030 
FXUS65 KVEF 281005
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
305 AM PDT FRI MAR 28 2014

.SYNOPSIS...DRY CONDITIONS AND WARMING TEMPERATURES CAN BE EXPECTED 
TODAY THROUGH SATURDAY AHEAD OF A STORM SYSTEM WHICH WILL MOVE 
THROUGH THE AREA 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. ANOTHER STORM 
SYSTEM IS FORECAST TO MOVE IN EARLY NEXT WEEK. 
&&

.SHORT TERM...MODELS ARE IN GOOD AGREEMENT WITH THE OVERALL PATTERN 
THROUGH SUNDAY NIGHT. A RIDGE OF HIGH PRESSURE WILL TRAVERSE THE 
AREA TODAY AND TONIGHT INTO SATURDAY. THIS WILL LEAD TO DRY 
CONDITIONS AND A WARMING TREND. HIGH TEMPERATURES WILL BE WELL ABOVE 
NORMAL SATURDAY. THE RIDGE AXIS WILL SHIFT EAST OF THE AREA SATURDAY 
AFTERNOON AS A SHORTWAVE TROUGH APPROACHES THE COAST. WINDS WILL 
PICK UP ACROSS THE AREA LATE SATURDAY BUT THE LATEST MODEL GUIDANCE 
INCLUDING THE HI-RES MODELS INDICATES WINDS REMAINING BELOW ADVISORY 
LEVELS FOR THE MOST PART. I STILL THINK THERE IS SOME POTENTIAL FOR 
SOME PRETTY STRONG SOUTHWEST WINDS IN THE SIERRA AND SPRING 
MOUNTAINS LATE SATURDAY AFTERNOON AND EVENING. THIS SHORTWAVE WILL 
MOVE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY LEADING TO A CHANCE 
OF SHOWERS ACROSS THE NORTHERN PORTION OF THE FORECAST 
AREA...ESPECIALLY IN THE SIERRA SATURDAY NIGHT AND OVER LINCOLN 
COUNTY SUNDAY. THE HIGHER ELEVATIONS OF THE SIERRA MAY SEE A DECENT 
SHOT OF SNOWFALL BUT IMPACTS ARE EXPECTED TO BE LIMITED AT 
ELEVATIONS WITH ROADWAYS AND POPULATION. PORTIONS OF LINCOLN COUNTY 
COULD SEE AROUND TWO TENTHS OF AN INCH OF RAIN SUNDAY. LOCALLY 
BREEZY CONDITIONS ARE EXPECTED SUNDAY WITH WIND DIRECTION SHIFTING 
FROM SOUTHWEST TO WEST AND NORTHWEST. THIS SHORTWAVE WILL ALSO BRING 
SIGNIFICANT COOLING SUNDAY WITH TEMPERATURES GENERALLY DROPPING BACK 
TO BELOW NORMAL LEVELS. ZONAL FLOW WILL BRING DRY CONDITIONS SUNDAY 
NIGHT. 

.LONG TERM...MONDAY THROUGH FRIDAY NIGHT.

ANOTHER SYSTEM IS STILL EXPECTED TO IMPACT THE AREA FROM MONDAY 
THROUGH WEDNESDAY MORNING. A LARGE MID/UPPER LEVEL TROUGH IS 
EXPECTED TO APPROACH FROM THE WEST ON MONDAY ACCOMPANIED BY A COLD 
AREA OF LOW PRESSURE. THE MAIN IMPACT FOR MONDAY AFTERNOON THROUGH 
MONDAY NIGHT CONTINUES TO LOOK LIKE GUSTY WINDS AS A 130 KT+ JET 
STREAK AT 250 MB ROUNDS THE BASE OF THE TROUGH. 700 MB WINDS OFF THE 
GFS AND ECMWF CONTINUE TO SHOW WIDESPREAD 30-40 KT+ VALUES ACROSS 
OUR AREA AND MODEL 500 MB HEIGHTS SHOW A HYDRAULIC JUMP SIGNATURE TO 
THE LEE OF THE SOUTHERN SIERRA. THIS SHOULD RESULT IN GUSTY GRADIENT 
SOUTHWEST TO WEST WINDS ACROSS THE AREA WITH THE POTENTIAL FOR 
DOWNSLOPE WINDS TO THE LEE OF THE SOUTHERN SIERRA, SPRING MOUNTAINS 
AND POTENTIALLY THE WHITE MOUNTAINS. WIND HEADLINES OF SOME SORT MAY 
EVENTUALLY BE NEEDED. WITH THE RECENT DRY CONDITIONS BLOWING DUST 
WILL BE A CONCERN.

