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000
FXUS65 KVEF 171618
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
918 AM PDT FRI MAY 17 2013

.SYNOPSIS...BREEZY TO WINDY CONDITIONS WILL CONTINUE TODAY AS A
TROUGH OF LOW PRESSURE MOVES ACROSS THE REGION. THIS SYSTEM WILL
ALSO BRING SCATTERED SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS TO
AREAS NORTH OF LAS VEGAS THROUGH THIS EVENING. WARMER...DRIER...
AND CALMER CONDITIONS ARE EXPECTED AGAIN THIS WEEKEND...FOLLOWED BY
WINDS INCREASING AGAIN EARLY NEXT WEEK.
&&

.UPDATE...THE BAND OF CLOUDS MENTIONED IN THE PREVIOUS DISCUSSION
HAS SHIFTED TO MAINLY OVER THE EASTERN PORTION OF THE CWA...
GENERALLY LINCOLN COUNTY THEN SOUTH OF INTERSTATE 15 THIS MORNING.
THIS MAY HAMPER HEATING SOMEWHAT...BUT EXPECT BAND TO CONTINUE
SHIFTING EAST DURING THE DAY ALLOWING FOR HEATING THIS AFTERNOON.
SHOWERS/THUNDERSTORMS STILL LOOK GOOD MAINLY OVER THE NORTHERN
MOUNTAINS WHILE WINDS SHOULD REMAIN BELOW ADVISORY LEVELS. OVERALL
THE SHORT TERM FORECAST REMAINS ON TRACK AND DO NOT PLAN ON ANY
UPDATES THIS MORNING.
&&

.PREV DISCUSSION...
340 AM PDT FRI MAY 17 2013

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...THE INCOMING TROUGH WAS
CENTERED OVER CALIFORNIA THIS MORNING AND THE AXIS IS FORECAST TO BE
OVER CENTRAL AND SOUTHERN NEVADA BY THIS AFTERNOON. GUSTY SOUTHWEST
WINDS WERE PERSISTING ACROSS THE MOJAVE DESERT REGION BUT THE LATEST
HIGH RESOLUTION MODELS AND MOS GUIDANCE NOW INDICATE GUSTS WILL
REMAIN BELOW 40 MPH ACROSS NORTHWEST SAN BERNARDINO COUNTY. THE WIND
ADVISORY WAS CANCELLED ACCORDINGLY. A BAND OF MID AND HIGH CLOUDS
OVER MUCH OF THE FORECAST AREA WAS ENHANCING ALONG THE LEADING EDGE
OF THE SYSTEM AND WILL SLOWLY SHIFT TO THE EAST DURING THE DAY.
MOISTURE AND INSTABILITY ASSOCIATED WITH THE COLD POOL WAS WORKING
ITS WAY ACROSS NORTHERN INYO AND ESMERALDA COUNTIES EARLY THIS
MORNING. MODELS CONTINUE TO INDICATE THE POTENTIAL FOR SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN SIERRA AND
SOUTHERN GREAT BASIN. A FEW SHOWERS WILL ALSO BE POSSIBLE FOR THE
SPRING MOUNTAINS AND SHEEP RANGE. NO SIGNIFICANT CHANGES WERE MADE
TO POP VALUES AND WEATHER. TEMPERATURES SHOULD RUN ABOUT 8-10
DEGREES LOWER THAN THOSE OBSERVED THURSDAY.

AS THE TROUGH SHIFTS EAST TONIGHT...DRY NORTHWEST FLOW WILL DEVELOP
OVER THE REGION WITH TEMPERATURES CLIMBING A FEW DEGREES SATURDAY. A
SHORTWAVE TROUGH WILL THEN SLIDE FROM THE PACIFIC NORTHWEST ACROSS
THE NORTHERN GREAT BASIN AND INTERMOUNTAIN REGION SATURDAY NIGHT
THROUGH AND SUNDAY. THE MAIN INFLUENCE OF THE SYSTEM WILL BE FELT
SUNDAY NIGHT INTO MONDAY AS NORTH WINDS PUSH DOWN THROUGH SOUTHERN
NEVADA AND SURROUNDING AREAS...ESPECIALLY THE COLORADO RIVER VALLEY.

