Heavy Snow Warning 2, NWS Las Vegas, NV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1155 PM PST FRI MAR 16 2006

.SYNOPSIS...A COLD PACIFIC STORM MOVING INTO THE SOUTHERN GREAT
BASIN AND MOJAVE DESERT OVER THE WEEKEND WILL BRING SCATTERED RAIN
SHOWERS TO THE DESERTS AND SNOW TO THE MOUNTAINS THROUGH SUNDAY.
DRIER CONDITIONS ARE EXPECTED MONDAY AHEAD OF ANOTHER STORM SYSTEM
APPROACHING THE WEST COAST FOR TUESDAY.
&&

.UPDATE...6 INCHES OF SNOW WAS REPORTED THIS EVENING AT GOLDFIELD.
UPDATED TO CHANGE THE SNOW ADVISORY TO A HEAVY SNOW WARNING.

THE CIRCULATING CENTER OF THE INCOMING STORM WAS EVIDENT ON
SATELLITE IMAGERY OVER THE SAN JOAQUIN VALLEY OF CALIFORNIA THIS
EVENING THUNDERSTORMS WERE FIRING NEAR THIS FEATURE. DOPPLER RADAR
DETECTED SCATTERED SHOWERS PRECEDING THE LOW CENTER EXTENDING ACROSS
THE SAN BERNARDINO COUNTY DESERTS TO THE SPRING MOUNTAINS OF
SOUTHERN NEVADA. THE MOST SIGNIFICANT FEATURE FOR OUR FORECAST AREA
WAS THE DEFORMATION ZONE SETTING UP ACROSS CENTRAL
NEVADA...ESPECIALLY ESMERALDA COUNTY. THE 12Z NAM PICKED UP ON THIS
WELL AND SHOWS A PERSISTENT 700 MB CONVERGENCE ZONE REMAIN OVER
ESMERALDA COUNTY THROUGH SATURDAY MORNING THEN GRADUALLY SLIDING
EAST AND WEAKENING DURING THE DAY. DECIDED TO ISSUE A SNOW ADVISORY
FOR ESMERALDA AND CENTRAL NYE COUNTY UNTIL 4 PM SATURDAY AFTERNOON.
THE REST OF THE ADVISORIES STILL LOOK OKAY BUT DID DELAY THE ONSET
FOR LINCOLN COUNTY AND REDUCED THE EXPECTED SNOW ACCUMULATIONS. IT
APPEARS THE BEST FOCUSING MECHANISM FOR PRECIPITATION WILL BE THE
DEFORMATION ZONE OVER CENTRAL NEVADA WHILE THE REMAINDER OF THE AREA
WILL HAVE TO RELAY ON FAIRLY WIDESPREAD INSTABILITY SHOWERS. THE
UPDATED ZONE FORECAST AND WINTER WEATHER MESSAGE HAVE BEEN SENT. &&

.AVIATION...GUSTY SOUTHWEST WINDS ARE EXPECTED TO AFFECT ALL
CORRIDORS THROUGH 09Z BEFORE DIMINISHING. CLOUD COVERAGE WILL
INCREASE AND CEILING WILL LOWER AS WELL. THE NORTH END OF THE BEATTY
CORRIDOR WILL SEE THE WORST CONDITIONS THROUGH 18Z WITH HEAVY SNOW
AND CEILINGS BELOW 1000 FEET AGL AND THUNDERSTORMS POSSIBLE. THE
MORMON MESA CORRIDOR WILL SEE LOWER CEILINGS AROUND 4000 FEET AT THE
NORTH END TONIGHT. THE DAGGETT CORRIDOR WILL SEE CEILINGS DOWN TO
3000 FEET IN RAIN SHOWERS AND ISOLATED THUNDERSTORMS.

HEAVY SNOW FALL AND LOW IFR CONDITIONS WILL OCCUR IN TWEB ROUTE 405
NORTH OF BEATTY AND INTO KHTH WITH BETTER CONDITIONS WITH SNOW
SHOWERS INTO KRNO.

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

.PREV DISCUSSION...255 PM PST FRI MAR 16 2006...