DESPITE AN IMPRESSIVE INFLUX OF MOISTURE, FAVORABLE LIFT FROM THE 
JET AND GOOD MID-LEVEL FORCING SHOULD BE ENOUGH TO SPREAD SOME 
SHOWERS ACROSS THE NORTHERN HALF OF THE AREA FROM MONDAY THROUGH 
WEDNESDAY MORNING. WITH THE COLD POOL ALOFT PASSING OVERHEAD, ENOUGH 
INSTABILITY MAY ALLOW FOR A FEW THUNDERSTORMS AS WELL MAINLY ON 
TUESDAY. 700 MB TEMPS AS LOW AS -8C ARE FORECAST, BUT MOST OF THE 
MOISTURE AND BEST FORCING SHOULD BE GONE BY THEN, SO SNOW LEVELS ARE 
ONLY FORECAST TO DROP TO 5000-5500 FEET ON AVERAGE WHEN PRECIP IS 
FORECAST. 

WHILE MONDAY SHOULD STILL SEE TEMPS NEAR NORMAL, HIGHS SHOULD BE 
ABOUT 6-10 DEGREES BELOW NORMAL FOR TUESDAY AND WEDNESDAY. THE ECMWF 
REMAINS THE COLDER MODEL AND WE KEPT A BLEND OF THIS WITH THE WARMER 
GFS FOR TEMPS.

BEHIND THE DEPARTING COLD UPPER LOW THE FLOW ALOFT SHOULD TRANSITION 
TO THE WEST ALLOWING FOR SOME MODERATION OF TEMPS FOR THURSDAY 
PUSHING THEM CLOSER TO NORMAL. MODELS SHOW ANOTHER MID/UPPER LEVEL 
TROUGH ARRIVING FOR LATE NEXT WEEK BUT SHOW A BIG SPREAD IN THE 
TIMING WITH THE ECMWF FASTER AND THE GFS AND GEM SLOWER. FOR NOW, WE 
WENT WITH A BLEND OF THE TWO BUT LEANED TOWARD THE SLOWER SOLUTION. 
WE BROUGHT IN THE POTENTIAL FOR SHOWERS TO OUR NORTHERN CWFA MAINLY 
STARTING ON THURSDAY NIGHT. WINDS WITH THIS NEXT SYSTEM DO NOT 
APPEAR AS STRONG AT THIS TIME AS THE JET IS NOT PROGGED AS STRONG.
&&

.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS 7-10 KTS WILL 
PERSIST THROUGH EARLY THIS MORNING. WINDS ARE EXPECTED TO DEVELOP 
AN  EASTERLY COMPONENT LATE THIS MORNING OR EARLY AFTERNOON BUT 
SPEEDS SHOULD BE GENERALLY LESS THAN 7 KTS. TYPICAL DRAINAGE 
SOUTH/SOUTHWEST WINDS ARE EXPECTED AGAIN TONIGHT. SCT-BKN HIGH 
CLOUDS THROUGH TONIGHT. 

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...LIGHT AND VARIABLE WINDS WINDS ACROSS MOST OF THE 
REGION THROUGH THIS MORNING GIVING WAY TO SOUTHWEST TO WEST WINDS OF 
10-20 KTS THIS AFTERNOON AND EVENING. TYPICAL LIGHT DRAINAGE WINDS 
TONIGHT INTO EARLY SATURDAY MORNING. AREAS OF GUSTY SOUTHWEST WINDS 
WILL DEVELOP LATE SATURDAY. SCT-BKN HIGH CLOUDS THROUGH SATURDAY 
MORNING. 
&&

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

&&

$$

HARRISON/STACHELSKI

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