Winter Storm in California, March 2 to 3, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
950 PM PST THU MAR 2 2006

.SYNOPSIS...A LOW PRESSURE SYSTEM IS APPROACHING THE CENTRAL
CALIFORNIA COAST AND IS BRINGING SNOW TO THE HIGHER ELEVATIONS OF
THE SIERRA AND SOME BREEZY WINDS THERE. CLOUDS WILL OVER SPREAD THE
ENTIRE AREA AREA BY TOMORROW AFTERNOON WITH SNOW SHOWERS OVER THE
HIGHER ELEVATIONS OF ESMERALDA...INYO AND NORTHERN LINCOLN COUNTIES.
GUSTY SOUTHWEST WINDS WILL OCCUR OVER MOST LOCATIONS AS WELL FRIDAY.
THE WEEKEND WILL SEE A DECREASE IN CLOUD COVER AND WARMER
TEMPERATURES.
&&

.UPDATE...FETCH OF LOW LEVEL MOISTURE FROM SHORTWAVE THAT MOVED INTO
NORTHERN CALIFORNIA LAST EVENING STEADILY WORKED SOUTHEAST TODAY.
RADAR AND SURFACE OBSERVATIONS INDICATING LIGHT RAIN ACROSS THE
SOUTHERN SAN JOAQUIN VALLEY WITH MOISTURE BUILDING UP ON THE WESTERN
SLOPE OF THE SOUTHERN SIERRA. THE SECONDARY SHORTWAVE NOW GETTING
ITS ACT TOGETHER WITH RAIN ALONG THE NORTHWEST COAST OF CALIFORNIA
WITH SOUTHERN EXTENSION OF FRONTAL BAND APPROACHING THE CENTRAL
COAST. AT THIS TIME MAIN SHORTWAVE 280 MILES WNW OF MONTEREY PROGGED
TO REACH THE CENTRAL CALIFORNIA COAST FRIDAY MORNING THEN BEGIN TO
WEAKEN AND LIFT NORTHEAST ACROSS THE SOUTHERN SIERRA LATE MORNING
AND BE OVER CENTRAL NEVADA LATE FRIDAY AFTERNOON. TROUGH TAKES ON A
SLIGHT NEGATIVE TILT WITH DEEP LAYERED UPWARD FORCING ACROSS
SOUTHERN SIERRA AND CENTRAL NEVADA SO HIGHEST POPS CONCENTRATED
ACROSS THOSE ZONES. MOISTURE BECOMING MORE LIMITED ACROSS FAR
SOUTHERN NEVADA...EASTERN CALIFORNIA AND NORTHWEST ARIZONA. THE
SOUTHERN ZONES WILL BE IMPACTED MORE BY GUSTY SOUTHWEST WINDS.
UPDATE THIS EVENING DEALS WITH TIMING OF CLOUD COVER. SKIES WILL
REMAIN MOSTLY CLEAR REST OF TONIGHT WITH WITH INCREASE DELAYED UNTIL
AFTER LATE MORNING FOR SOUTHERN NEVADA.
&&

.PREV DISCUSSION...310 PM PST THU MAR 2 2006...WENT AHEAD AND
TRIMMED THE PRECIPITATION FORECAST TO REMOVE POPS FROM CLARK COUNTY
INCLUDING THE SOUTHERN MOUNTAINS FOR FRIDAY. MODEL RUNS STAYING
CONSISTENT KEEPING THE BULK OF THE MOISTURE AND QPF IN THE SIERRA
AND NORTH PART OF CWA. TODAY DID NOT SEE THE EXPECTED STRONG
DOWNSLOPE WINDS IN THE SIERRA. SOME WAVE ACTION WAS REPORT IN THE
NORTH PART OF THE OWENS VALLEY BY THE T-REX AIRCRAFT WHILE A FEW WEB
CAMS DID SHOW SOME DUST BEING BLOWN ALOFT. WEEKEND WILL SEE THE
QUICK DEPARTURE OF THE TROUGH AND SOME SLIGHT BUILDING OF A RIDGE IN
ITS WAKE BEFORE THE APPROACH OF ANOTHER BIG SYSTEM FOR THE LONG TERM
PERSON TO DEAL WITH.

