641 
FXUS65 KVEF 140443 AAA
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
943 PM PDT SUN MAY 13 2012

.SYNOPSIS...AN AREA OF LOW PRESSURE WILL MOVE ACROSS NORTHERN 
CALIFORNIA AND NEVADA MONDAY AND TUESDAY RESULTING IN AREAS OF 
STRONG SOUTHERLY WINDS. LIGHTER WINDS ARE EXPECTED WEDNESDAY UNDER 
WEAK HIGH PRESSURE. PERSISTENT SOUTHWEST FLOW WILL BRING AN EXTENDED 
PERIOD OF BREEZY CONDITIONS THURSDAY THROUGH SATURDAY. DRY 
CONDITIONS AND ABOVE NORMAL TEMPERATURES CAN BE EXPECTED THROUGH 
THE WEEK. 
&&

.UPDATE...NARROW BAND OF CIRRUS ASSOCIATED WITH LOW OFF THE NORTHERN 
CALIFORNIA CONTINUES TO DISSIPATE AND MOVE EAST THIS EVENING. THE 
UPPER LOW WILL SLOWLY MOVE OVER NORTHERN CALIFORNIA TOMORROW AND BE 
OVER NORTHERN NEVADA TUESDAY. IT WILL REMAIN DRY WITH ABOVE NORMAL 
TEMPERATURES THE NEXT SEVERAL DAYS. HOWEVER...IT WILL BE BECOME 
BREEZY IN OUR NORTHWEST AREAS TOMORROW...THEN MORE ACROSS SOUTHEAST 
NEVADA AND NORTHWEST ARIZONA TUESDAY. WILL MAKE NO CHANGE TO 
EXISTING RED FLAG WARNING AND FIRE WEATHER WATCH.
&&

.PREV DISCUSSION...
315 PM PDT SUN MAY 13 2012

.SHORT TERM...A CLOSED UPPER LOW WILL MOVE INTO NORTHERN CALIFORNIA 
MONDAY. SOME HIGH CLOUDS WILL BE SEEN AHEAD OF THE LOW OVER OUR AREA 
TONIGHT. THE MAIN CONCERN WITH THE LOW IS INCREASING SOUTHERLY WINDS 
BY MONDAY AFTERNOON. THIS IS A GOOD SET UP FOR STRONG SOUTHERLY 
WINDS IN THE OWENS VALLEY ENHANCED BY DIURNAL UPVALLEY WINDS. THE 
OTHER AREA OF STRONG WINDS INDICATED BY THE MODELS IS ESMERALDA 
COUNTY. I EXPECT BREEZY TO WINDY CONDITIONS IN BOTH AREAS BUT 
OVERALL THE WINDS SHOULD REMAIN BELOW ADVISORY CRITERIA. THE LOW IS 
EXPECTED TO MOVE ACROSS NEVADA TUESDAY WITH THE MAIN AREA OF STRONG 
WINDS SHIFTING TO MOHAVE COUNTY. AGAIN IT LOOKS LIKE WIND SPEEDS 
WILL REMAIN JUST BELOW ADVISORY LEVELS. OVERALL THE WINDS SHOULD BE 
LIGHTER WEDNESDAY AS A SHORTWAVE RIDGE MOVES OVER THE AREA. 
OTHERWISE...HOT AND DRY CONDITIONS WILL CONTINUE THROUGH THE SHORT 
TERM WITH HIGH TEMPERATURES NEAR 100 DEGREES IN LAS VEGAS MONDAY 
THROUGH WEDNESDAY. 