SHORT TERM...THE STORM SYSTEM CONTINUES TO APPROACH THE AREA WITH
THE SOUTHERN ENERGY NOW LOCATED JUST SOUTH OF THE MONTEREY
CALIFORNIA AREA. PRECIP ASSOCIATED WITH THE SYSTEM HAS BEEN FALLING
OVER MUCH OF NORTHERN AND CENTRAL CALIFORNIA THRU THE DAY AND IS NOW
SPREADING INTO CENTRAL NEVADA AND SOUTHERN CALIFORNIA JUST NORTH AND
WEST OF THE FORECAST AREA. DOPPLER RADAR AND LIGHTNING DETECTION
SYSTEMS SHOW THUNDERSTORMS FIRING OVER PORTIONS OF NORTHERN NYE AND
WHITE PINE COUNTIES IN NEVADA AS WELL AS OVER KERN COUNTY IN
SOUTHERN CALIFORNIA. SATELLITE IMAGERY SHOWS SOME UNANTICIPATED
CLEARING TAKING PLACE OVER MUCH OF THE CWA ATTM HOWEVER...THESE
AREAS SHOULD BEGIN TO FILL IN ONCE AGAIN AS THE STORM BEGINS MOVING
INTO THE REGION. SHOWERS ARE EXPECTED TO SPREAD OVER MUCH OF THE
AREA OVERNIGHT WITH SOME MOUNTAIN LOCATIONS SEEING LIGHT TO MODERATE
SNOW. CURRENTLY NO THUNDERSTORMS ARE FORECAST IN THE DESERTS HOWEVER
WILL NEED TO WATCH FOR THIS POTENTIAL OVERNIGHT. BRIEF PERIODS OF
HEAVY SNOW IN AREA MTNS ARE POSSIBLE ESPECIALLY WHEN ASSOCIATED WITH
THUNDERSTORMS. WILL LET SNOW ADVISORIES RIDE AS THEY ARE...ALTHOUGH
THE TIMING APPEARS TO BE A LITTLE EARLY...ESPECIALLY FOR LINCOLN
CNTY...AND SNOW LEVELS ARE RUNNING RATHER HIGH AT THIS TIME (NEAR
7500-8000 FEET). EXPECT THAT AS THE COLD AIR MOVES IN...SNOW LEVELS
WILL LOWER DRAMATICALLY OVERNIGHT AND SKIES WILL BECOME MOSTLY
CLOUDY. RAIN AND SNOW SHOWERS ARE EXPECTED THROUGH MUCH OF THE
WEEKEND WITH HIGH TEMPERATURES RUNNING AT LEAST 10 DEGREES BELOW
NORMAL BOTH SATURDAY AND SUNDAY. STORM TOTAL SNOW ACCUMULATIONS OF
UP TO 12 INCHES ARE POSSIBLE IN SOME FAVORED MOUNTAIN LOCATIONS BY
THE TIME THE STORM EXITS THE AREA EARLY MONDAY.

LONG TERM...WEAK SHORTWAVE RIDGE WILL BUILD OVER THE AREA ON MONDAY
AHEAD OF THE NEXT IN A SERIES OF PACIFIC LOW PRESSURE SYSTEMS TO
AFFECT THE REGION. GFS CONTINUE TO HAVE DIFFICULTLY IN WHERE TO TAKE
THIS LOW...BUT THE CONSENSUS SEEMS TO BE ACROSS NORTHERN PARTS OF
CALIFORNIA AND NEVADA. 12Z GFS RUN KEPT THE LOW CLOSED AS IT CROSSED
THE NORTHERN GREAT BASIN AND BRING DECENT QPF AMOUNTS TO THE CWA.
THE 18Z RUN NOW IS MORE PROGRESSIVE AS AN OPEN WAVE WITH LOWER QPF
AMOUNTS. OVER THE PAST SEVERAL DAYS THE 18Z GFS RUN HAS BEEN WILDLY
DIFFERENT AND SEEMS TO GO BACK ON THE 00Z RUN. WILL LEAN MORE WITH
THE 12Z GFS RUN AND THE EURO WHICH ARE FAIRLY SIMILAR AND BUMP THE
POPS OVER THE CWA TO HIGH CHANCE AMOUNTS. THE MODELS DO HAVE SOME
AGREEMENT THAT RIDGING WILL DEVELOP OVER THE AREA WEDNESDAY AND
THURSDAY WITH DRIER CONDITIONS AND WARMER TEMPERATURES. GFS DOES
SHOW ANOTHER LOW OFF THE PACIFIC NORTHWEST COAST BY SATURDAY AND
THIS WILL BE SOMETHING TO WATCH FOR FUTURE SHIFTS.
&&

.VEF WATCHES/WARNINGS/ADVISORIES...
.NV...HEAVY SNOW WARNING IN EFFECT FOR ZONE 14 UNTIL 4 PM PST
      SATURDAY. SNOW ADVISORY IN EFFECT UNTIL 4 AM PST SUNDAY FOR
      ZONE 15. SNOW ADVISORY FOR ZONES 18 AND 19 FROM 1 AM PST
      SATURDAY UNTIL 4 AM PST SUNDAY.
.AZ...SNOW ADVISORY FOR ZONE 1 FROM 2 AM MST SATURDAY UNTIL 5 AM MST
      SUNDAY.
.CA...SNOW ADVISORY FOR ZONE 26 FROM 6 PM PST THIS EVENING UNTIL 4
      AM PST SATURDAY MORNING.

SALMEN/GORELOW

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