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000
FXUS65 KVEF 150409
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
908 PM PDT TUE MAY 14 2013

.SYNOPSIS...ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE
OVER THE SOUTHERN SIERRA THROUGH THIS EVENING AS A WEAK UPPER LEVEL
LOW PRESSURE SYSTEM MOVED OVERHEAD. THIS SYSTEM WILL ALSO MARK THE
BEGINNING OF A COOLING TREND ACROSS THE AREA THAT WILL LAST THROUGH
FRIDAY. BREEZY TO WINDY CONDITIONS WILL BE SEEN EACH AFTERNOON
THROUGH THE END OF THE WEEK. TEMPERATURES WILL BEGIN TO REBOUND THIS
WEEKEND AND INTO EARLY NEXT WEEK.
&&

.UPDATE...SHOWERS/THUNDERSTORMS ASSOCIATED WITH AN UPPER LOW
DEVELOPED ALONG THE EASTERN SIERRA SLOPES THIS AFTERNOON/EVENING AND
CREATED SOME PRETTY STRONG OUTFLOW IN THE OWENS VALLEY. SEVERAL
REPORTS WERE RECEIVED OF DOWNED TREE LIMBS AND EVEN SOME SMALL TREES
BLOWN OVER IN THE BISHOP AREA. THE SHOWERS AND THUNDERSTORMS HAVE
SINCE DIMINISHED AND SKIES WERE GENERALLY MOSTLY CLEAR ACROSS THE
FORECAST AREA. WINDS WERE BEGINNING TO DECREASE OVERALL BUT SOME
LOCALLY BREEZY CONDITIONS WILL PERSIST ALL NIGHT AS THE LOW MOVES
EAST INTO NEVADA. THE FORECAST WAS IN PRETTY GOOD SHAPE BUT I DID
TWEAK SKY COVER GRIDS FOR TONIGHT AND REMOVED ANY MENTION OF
SHOWERS/THUNDERSTORMS SINCE THAT THREAT HAS ENDED.  -HARRISON-
&&

.PREV DISCUSSION...
310 PM PDT TUE MAY 14 2013

.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...LATEST SATELLITE LOOPS
SHOWED A N-S BAND OF HIGH CLOUDS CENTERED OVER LAS VEGAS AT 22Z THIS
AFTERNOON WITH SOME DEVELOPING CUMULUS OVER THE HIGHER TERRAIN OF
THE FORECAST AREA. MOST OF THESE CLOUD WILL NOT AMOUNT TO
ANYTHING. HOWEVER...THE CLOUDS OVER THE SOUTHERN SIERRA AND WHITE
MOUNTAINS STILL RETAIN THE POTENTIAL TO DEVELOP INTO SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING AS A WEAK UPPER LEVEL LOW
MOVES TOWARD THE AREA. THIS SYSTEM HAS ALSO KICKED UP WINDS A BIT
MORE THAN INITIALLY EXPECTED TODAY...BUT WINDS FOR THE MOST PART
HAVE REMAINED UNDER ADVISORY CRITERIA.

THIS SYSTEM WILL USHER IN SLIGHTLY COOLER TEMPERATURES ALOFT AND
WILL MARK THE BEGINNING OF A COOLING TREND THAT WILL LAST THROUGH
FRIDAY. BREEZY TO WINDY CONDITIONS ARE EXPECTED EACH AFTERNOON
THROUGH FRIDAY. MODEL WIND FORECASTS ARE QUITE DIFFERENT BY THURSDAY
AFTERNOON WITH THE NAM-BASED HIGH-RES MODELS BRINGING IN SOME
DECENT DOWNSLOPE WINDS ACROSS THE SIERRA...WHILE THE HIGH-RES GFS IS
MUCH WEAKER. WILL CONTINUE TO MONITOR FOR THE POTENTIAL OF WIND/FIRE
PRODUCTS AREA-WIDE THURSDAY. BY FRIDAY...MOISTURE WILL BEGIN TO
ADVECT INTO THE AREA AS THE NEXT TROUGH MOVES ACROSS THE REGION.
THIS SHOULD LIMIT FIRE WEATHER CONCERNS...BUT WILL BRING A CHANCE OF
SHOWERS/THUNDERSTORMS TO THE NORTHERN PORTIONS OF THE FORECAST AREA
FRIDAY INTO FRIDAY NIGHT.

