179 
FXUS65 KVEF 280350
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
850 PM PDT THU MAR 27 2014

.SYNOPSIS...WARMING TEMPERATURES WILL COMMENCE FRIDAY AND SATURDAY 
AHEAD OF A STORM SYSTEM SATURDAY NIGHT INTO SUNDAY. THIS SYSTEM WILL 
BRING WITH IT INCREASING CLOUDS...WIND...AND CHANCES FOR 
PRECIPITATION IN THE SIERRA AND NORTHERN PORTIONS OF THE FORECAST 
AREA. AN ADDITIONAL STORM SYSTEM IS FORECAST TO MOVE IN EARLY NEXT 
WEEK. 
&&

.UPDATE....BRIEF CLEARING ACROSS THE AREA WILL BE REPLACED BY 
INCREASING HIGH CLOUDS CURRENTLY SPREADING ACROSS CENTRAL AND 
NORTHERN CALIFORNIA. MINOR CHANGES TO SKY AND WIND GRIDS WERE MADE 
THROUGH 15Z FRIDAY TO BRING IN LINE WITH RECENT OBSERVATIONS AND 
TRENDS OVER THE NEXT 12 HOURS. THE REST OF THE FORECAST LOOKS IN 
LINE WITH DETAILS IN THE PREVIOUS DISCUSSION.
&&

.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS 7-10 KTS WILL 
PERSIST OVERNIGHT UNDER A CLEAR SKY. WINDS ARE EXPECTED TO DEVELOP 
AN EASTERLY COMPONENT BY EARLY FRIDAY AFTERNOON BUT SPEEDS SHOULD BE 
GENERALLY LESS THAN 7 KTS.   

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...VARIABLE WINDS WINDS OF 5-15 KTS UNDER A MOSTLY CLEAR 
SKY OVERNIGHT CAN BE EXPECTED ACROSS MOST OF THE REGION. THE 
EXCEPTION REMAINS WESTERN SAN BERNARDINO COUNTY WHERE GUSTS TO 25 
KTS WILL GRADUALLY DIMINISH AFTER MIDNIGHT. LIGHT WINDS AREAWIDE 
FRIDAY MORNING WILL GIVE WAY TO SOUTHWEST TO WEST WINDS OF 10-20 KTS 
FRIDAY AFTERNOON AND EVENING.
&&

.PREV DISCUSSION...245 PM PDT

.SHORT TERM...TONIGHT THROUGH SUNDAY...MUCH QUIETER WEATHER TODAY 
WITH NORTHWEST FLOW DOMINATING THE WEATHER ACROSS THE SOUTHWEST. 
MAIN FEATURE OF NOTE IS AN AREA OF TERRAIN ENHANCED CLOUD COVER IN 
ASSOCIATION WITH SOME WEAK PASSING SHORTWAVE ENERGY.  FLAT HIGH 
PRESSURE RIDGE WILL NUDGE INTO THE FORECAST AREA TOMORROW WITH THE 
FLOW BECOMING MORE SOUTHWESTERLY BY SATURDAY. THIS WILL RESULT IN A 
WARMING TREND BEGINNING TOMORROW AND PEAKING ON SATURDAY WITH 
TEMPERATURES RISING 5-10 DEGREES ABOVE NORMAL BY SATURDAY AFTERNOON. 

IN ADDITION TO THE WARMING TREND...WINDS WILL ONCE AGAIN BE ON THE 
INCREASE LATE FRIDAY NIGHT INTO SATURDAY AHEAD OF OUR NEXT STORM 
SYSTEM. WINDS WILL FIRST PICK UP ACROSS THE SIERRA LATE FRIDAY AND 
THEN EXPAND TO THE SPRING MOUNTAINS BY SATURDAY MORNING. BREEZY TO 
WINDY CONDITIONS SHOULD OVERSPREAD MUCH OF THE FORECAST AREA BY 
SATURDAY AFTERNOON. THERE IS SOME POTENTIAL FOR HIGH WINDS ACROSS 
THE SIERRA AND SPRING MOUNTAINS ONCE AGAIN...HOWEVER...CURRENT HIGH 
RESOLUTION MODEL GUIDANCE ISNT SHOWING AN OVERLY IMPRESSIVE 
SIGNATURE FOR HIGH WINDS IN THE TYPICALLY FAVORED LOCATIONS....SO 
HAVE HELD OFF ON ANY HEADLINES. 

