993
FXUS65 KVEF 032309
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
309 PM PST SUN MAR 3 2013

.SYNOPSIS...A LOW PRESSURE SYSTEM MOVING FROM CENTRAL CALIFORNIA
ACROSS SOUTHERN NEVADA TONIGHT WILL PRODUCE SCATTERED TO NUMEROUS
SHOWERS ACROSS CENTRAL AND SOUTHEAST NEVADA TROUGH EARLY MONDAY
MORNING. MILD CONDITIONS MONDAY AND TUESDAY WILL BE FOLLOWED BY A
STRONGER STORM BRINGING WINDY...COOLER AND SHOWERY WEATHER TO MUCH
OF THE REGION THE SECOND HALF OF THE WEEK.
&&

.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...SOUTHWEST WINDS WERE
RESPONDING ABOUT AS EXPECTED AHEAD OF THE INCOMING UPPER LOW MOVING
ACROSS CENTRAL CALIFORNIA. THE STRONGEST GUSTS WERE OCCURRING ACROSS
NORTHWEST SAN BERNARDINO COUNTY AND IN RED ROCK CANYON. THE LATEST
HIGH RES MODEL CROSS SECTIONS INDICATE GUSTS OVER 40 MPH SHOULD
CONTINUE IN RED ROCK CANYON UNTIL ABOUT 9-10 PM PST AND THE ADVISORY
WAS EXTENDED ACCORDINGLY. THOUGH GUSTS OVER 40 MPH HAVE YET TO
MATERIALIZE AT BARSTOW-DAGGETT AND TWENTYNINE PALMS...THE BELT OF
WINDS WILL SHIFT SOUTHWARD AHEAD OF THE UPPER LOW AND ASSOCIATED
SURFACE FRONT SLIDING ACROSS SOUTHERN NEVADA AND SURROUNDING AREAS
TONIGHT. SHOWERS LOOK LIKELY ACROSS LINCOLN COUNTY OVERNIGHT AS THE
MOISTURE BAND BECOMES FAIRLY CONCENTRATED OVER EAST CENTRAL NEVADA
AND POP VALUES WERE INCREASED TO ACCOUNT FOR THIS. NORTH BREEZES
WILL DEVELOP ACROSS MUCH OF THE REGION MONDAY AS THE SYSTEM QUICKLY
PULLS AWAY TO THE EAST. HIGH TEMPS WILL ALSO DROP SEVERAL DEGREES.

A RIDGE QUICKLY TRAVERSES THE REGION MONDAY AND MONDAY NIGHT THEN
SOUTHWEST FLOW INCREASES TUESDAY AND ESPECIALLY WEDNESDAY AS A MUCH
BROADER AND STRONGER PACIFIC LOW MOVES INTO THE WEST COAST. THIS
WILL LEAD TO ANOTHER ROUND OF GUSTY SOUTHWEST WINDS ACROSS THE
REGION WEDNESDAY AND SOME POTENTIAL FOR A STRONG DOWNSLOPE EVENT FOR
THE EAST SLOPES OF THE SOUTHERN SIERRA/OWENS VALLEY. WIND WILL BE
THE MAIN INITIAL CONCERN. MOISTURE ON THE SOUTHEAST PERIPHERY OF THE
SYSTEM WILL BE LIMITED INITIALLY BUT KEPT A CHANCE OF PRECIP OVER
NORTHERN INYO...ESMERALDA AND CENTRAL NYE COUNTIES WEDNESDAY
EVENING. LITTLE VARIATION IN TEMPERATURES IS EXPECTED TUESDAY AND
WEDNESDAY.

.LONG TERM...THURSDAY THROUGH SUNDAY...MEDIUM RANGE MODEL AGREEMENT
APPEARS TO HAVE DETERIORATED SLIGHTLY WITH THE LATEST 12Z GUIDANCE.
FEW CHANGES WERE MADE TO THE INHERITED FORECAST AND GENERALLY
BROAD-BRUSHED GRIDS STILL IN PLACE.