.LONG TERM...SATURDAY THROUGH TUESDAY...THE MAIN THEME IN THE
EXTENDED WILL BE A WARMING TREND THROUGH THE PERIOD. NORTHWEST
FLOW ALOFT IS EXPECTED TO REMAIN IN PLACE ACROSS THE AREA ON
SATURDAY BETWEEN A DEPARTING MID AND UPPER LEVEL TROUGH AXIS OVER
THE ROCKIES AND A MID AND UPPER LEVEL RIDGE LOCATED JUST OFFSHORE OF
SOCAL. AS WE MOVE INTO MONDAY AND TUESDAY THE RIDGE CENTER OFFSHORE
IS EXPECTED TO SLIDE EAST TOWARD SOCAL AND ARIZONA WHICH WILL RESULT
IN A WARMING TREND AS THE FLOW ALOFT TURNS MORE TO THE WEST AND
SOUTHWEST AND HEIGHTS RISE. STRONG SUBSIDENCE WILL RESULT IN A
RELATIVELY CLEAR SKY. AS WE MOVE INTO TUESDAY AN AREA OF LOW
PRESSURE IS EXPECTED TO DROP SOUTH FROM BRITISH COLUMBIA OR JUST
OFFSHORE OF IT AND HEAD TOWARD WASHINGTON. THIS WOULD FORCE THE
CENTER OF THE RIDGE OFF TO THE EAST AND RESULT IN INCREASING
SOUTHWEST FLOW ACROSS OUR AREA AS WE MOVE INTO TUESDAY NIGHT AND
NEXT WEDNESDAY. AHEAD OF THIS SYSTEM HIGH LEVEL CLOUDS SHOULD START
TO INCREASE AS SHOULD SOUTHWEST WINDS ESPECIALLY OVER THE WESTERN
PORTIONS OF THE AREA. A BLEND OF FORECAST SOUNDINGS...MEX AND ECMWF
MOS AS WELL AS GFS AND ECMWF BIAS CORRECTED GUIDANCE WAS USED FOR
TEMPS THROUGH THE PERIOD. HIGHS SHOULD START OUT NEAR NORMAL ON
SATURDAY THEN WARM TO ABOUT 6-8 DEGREES ABOVE NORMAL BY TUESDAY. &&

.AVIATION...FOR MCCARRAN...SOUTHWEST TO AT TIMES SOUTH WINDS ARE
EXPECTED THROUGH WEDNESDAY EVENING. WINDS SHOULD REMAIN GUSTY
REACHING 15-25 KTS UNTIL SOMETIME BETWEEN 10Z AND 14Z WEDNESDAY WHEN
WINDS SHOULD DECREASE TO 5-10 KTS. AROUND 20Z WEDNESDAY WINDS SHOULD
INCREASE ONCE AGAIN TO 10-14 KTS SUSTAINED WITH GUSTS OF 18-22 KTS.
A FEW CLOUDS AOA 25K FEET AT TIMES.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WINDS SHOULD FAVOR A SOUTHWEST TO WEST DIRECTION OVER
THE MOJAVE DESERT AND LINCOLN COUNTY TONIGHT AND A NORTH TO
NORTHWEST DIRECTION ACROSS ESMERALDA COUNTY AND WESTERN INYO COUNTY
AT SPEEDS OF 6-12 KTS WITH GUSTS TO 20 KTS. GUSTS OF 30-35 KTS ARE
EXPECTED THROUGH 10Z WEDNESDAY IN NORTHWEST SAN BERNARDINO COUNTY.
ISOLATED SHRA AND TSRA ARE POSSIBLE THROUGH 03Z WEDNESDAY IN AND
AROUND KBIH. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA
25K FEET ON WEDNESDAY. WINDS SHOULD FAVOR A SOUTHWEST TO WEST
DIRECTION AT 6-12 KTS WITH GUSTS TO 20 KTS.
&&

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

$$

WOLCOTT/STACHELSKI

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