SATURDAY NIGHT...COLD FRONT WILL BEGIN TO APPROACH THE AREA AND MOVE 
ACROSS THE REGION OVERNIGHT. THIS SYSTEM IS VERY PROGRESSIVE AND 
WILL MOVE IN AND OUT VERY QUICKLY. NONETHELESS...IT IS VERY DYNAMIC 
WITH STRONG HEIGHT FALLS AHEAD OF THE SHORTWAVE AND A DECENT 
MOISTURE TAP. LOOKS LIKE THE SIERRA AND MUCH OF 
NYE...LINCOLN...ESMERALDA COUNTIES STAND A GOOD CHANCE AT PICKING UP 
MEASURABLE PRECIPITATION. EVEN NORTHERN CLARK AND MOHAVE COUNTIES 
MAY SEE A STRAY SHOWER OR TWO. SNOW LEVELS ABOVE 6K FT SHOULD LIMIT 
ANY IMPACTS RELATED TO SNOW...BUT THE SIERRA ABOVE 7K FT MAY SEE A 
FEW INCHES OF SNOW. THE COLD FRONT SHIFTS EAST SUNDAY WITH COOL BUT 
IMPROVING CONDITIONS EXPECTED SUNDAY AFTERNOON. 

.LONG TERM...THE NEXT TROUGH OF LOW PRESSURE WILL BE ADVANCING 
TOWARD THE REGION SUNDAY NIGHT THROUGH MONDAY. THIS IS EXPECTED TO 
LEAD TO YET ANOTHER PERIOD OF ENHANCED WINDS MONDAY INTO TUESDAY. 
12Z GUIDANCE HAS TRENDED A BIT WEAKER WITH WINDS COMPARED TO PRIOR 
RUNS...ESPECIALLY WITH THE DOWNSLOPE POTENTIAL OVER THE SIERRA/WHITE 
RANGES. I OPTED NOT TO MAKE DRASTIC CHANGES TO THE FORECAST THIS FAR 
OUT...ONLY TRENDING WINDS DOWN SLIGHTLY FROM THE PREVIOUS FORECAST. 
ALL THIS SAID IT STILL APPEARS TO BE A WINDY SYSTEM WITH AT LEAST 
SOME ADVISORY LEVEL WINDS. THE SYSTEM DOES STILL APPEAR TO BE QUITE 
COLD WITH 700MB TEMPERATURES DROPPING TO AROUND -7 TO -9 DEGREES 
OVER LAS VEGAS AS THE TROUGH AXIS MOVES OVERHEAD TUESDAY NIGHT. THIS 
SHOULD LEAD TO AT LEAST SOME SHOWER ACTIVITY EVEN THOUGH THE SYSTEM 
LACKS A SIGNIFICANT MOISTURE TAP BY THE TIME IT REACHES THE FORECAST 
AREA. I DID EXPAND CHANCES OF PRECIPITATION A BIT FURTHER 
SOUTH...GIVING A NOD TO THE MORE AGGRESSIVE ECMWF. THE COLD 
TEMPERATURES ALOFT COULD LEAD TO SOME PRETTY NIPPY TEMPERATURES FOR 
TUESDAY AND WEDNESDAY /AT LEAST FOR EARLY APRIL IN LAS VEGAS/. 
TEMPERATURES SHOULD BEGIN TO WARM AGAIN BY THURSDAY AS HIGHER 
PRESSURE BUILDS IN.
&&

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

&&

$$

UPDATE/AVIATION...ADAIR
PREV DISCUSSION...OUTLER/WOLCOTT

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