.LONG TERM...NOT MUCH CHANGE NEEDED TO THE EXTENDED AS MODELS REMAIN
IN FAIRLY GOOD AGREEMENT. A SHORTWAVE RIDGE WILL BUILD IN NORTH OF
THE REGION ON MONDAY AND RESULT IN BREEZY NORTH WINDS AS THE
NORTH/SOUTH SURFACE GRADIENT TIGHTENS. LOCATIONS DOWN ALONG THE
COLORADO RIVER VALLEY WILL SEE NORTH WINDS 15-30 MPH ON MONDAY.
TUESDAY WILL SEE LESS WIND AND WARMER TEMPERATURES WITH THE RIDGE
OVERHEAD...BUT A DEEP AREA OF LOW PRESSURE DROPPING DOWN OVER THE
PACIFIC NORTHWEST WILL QUICKLY RESULT IN WINDS PICKING BACK UP
ACROSS THE MOJAVE DESERT BY LATE TUESDAY AFTERNOON. THIS PATTERN IS
THEN EXPECTED TO STAY FAIRLY STAGNANT THROUGH THE WEEK...BUT
THURSDAY AND FRIDAY LOOK TO BE THE DAYS WITH STRONGEST WINDS AS THE
TROUGH DEEPENS OVER THE WESTERN US. A GRADUAL COOLING TREND IN
TEMPERATURES WILL OCCUR TUESDAY THROUGH FRIDAY AS THE TROUGH SLOWLY
SHIFTS SOUTH...BUT ONLY DOWN TO SEVERAL DEGREES BELOW NORMAL BY
FRIDAY.

.AVIATION...FOR MCCARRAN...SURFACE WINDS ARE EXPECTED TO REMAIN OUT
OF THE SOUTHWEST THROUGH THE DAY WITH MAX GUSTS UP TO 30KTS AND
AVERAGE GUSTS BETWEEN 20 AND 25KTS AS A LOW PRESSURE SYSTEM PASSES
OVER THE AREA. NO PRECIPITATION OR CLOUD COVERAGE THAT WOULD IMPACT
ARRIVAL RATES...WITH THE LOWEST CIGS EXPECTED AOA 12KFT DURING THE
LATE MORNING. WINDS WILL BEGIN TO DIMINISH IN THE EVENING...AND DROP
BELOW 10KTS BETWEEN 04Z AND 08Z.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SOUTHWEST WINDS OF 15-25 KNOTS WILL CONTINUE TODAY
ACROSS MUCH OF THE AREA EXCEPT INYO AND ESMERALDA AND CENTRAL NYE
COUNTIES AS A TROUGH OF LOW PRESSURE PASSES ACROSS THE REGION.
SCATTERED SHOWERS ARE EXPECTED TO REMAIN MAINLY OVER THE HIGHER
ELEVATIONS OF LINCOLN...CLARK...AND CENTRAL NYE COUNTIES. BASES AS
LOW AS 5K-8K FEET WILL BE POSSIBLE IN AND NEAR ANY SHOWERS.
OTHERWISE EXPECT MAINLY SCT-BKN CLOUDS AOA 18K-25K FEET WITH FEW-SCT
CLOUDS AS LOW AS 8K-12K FEET.
&&

.FIRE WEATHER...SOUTHWEST WINDS OF 15 TO 25 MPH CAN BE EXPECTED
ACROSS THE MOJAVE DESERT TODAY AS A LOW PRESSURE TROUGH MOVES THE
OVER THE REGION. THIS SYSTEM WILL PROVIDE LOWER TEMPERATURES AND
RELATIVE HUMIDITIES GENERALLY ABOVE 15 PERCENT. CALMER CONDITIONS
ARE EXPECTED OVER THE WEEKEND...HOWEVER CRITICAL FIRE CONDITIONS MAY
DEVELOP BY TUESDAY WITH THE BEGINNING OF A PROLONGED STRETCH OF
SOUTHWEST WINDS.
&&

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

$$

UPDATE...JENSEN
PREV DISCUSSION...ADAIR/KENNEDY

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