Heavy Snow in Nevada, March 31, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
240 PM PST FRI MAR 31 2006

.SHORT TERM...
NEGATIVE TILT UPPER LOW NOW COMING ONSHORE WITH IMPRESSIVE RAINBAND
MOVING INTO THE CENTRAL VALLEY WITH CONVECTION FORMING AHEAD OF IT.
CONVECTION ALSO FIRING ACROSS WESTERN NV FROM HAWTHORNE NORTH TO
HUMBOLDT COUNTY. EXPECT THIS CONVECTION TO LAST INTO THE EVENING
HOURS WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS AS LIS ARE
NEAR -2C. FURTHER WEST...PRECIP BAND WILL MAKE IT INTO THE SIERRA BY
6 PM WITH MODERATE TO HEAVY SNOWFALL. EXPECT SNOWFALL RATES OF 1-2
INCHES PER HOUR AS THE BAND MOVES THROUGH. WARNINGS FOR TAHOE-LASSEN
ON TRACK. IN MONO COUNTY...COULD SEE LOW END ADVISORY AMOUNTS AS LOW
LIFTS OUT AND BAND IS EXPECTED TO WEAKEN THAT FAR SOUTH. HOWEVER...
GIVEN THE AMOUNTS THEY HAVE SEEN RECENTLY...WILL NOT ISSUE DOWN
THERE AS IT IS A LOW IMPACT EVENT.

IN WESTERN NV TONIGHT...IMPRESSIVE DYNAMICS AND INSTABILITY WILL
ALLOW FOR EASY SPILLOVER AND MUCH PREFER GFS QPF. NAM IS MUCH TOO
LIGHT DESPITE SHOWING SIMILAR MASS FIELDS TO GFS. ADVISORIES FOR
ZONES 3-5 STILL ON TRACK. LOCAL WARNING AMOUNTS ARE POSSIBLE IN THE
RENO FOOTHILLS AND NORTH VALLEYS...BUT NOT EXPECTED TO BE
WIDESPREAD. AS THE BAND MOVES EAST...EXPECT IT WILL WEAKEN AS
DYNAMICS SHIFT NORTH AS LOW SLOWLY WEAKENS.

SOMEWHAT OF A BREAK ON SATURDAY WITH TEMPS ABOUT 10 DEGREES BELOW
NORMAL BUT WILL SEE MID AND HIGH CLOUDS FROM NEXT SYSTEM
APPROACHING. THAT ONE IS EXPECTED TO HAVE A BETTER SUBTROPICAL TAP
WITH MORE PRE-FRONTAL MOISTURE. OVERRUNNING FOR SAT NIGHT INTO
SUNDAY FOR NORTHEAST CALIFORNIA WITH LIGHT AMOUNTS OF SNOW. SUN
NIGHT THE FRONT WILL BE CLOSE ENOUGH FOR SOME MODERATE RAIN/SNOW
FROM TAHOE NORTH AND EXTREME NW NEVADA. WITH AREA UNDER EXIT REGION
OF JET WITH GOOD SUBTROPICAL PLUME EXPECT MODEL QPF MAY BE SLIGHLTY
UNDERDONE AND PREFER NAM FOR SIERRA AT THIS TIME. STABILITY PROFILES
ALSO FAVOR SOME SPILLOVER INTO NEVADA AS RAIN WITH SNOW LEVELS
5500-6000 FEET. MONDAY WILL BE THE WORST AS THE FRONT MOVES THROUGH
WITH MORE SHOWERY PRECIP MONDAY NIGHT. WALLMANN

