901 
FXUS65 KVEF 132218
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
318 PM PDT THU MAR 13 2014

.SYNOPSIS...AN UPPER LEVEL LOW WILL MOVE INTO ARIZONA TONIGHT AND 
DRIER AIR WILL WORK INTO THE AREA OVERNIGHT RESULTING IN A DECREASE 
IN CLOUD COVER. HIGH PRESSURE ALOFT WILL BUILD INTO THE AREA OVER 
THE WEEKEND ALLOWING FOR WARM AND DRY CONDITIONS. A TROUGH IS 
EXPECTED TO DIVE INTO THE REGION MONDAY INTO TUESDAY BRINGING A 
COOLING TREND ALONG WITH BREEZY CONDITIONS.
&&

.SHORT TERM...WITH SO MUCH DRY AIR IN THE LOW LEVELS ANY MEANINGFUL 
SHOWERS HAVE BEEN HARD TO COME BY IN OUR AREA THIS AFTERNOON. THE 
LATEST RADAR INDICATES VERY LIGHT RETURNS MAINLY OVER EASTERN MOHAVE 
COUNTY AND IT APPEARS DOUBTFUL THAT MUCH IF ANY OF THIS IS REACHING 
THE GROUND. THE LATEST SATELLITE IMAGERY ALSO SHOWS LESS ENHANCED 
CLOUD COVER OVER SOUTHERN SAN BERNARDINO COUNTY. IT IS POSSIBLE THAT 
A FEW SHOWERS MAY STILL DEVELOP OVER EASTERN MOHAVE COUNTY THIS 
EVENING AHEAD OF THE CENTER OF THE UPPER LEVEL LOW (WHICH AT THE 
PRESENT WAS OVER SOUTHWESTERN SAN BERNARDINO COUNTY ON WATER VAPOR) 
SO A SLIGHT CHANCE WAS LEFT IN THERE FOR THE REMAINDER OF THE NIGHT. 
ELSEWHERE IT SHOULD STAY DRY. OVERALL CLOUDS SHOULD DECREASE THIS 
EVENING INTO TONIGHT FROM WEST TO EAST AS THE LOW PULLS AWAY. LOWS 
TONIGHT MAY DROP A BIT IN SOME LOCATIONS FROM LAST NIGHT GIVEN WE 
SHOULD HAVE LESS CLOUD COVER AROUND.

A WARMING TREND IS EXPECTED FRIDAY INTO SATURDAY AS A RIDGE ALOFT 
BUILDS INTO SOCAL. ENERGY DROPPING DOWN THE ROCKIES ON SATURDAY 
MORNING WILL HELP NORTH-SOUTH SURFACE PRESSURE GRADIENTS TO TIGHTEN 
IN OUR AREA WHICH SHOULD INCREASE WINDS IN THE COLORADO RIVER VALLEY 
BY LATE SATURDAY MORNING. WE MAY GET CLOSE TO LAKE WIND ADVISORY 
CRITERIA IN THE LAUGHLIN-BULLHEAD CITY AREA SATURDAY AFTERNOON BUT 
IT LOOKS LOCALIZED AT THIS TIME. SURFACE PRESSURE GRADIENTS ARE 
FORECAST TO RELAX SATURDAY NIGHT INTO SUNDAY RESULTING IN LIGHTER 
WINDS. OVERALL IT SHOULD BE A NICE WEEKEND WITH A DECENT AMOUNT OF 
SUNSHINE AND HIGH TEMPS 8-12 DEGREES ABOVE NORMAL. TEMPS WERE MAINLY 
A BLEND OF THE CONS MODELS AND CONTINUITY WITH SOME MINOR TWEAKS 
BASED ON LOCAL TRENDS AND STATISTICAL GUIDANCE.

.LONG TERM...MONDAY THROUGH THURSDAY...MODELS ARE IN GOOD AGREEMENT 
THAT THE RIDGE THAT WILL BE SITUATED OVER THE REGION THIS WEEKEND 
WILL BEGIN TO FLATTEN OUT ON MONDAY AS A TROUGH PUSHES THROUGH THE 
NORTHERN GREAT BASIN. THE MAIN IMPACT THIS TROUGH WILL HAVE ON OUR 
FORECAST AREA WILL BE COOLER TEMPERATURES AS WELL AS THE POTENTIAL 
FOR PERIODS OF GUSTY WINDS ON TUESDAY AS THE SYSTEM MOVES THROUGH. 
THE 12Z OPERATIONAL MODELS DIFFER SLIGHTLY ON THE EXACT DETAILS OF 
THIS SYSTEM. THE GFS BRINGS THE TROUGH THROUGH THE REGION MUCH 
QUICKER THAN THE ECMWF.  THE ECMWF ALSO BRINGS COOLER AIR INTO THE 
REGION...WITH TEMPERATURES AT THE 700 MB LEVEL ABOUT 10 DEGREES 
CELSIUS COLDER THAN THE GFS FOR TUESDAY.  I LOWERED THE TEMPERATURES 
SLIGHTLY EACH DAY IN THE LONG TERM PERIOD TO BE BETTER IN LINE WITH 
THE LATEST GUIDANCE. THE MODELS AGREE THAT ANY PRECIPITATION 
ASSOCIATED WITH THIS SYSTEM LOOKS TO BE WELL NORTH OF OUR FORECAST 
AREA.  THE MODELS GENERALLY AGREE THAT A RIDGE WILL BUILD BACK INTO 
THE REGION FOR THE END OF THE LONG TERM...HOWEVER THEY DISAGREE ON 
THE EXACT TIMING.   
&&

.AVIATION...FOR MCCARRAN...WINDS SHOULD MAINLY BE 6 KTS OR LESS AND 
FAVOR TYPICAL DIURNAL DIRECTIONAL TRENDS THROUGH FRIDAY EVENING. 
DECREASING CLOUDS TONIGHT AOA 10-15K FEET. A CLEAR SKY LATE MID TO 
LATE FRIDAY MORNING SHOULD GIVE WAY TO FEW-SCT CLOUDS AOA 20K FEET 
BY FRIDAY AFTERNOON.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...WINDS SHOULD FAVOR TYPICAL DIURNAL DIRECTIONAL TRENDS 
THROUGH FRIDAY EVENING AT 10 KTS OR LESS. THE EXCEPTION WILL BE IN 
THE COLORADO RIVER VALLEY BELOW HOOVER DAM WHERE SUSTAINED NORTH 
WINDS OF 8-16 KTS ARE EXPECTED ON FRIDAY WITH GUSTS TO 20 KTS. 
SCT-BKN CLOUDS AOA 8K-16K FEET TONIGHT IN MOHAVE COUNTY WITH 
ISOLATED SHOWERS POSSIBLE MAINLY BEFORE 12Z FRIDAY. OTHERWISE EXPECT 
DECREASING CLOUDS TONIGHT. A BAND OF CLOUDS AOA 20K FEET SHOULD PUSH 
ACROSS SOUTHERN NEVADA AND INYO COUNTY ON FRIDAY IN THE LATE MORNING 
AND AFTERNOON.
&&

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

$$

SHORT TERM/AVIATION...STACHELSKI
LONG TERM...METZGER

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