AREA FORECAST DISCUSSION

FXUS65 KVEF 081802
 AFDVEF
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE LAS VEGAS NV
 1000 AM PST MON NOV 8 2004
 
 .SYNOPSIS...AN AREA OF LOW PRESSURE WILL MOVE OVER SOUTHERN NEVADA 
 TODAY BRINGING SCATTERED SHOWERS TO THE REGION. THE LOW WILL SLOWLY 
 SHIFT EAST INTO UTAH TUESDAY WITH DRIER CONDITIONS EXPECTED BEHIND 
 THE SYSTEM. DRY CONDITIONS ARE EXPECTED TO REMAIN OVER THE AREA 
 THROUGH WEDNESDAY WITH TEMPERATURES GRADUALLY WARMING.
 &&
 
 .UPDATE...THE LOW CENTER COULD BE SEEN MOVING INTO SOUTHERN NEVADA 
 ON SATELLITE IMAGERY THIS MORNING WITH CONVECTION FIRING NEAR THE
 EASTERN SAN BERNARDINO COUNTY BORDER. A MID LEVEL DRY SLOT EXTENDING 
 UP ACROSS THE SOUTHERN HALF OF THE REGION SHOULD ALLOW SUN TO AID 
 CONVECTIVE DEVELOPMENT UNDER THE COLD POOL. SOME SHOWERS MAY PRODUCE 
 LOCALIZED HEAVY SNOW IN THE MOUNTAINS OF SOUTHERN NEVADA BUT THE 
 WARNING WAS DOWNGRADED TO AN ADVISORY. DID RECEIVE A REPORT OF 8 
 INCHES OF NEW SNOW AT THE 9500 FOOT LEVEL IN LEE CANYON...BUT MOSTLY 
 RAIN OVERNIGHT BELOW 9000 FEET. UPDATED FORECAST TO BRING IN LINE 
 WITH LATEST TRENDS. THE 12Z ETA AND GFS INDICATE THE AREA TO WATCH 
 THIS EVENING WILL BE NORTHERN INYO/ESMERALDA AND CENTRAL NYE 
 COUNTIES WITH STRONG UPWARD FORCING.
 &&
 
 .PREV DISCUSSION...
 330 AM PST MON NOV 8 2004
 
 .SHORT TERM...MAIN BAND OF PRECIPITATION HAS SHIFTED NORTH THIS 
 MORNING WITH A FEW THUNDERSTORMS EMBEDDED WITHIN. SCATTERED SHOWERS 
 AND THUNDERSTORMS CONTINUE TO DEVELOP OVER SAN BERNARDINO COUNTY IN 
 CLOSE PROXIMITY TO THE LOW. SNOW LEVELS HAVE BEEN COMING DOWN 
 SLIGHTLY WITHIN THE PAST COUPLE OF HOURS...BUT TEMPERATURES STILL 
 REMAIN FAIRLY WARM. KYLE CANYON RAWS AT 7200 FEET HAS REMAINED 38 
 DEGREES FOR SEVERAL HOURS ALONG WITH SEVERAL OTHER RAWS SITES NEAR 
 THAT ELEVATION. UPSLOPE PRECIPITATION CONTINUES OVER THE SIERRA WITH 
 9 INCHES OF SNOW REPORTED AT ASPENDELL AT 10 PM LAST NIGHT. EXPECTED 
 THE SNOW TO TAPER OFF THIS MORNING AS THE LOW BEGINS TO SHIFT 
 NORTHEAST. WILL ALLOW THE HEAVY SNOW WARNING TO EXPIRE AT 6 AM FOR 
 THAT ZONE. THE MODELS ARE IN GOOD AGREEMENT WITH THE TIMING AND 
 TRACK OF THE LOW AS IT MOVES THROUGH THE CWA TODAY AND TONIGHT. 
 STILL PLENTY OF DYNAMICS ASSOCIATED WITH THE LOW AND AS THE H5 COLD 
 POOL MOVES THROUGH THE SOUTHERN CWA THIS AFTERNOON EXPECT SHOWERS 
 TO BECOME MORE WIDESPREAD. THE MODELS ARE SHOWING LI`S TO BE BETWEEN 
 0/-2 BETWEEN 18Z/00Z THIS AFTERNOON...SO DO EXPECT ISOLATED 
 THUNDERSTORMS TO DEVELOP. THIS WILL ALSO LOWER SNOW LEVELS TO NEAR 
 6500 FEET. THE SHOWERS ARE EXPECTED TO DECREASE FROM WEST TO EAST 
 TONIGHT AS THE LOW TRACKS INTO UTAH. WILL KEEP A FEW SHOWERS INTO 
 TUESDAY OVER THE EASTERN ZONES AS WRAP AROUND MOISTURE WILL STILL BE 
 IN PLACE. RIDGING IS EXPECTED TUESDAY AFTERNOON AND WEDNESDAY FOR 
 MOST ZONES AND EXPECT TEMPERATURES TO WARM A FEW DEGREES. ANOTHER 
 LOW IS FORECAST TO DROP DOWN THE CA COAST THURSDAY WHICH COULD BRING 
 SOME OROGRAPHIC PRECIPITATION TO THE SIERRA. CURRENTLY THE FORECAST 
 HAS 20 POPS FOR THIS AREA AND WILL LEAVE THOSE ALONE.
 