A LONGWAVE TROUGH WILL BE DIGGING SOUTH ALONG THE WEST COAST
THURSDAY. SOUTH-SOUTHWEST FLOW ACROSS THE AREA WILL BRING BREEZY
CONDITIONS TO MUCH OF THE AREA AS WELL AS INCREASE MID-HIGH CLOUDS.
AT THIS TIME WINDS THURSDAY LOOK TO BE AT OR JUST BELOW LEVELS SEEN
WEDNESDAY...AND NOT QUITE AS WIDESPREAD. THIS WOULD GIVE US WINDS
BELOW WIND ADVISORY LEVELS IN MOST LOCATIONS...THOUGH THERE IS THE
POTENTIAL FOR ADVISORY LEVEL WINDS...MAINLY ACROSS WESTERN SAN
BERNARDINO COUNTY AND THE SPRING MOUNTAINS. PRECIPITATION IS
EXPECTED TO DEVELOP ACROSS THE NORTHERN HALF OF THE FORECAST AREA
THROUGH THURSDAY/THURSDAY NIGHT...THEN TRANSITION TO THE EASTERN
HALF OF THE AREA FRIDAY AND SATURDAY...THEN TAPERING OFF FROM WEST
TO EAST. SNOW LEVELS MAY BRIEFLY DROP TO AS LOW AS 3000-4000K FEET
AS THE UPPER LEVEL LOW PASSES OVER/NEAR THE FORECAST AREA FRIDAY
NIGHT. OTHERWISE...SNOW LEVELS ARE EXPECTED TO REMAIN ABOVE
4000-4500 FEET DURING THE EVENT...WITH ACCUMULATING SNOWFALL
POSSIBLE ABOVE 4500 FEET. PINPOINTING PRECIP AMOUNTS REMAINS
DIFFICULT...BUT AREAS THAT HAVE THE BEST CHANCES OF RECEIVING PRECIP
WILL LIKELY SEE 0.10-0.40 INCHES OF LIQUID...WITH LOCALLY HIGHER
AMOUNTS...ESPECIALLY IN HIGHER TERRAIN OR WITH HEAVIER SHOWERS.
THESE AMOUNTS HAVE DECREASED COMPARED TO MODEL QPF AMOUNTS THAT WERE
ADVERTISED 24 HOURS AGO. MODELS DO INDICATE THE POTENTIAL FOR WEAK
CONVECTION WITH AREAS OF NEAR ZERO OR NEGATIVE LI`S...PRIMARILY AS
THE TROUGH/LOW MOVE OVER THE FORECAST AREA FRIDAY/FRIDAY NIGHT. AS
THE SURFACE LOW PUSHES TO THE EAST/SOUTHEAST FRIDAY NIGHT INTO
SATURDAY MORNING MODELS ARE PRODUCING A DECENT PRESSURE GRADIENT
ACROSS THE REGION WITH STIFF NORTH WINDS ACROSS MUCH OF THE FORECAST
AREA. THESE WINDS ALSO APPEAR TO NEARING ADVISORY LEVELS.
TEMPERATURES WILL DROP BELOW NORMAL THURSDAY THROUGH SATURDAY AND
LOOK TO BE ROUGHLY 15 DEGREES COOLER THAN THIS AFTERNOON. CONDITIONS
WILL GRADUALLY BEGIN TO IMPROVE SUNDAY AS HIGHER PRESSURE BUILDS
INTO THE REGION...THOUGH BREEZY CONDITIONS WILL BE POSSIBLE DOWN THE
COLORADO RIVER VALLEY.
&&

.AVIATION...FOR MCCARRAN...WINDS GUSTING TO 25-35 KTS WILL CONTINUE
INTO THIS EVENING...WITH OCCASIONAL BLOWING DUST AT OR NEAR THE
TERMINAL. SPEEDS WILL BEGIN TO SLOWLY DECREASE AFTER 02Z. BKN CLOUDS
BASES ARE GENERALLY EXPECTED FROM 10-12K FEET WITH SCATTERED LOWER
CLOUDS BETWEEN 6-10K FEET AT TIMES. WINDS ARE EXPECTED TO DECREASE
AROUND MIDNIGHT AND WILL BEGIN TO TURN TO THE NORTHEAST AS A SYSTEM
MOVES THROUGH THE REGION. CLEARING SKIES AND LIGHTER WINDS FAVORING
A NORTH/NORTHEAST DIRECTION ARE EXPECTED MONDAY.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GUSTY SOUTH TO SOUTHWEST WINDS WILL CONTINUE INTO THIS
EVENING. THE STRONGEST WINDS WILL BE ACROSS WESTERN SAN BERNARDINO
COUNTY...WHERE GUSTS TO AROUND 40 KTS WILL BE POSSIBLE. CLOUDS ARE
EXPECTED TO LOWER...PRIMARILY IN THE NORTH...TO 5-10K FEET...WITH
POSSIBLE SHOWERS. WINDS SPEEDS WILL DECREASE ACROSS THE REGION
OVERNIGHT...BEGINNING TO FAVOR A NORTHERLY DIRECTION MONDAY.
&&

.VEF WATCHES/WARNINGS/ADVISORIES...
NV...WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR NVZ019.
AZ...NONE.
CA...WIND ADVISORY UNTIL 4 AM PST MONDAY FOR CAZ523-525.
&&

$$

ADAIR/WOLCOTT

HTTP://WEATHER.GOV/LASVEGAS