.LONG TERM...SOUTHWEST FLOW ALOFT IS FORECAST OVER THE AREA EARLY
SUNDAY AHEAD OF A STRONG LOW PRESSURE SYSTEM OFF THE PACIFIC NW
COAST. TEMPERATURES OVER THE CWA SHOULD WARM SEVERAL DEGREES OVER
SATURDAY HIGHS UNDER THE SOUTHWESTERLY FLOW. AN IMPULSE MOVES AROUND
THE BASE OF LOW AND ACROSS THE AREA EARLY MONDAY. IT IS FORECAST TO
IMPACT THE SIERRA WHILE LOCATIONS FURTHER EAST ARE MOSTLY SHADOWED.
THE LATEST GFS QPF NUMBERS PRODUCE SLIGHTLY MORE THAN A HALF INCH OF
LIQUID ON THE SIERRA EAST SLOPES. BASED ON 700 MB FORECASTED TEMPS
FOR THE SIERRA...SNOW LEVELS SHOULD BE AROUND 5500 TO 6000 FEET
EARLY MONDAY AND DROP ANOTHER 1000 FEET THROUGH THE DAY. ALSO AHEAD
OF THE SYSTEM...WILL HAVE TO WATCH FOR POTENTIAL MOUNTAIN WAVE
ACTIVITY AS 30+ KT WINDS AT 600MB ARE FORECAST. THE MAIN LOWS OPENS
UP AND WEAKENS AS IT MOVES INLAND OVER WASHINGTON LATER MONDAY.
ENERGY WITHIN THE SOUTHERN REACHES OF THE TROUGH STRENGTHENS AND
MOVES THROUGH THE CWA TUESDAY/TUESDAY NIGHT. THIS WILL LIKELY GIVE A
CHANCE FOR SHOWERS TO NEARLY ALL OF THE FORECAST AREA. HAVE OPTED TO
SLOWLY INCREASE POPS FROM WEST TO EAST MONDAY NIGHT THRU TUESDAY
NIGHT. HOWEVER...DID NOT DO ANYTHING DRASTIC AS DIFFERENCES IN
TIMING AND STORM LOCATION WILL LIKELY CHANGE OVER THE NEXT SEVERAL
MODEL RUNS. AFTER REACHING A PLATEAU ON SUNDAY...TEMPS WILL SLOWLY
DECREASE THROUGH THE WEEK AS A COOLER AIRMASS TAKES HOLD.
&&

.AVIATION...STRONG SOUTHWESTERLY FLOW WILL CONTINUE OVER THE
SOUTHERN SIERRA MOUNTAINS THROUGH THE NIGHT AND TURBULENCE
ASSOCIATED WITH MOUNTAIN WAVE ACTIVITY WILL CONTINUE TO BE A CONCERN
IN THE LEE OF THE SIERRA. CLOUD COVER ASSOCIATED WITH AN APPROACHING
STORM SYSTEM WILL BEGIN SPREADING INTO THE NORTHWEST FORECAST AREA
TONIGHT WITH MOUNTAIN TOPS IN THE SIERRA BECOMING OBSCURED. ON
FRIDAY...STRONGER SOUTHWEST WINDS WILL SURFACE BY LATE MORNING IN
THE LAS VEGAS VALLEY WITH GUSTS AT KLAS AROUND 30 KTS. ISOLATED
SHOWERS WILL DEVELOP ACROSS THE BEATTY CORRIDOR AFTER 18 UTC FRIDAY
WITH CEILINGS THROUGH THE CORRIDOR BETWEEN 060-080 MSL.

TAFS AND TWEBS ADEQUATELY DESCRIBE EXPECTED WEATHER CONDITIONS. SEE
TAFS FOR KLAS...KVGT...KDRA...KBIH...KDAG...KEED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&

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

&&

PIERCE/JACQUES/SALMEN

HTTP://WEATHER.GOV/LASVEGAS