.LONG TERM...THE EARLY EXTENDED WILL BE DOMINATED BY A 
PACIFIC TROUGH THAT IS FORECAST TO SHIFT ACROSS THE AREA IN THE 
THURSDAY TO FRIDAY TIME FRAME. THE GFS/ECMWF HAVE TRENDED WEAKER 
WITH THE TROUGH BUT THE ECMWF REMAINS THE DEEPER SOLUTION OF THE 
TWO. THE MAJORITY OF THE ENSEMBLE MEMBERS HAVE TRENDED WEAKER AS 
WELL. THE GEM IS THE LONE HOLDOUT IN DEVELOPING A CLOSED LOW OVER 
SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. THE GFS...BASED ON ITS 
MORE PROGRESSIVE PATTERN...WOULD BRING GUSTY WINDS INTO THE AREA 
QUICKER AND FOR A BRIEFER PERIOD. THE ECMWF/GEM WOULD CREATE MORE 
CONCERN FOR FIRE WEATHER DUE TO LONGER DURATION SOUTHWEST FLOW AND 
MAXIMUM HEATING AND MINIMUM RH TIMING. THE LATEST FORECAST BASICALLY 
USES A BLEND OF THE GFS/ECMWF TO SHOW BREEZY CONDITIONS ON THURSDAY 
FOLLOWED BY COOLING ON FRIDAY. WESTERLY FLOW IS FORECAST FOR 
SATURDAY WITH MODELS SHOWING WEAK UPPER EMBEDDED DISTURBANCES IN THE 
FLOW. RIDGING WORKS ITS WAY BACK INTO THE WEST FOR SUNDAY BRINGING 
LIGHT WINDS AND THE BEGINNING OF A WARMING TREND. 
&&

.AVIATION...FOR MCCARRAN...AN AREA OF LOW PRESSURE WILL MOVE INTO 
NORTHERN CALIFORNIA ON MONDAY BUT NO SIGNIFICANT WEATHER IS EXPECTED 
OVER THE NEXT 24 HRS AT THE TERMINAL. WINDS SHOULD GENERALLY FOLLOW 
A TYPICAL DIURNAL PATTERN THROUGH MONDAY MORNING THEN INCREASE OUT 
OF THE EAST SOUTHEAST UP TO 10KTS IN THE AFTERNOON. CLOUD COVER WILL 
BE LIMITED TO OCCASIONAL HIGH CLOUDS THROUGH MONDAY AFTERNOON.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...AN AREA OF LOW PRESSURE WILL MOVE INTO NORTHERN 
CALIFORNIA ON MONDAY RESULTING IN AN INCREASE IN SOUTHERLY WINDS IN 
THE OWENS VALLEY AND ESMERALDA/CENTRAL NYE COUNTIES IN THE 
AFTERNOON. WIND GUSTS APPROACHING 35KTS ARE POSSIBLE IN THESE AREAS. 
ELSEWHERE...NO SIGNIFICANT WEATHER IS EXPECTED OVER THE NEXT 24 HRS. 
CLOUD COVER SHOULD BE LIMITED TO OCCASIONAL HIGH CLOUDS EXCEPT FOR A 
A FEW CU OVER THE SOUTHERN SIERRA. 
&&

.FIRE WEATHER...STRONG SOUTHERLY WINDS WILL DEVELOP BY MONDAY 
AFTERNOON IN SOME AREAS AS A LOW PRESSURE SYSTEM MOVES INTO NORTHERN 
CALIFORNIA. THE OWENS VALLEY AND ESMERALDA COUNTY WILL LIKELY SEE 
WIND GUSTS FROM 35 TO 40 MPH WHILE RELATIVE HUMIDITY BOTTOMS OUT IN 
THE SINGLE DIGITS. A RED FLAG WARNING HAS BEEN ISSUED FOR THOSE 
AREAS. ALTHOUGH DRY CONDITIONS WILL BE SEEN ELSEWHERE...THE WINDS 
ARE EXPECTED TO REMAIN BELOW RED FLAG CRITERIA. STRONG SOUTH TO 
SOUTHWEST WINDS WILL LIKELY DEVELOP TUESDAY AFTERNOON ACROSS MUCH OF 
MOHAVE COUNTY AS THE LOW PRESSURE SYSTEM MOVES INTO NEVADA. A FIRE 
WEATHER WATCH HAS BEEN ISSUED. 
&&

.VEF WATCHES/WARNINGS/ADVISORIES...
NV...RED FLAG WARNING FROM NOON TO 8 PM PDT MONDAY FOR NVZ460. 
AZ...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY  
     EVENING FOR AZZ102.
CA...RED FLAG WARNING FROM NOON TO 8 PM PDT MONDAY FOR CAZ226.
&&

$$

HARRISON/SALMEN

HTTP://WEATHER.GOV/LASVEGAS