAST AREA SUNNY AND WARM THROUGH THE WEEKEND. MOISTURE 
 WILL GRADUALLY INCREASE FROM THE SOUTH EARLY NEXT WEEK SUPPORTING A 
 SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS OVER NORTHWEST 
 ARIZONA ON TUESDAY.  
 &&
 
 .SHORT TERM...A RIDGE OF HIGH PRESSURE RUNNING ALONG 140W WILL KEEP 
 THE FORECAST AREA IN A DRY NORTHWEST FLOW REGIME THROUGH THE 
 WEEKEND...WITH LITTLE DAY TO DAY CHANGE IN TEMPERATURES AS HEIGHT 
 CHANGE REMAINS MINIMAL ALOFT. MODELS HAVE BEEN SOMEWHAT CONSISTENT 
 IN SHOWING A SHORTWAVE EMBEDDED IN THE FLOW CUTTING OFF JUST OFF THE 
 SOUTHERN CALIFORNIA EARLY NEXT WEEK. MAIN IMPACT THIS WILL HAVE ON 
 THE FORECAST AREA WILL LIKELY BE AN INCREASE IN CLOUD 
 COVERAGE...WITH MODELS INDICATING ANY INCREASE IN MOISTURE WILL BE 
 CONFINED TO A RELATIVELY THIN LAYER. HAVE ADDED SLIGHT CHANCES FOR 
 PRECIP ON TUESDAY HOWEVER...WITH A LITTLE MORE INSTABILITY INDICATED 
 OVER THE AREA DURING THE FIRST HALF OF THE WEEK. WINDS THROUGHOUT 
 THE PERIOD WILL BE GENERALLY LIGHT.
 
 .LONG TERM...MEDIUM RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT ON 
 MAINTAINING A BAGGY POSITIVE TILT TROUGH ACROSS NEVADA AND SOUTHERN 
 CALIFORNIA THROUGH AT LEAST THURSDAY. BIGGEST DIFFERENCES COME THE 
 FOLLOWING WEEKEND IN THE DAY 6-8 TIME FRAME. GFS AND DGEX DEPICT AN 
 UPPER RIDGE BUILDING INTO THE GREAT BASIN FROM MEXICO WITH A REMNANT 
 LOW OFFSHORE...LEAVING OUR FORECAST AREA UNDER A SOUTHWEST FLOW WITH 
 PRECIPITATION UNLIKELY BUT A GOOD CHANCE OF SOME INTERMITTENT MIDDLE 
 AND HIGH CLOUDS. THE ECMWF SUGGESTS THE CLOSED LOW WILL LIFT OUT 
 ACROSS SOUTHERN NEVADA NEXT SATURDAY AND SUNDAY WITH THE MEXICO 
 RIDGE LEANING TOWARD THE NORTHEAST INTO THE CENTRAL PLAINS. THIS 
 SCENARIO WOULD INTRODUCE A HIGHER CHANCE OF THUNDERSTORMS AND 
 MEASURABLE PRECIPITATION ACROSS THE SOUTHERN HALF OF THE REGION NEXT 
 WEEKEND. ASIDE FROM THE FACT THAT IT IS STILL A LONG WAY OFF...THERE 
 IS A STRONG POSSIBILITY THAT HURRICANE IKE WILL MOVE BE APPROACHING 
 THE GULF COAST STATES BY THAT TIME AS WELL...INTRODUCING YET ANOTHER 
 COMPLICATION TO THE OVERALL UPPER AIR PATTERN AS IT INTERACTS WITH 
 THE DOWNSTREAM STEERING FLOW. THEREFORE...FOR NOW DECIDED TO JUST 
 PLAY A LARGELY CLIMO FORECAST FOR THE LONG TERM. 
 &&
 
 .AVIATION...FOR MCCARRAN...NO SIGNIFICANT WEATHER IMPACTS TO AIR 
 TRAFFIC FLOW EXPECTED FOR THE NEXT TWO DAYS. SKIES WILL BE CLEAR 
 WITH LIGHT EAST WINDS DEVELOPING IN THE LATE MORNING...FOLLOWED BY 
 SOUTHWEST AFTERNOON WINDS AVERAGING AROUND 10 KNOTS.   
 
 FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
 CALIFORNIA...NO SIGNIFICANT WEATHER IMPACTS TO AIR TRAFFIC FLOW 
 EXPECTED FOR THE NEXT TWO DAYS. SKIES WILL REMAIN CLEAR AND WINDS 
 WILL GENERALLY BE FROM THE SOUTH TO SOUTHWEST AT AROUND 10 KNOTS 
 WITH A FEW GUSTS NEAR 20 KNOTS DURING THE LATE AFTERNOON.
 &&
 
 .VEF WATCHES/WARNINGS/ADVISORIES...
 NV...NONE.
 AZ...NONE.
 CA...NONE.
 &&
 
 

 
 KENNEDY/RUNK
 
 HTTP://WEATHER.GOV/LASVEGAS
 
 
 
 
 
 
 

Webmaster
US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Tucson Weather Forecast Office
520 North Park Ave, Suite 304
Tucson, AZ 85719

Tel: (520) 670-6526