 .LONG TERM...NEXT SYSTEM IS BEING ACCELERATED AT BIT BY THE MODELS 
 AND IS TAKING A MORE INLAND TRACK IN LATEST MODEL RUNS. ECMWF AND 
 GFS LOOK SIMILAR IN BRINGING THE CUTTING OFF LOW THURSDAY DOWN ALONG 
 OR A TAD INLAND OF THE CALIFORNIA COAST WHILE DGEX IS SIMILAR BUT 
 DIFFERS ON FRIDAY ONWARDS. AS A RESULT EXPECT SOME SNOW FALL TO BE 
 POSSIBLE OVER THE SIERRA ZONES THURSDAY. MAIN EVENT WILL BE FRIDAY 
 AND SATURDAY AS LOW SINKS SOUTH AND THEN MOVES INLAND OVER THE AREA. 
 MODELS PRETTY SURE THIS WILL BE A WET EVENT. DGEX DIFFERS IN HAVING 
 THE LOW TRACK FURTHER SOUTH AND WILL GREATLY LESSEN THE QPF/POPS 
 OVER THE NORTHERN PARTS OF THE FORECAST AREA. FOR NOW WENT WITH 
 GFS/ECMWF SOLUTION. WHICH WILL MAKE FOR A WIDESPREAD PRECIPITATION 
 EVENT OVER MOST OF THE AREA SUCH AS IS HAPPENING TODAY.
 
 AVIATION...LOCAL AREAS OF FOG WILL DEVELOP THIS MORNING WITH 
 CEILINGS DROPPING BELOW 500 FEET AND VSBYS LOWERING TO BELOW 1SM. 
 THESE CONDITIONS ARE EXPECTED TO REMAIN THROUGH 14Z BEFORE SOME 
 IMPROVEMENT IS EXPECTED. UPPER LOW PUSHING INTO SOUTHERN NEVADA THIS 
 MORNING WITH ISOLATED LIGHT RAIN SHOWERS EXPECTED THROUGH THE 
 MORNING. SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP THIS 
 AFTERNOON AS THE LOW MOVES OVER THE AREA AND DESTABILIZES THE 
 ATMOSPHERE WITH ITS COLD AIR ALOFT. CONDITIONS ARE EXPECTED TO 
 IMPROVE THIS EVENING.
 &&
 
 .VEF WATCHES/WARNINGS/ADVISORIES...
 .NV...HEAVY SNOW WARNING UNTIL 4 PM THIS AFTERNOON FOR NV ZONES 18 
       AND 19.
 .AZ...NONE.
 .CA...HEAVY SNOW WARNING UNTIL NOON TODAY CA ZONE 26.
 &&
 
 

 
 ADAIR/GORELOW/MORGAN
 
 
 
 
 

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