.LONG TERM...TUESDAY THROUGH FRIDAY...
ACTIVE AND PROGRESSIVE PATTERN CONTINUES THROUGH NEXT WEEK WITH THE
GFS THE MOST PROGRESSIVE OF THE MEDIUM RANGE MODELS.  LATEST
ENSEMBLE MEANS WOULD SUPPORT SLOWER TIMING BUT OVERALL LITTLE CHANGE
TO CURRENT FORECAST. EARLY NEXT WEEK A STRONG NERN PAC LOW WILL
DEVELOP SIMILAR TO WHAT WE ARE SEEING TODAY. BROAD DEEP LOW
APPROACHES THE WEST COAST MONDAY NIGHT AND MOVES INLAND TUESDAY.
EXPECT OVERRUNNING PRECIPITATION WITH THE EARLY WEEK SYSTEM MONDAY
AND COLD FRONT PASSAGE MONDAY NIGHT OR EARLY TUESDAY. TIMING OF WHEN
THE SYSTEM EXITS NV IS UNCERTAIN AS FASTER GFS INDICATES THE LOW
MOVING EAST WED WHILE ECMWF/UK ARE SLOWER. DEPENDING ON THIS TIMING
WE COULD SEE A BREAK IN THE PRECIPITATION THURSDAY WITH ANOTHER EPAC
LOW MOVING TOWARD THE COAST AGAIN FRIDAY. TEMPERATURES SHOULD BE
CLOSE TO CLOSE TOWARD THE END OF NEXT WEEK.  JAH

&&

.AVIATION...
MVFR TO IFR CONDITIONS WITH SNOW IN THE NORTHERN SIERRA TONIGHT.
LIFR POSSIBLE AFTER 03Z-09Z WITH SN TO +SN. MVFR TO IFR CONDITIONS
WESTERN VALLEYS WITH RAIN AND SNOW SHOWERS MOVING IN BY 03Z. EXPECT
PRECIPITATION IN WESTERN VALLEYS TO BEGIN AS RAIN OR RAIN/SNOW MIX
BUT QUICKLY CHANGE TO SNOW. EXPECT CONDS TO IMPROVE ACROSS THE
SIERRA AND WESTERN NV AFTER 12Z. JAH

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST SATURDAY FOR
      NVZ005.
     WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 AM PST
      SATURDAY FOR NVZ002.
     SNOW ADVISORY FROM 6 PM THIS EVENING TO 4 AM SATURDAY FOR
      NVZ003.

CA...WINTER STORM WARNING FROM NOON TODAY TO 4 AM PST SATURDAY
      FOR CAZ071.
     SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST SATURDAY FOR
      CAZ070.
     WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 10 AM PST
      SATURDAY FOR CAZ072.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RENO NV
700 AM PST FRI MAR 31 2006

CAZ070>073-NVZ001>005-011500-
SURPRISE VALLEY CALIFORNIA-LASSEN-EASTERN PLUMAS-
EASTERN SIERRA COUNTIES-GREATER LAKE TAHOE AREA-MONO-
MINERAL AND SOUTHERN LYON COUNTIES-GREATER RENO-CARSON CITY-
MINDEN AREA-WESTERN NEVADA BASIN AND RANGE INCLUDING PYRAMID LAKE-
NORTHERN WASHOE COUNTY-
700 AM PST FRI MAR 31 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE EASTERN SIERRA...
NORTHEAST CALIFORNIA AND WESTERN NEVADA.

.DAY ONE...TODAY

A PACIFIC STORM SYSTEM WILL BEGIN TO AFFECT THE AREA TODAY
THROUGH SATURDAY. A WINTER STORM WARNING IN EFFECT FOR THE GREATER
LAKE TAHOE AND NORTHEASTERN CALIFORINA FROM NOON TODAY TO 7 AM PST
SATURDAY. SEE THE LATEST WINTER WEATHER STATEMENT FROM FROM KREV/WWUS45 KRNO
WSWREV/ FOR ADDITIONAL INFORMATION.

A SNOW ADVISORY IN EFFECT FROM 4 PM THIS AFTERNOON TO 7 AM PST
SATURDAY FOR SURPRISE VALLEY CALIFORINA AND NORTHERN WASHOE COUNTY.
SEE THE LATEST WINTER WEATHER STATEMENT FROM KREV/ WWUS45 KRNOWSWREV/
FOR ADDITIONAL INFORMATION.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A WINTER STORM WARNING EFFECT TIL 7 AM PST SATURDAY MORNING FOR
THE GREATER LAKE TAHOE AREA AND NORTHEASTERN CALIFORNIA. SEE THE
LATEST WINTER WEATHER STATEMENT FROM KREV/ WWUS45 KRNOWSWREV/ FOR
ADDITIONAL INFORMATION.

A SNOW ADVISORY EFFECT TIL 7 AM PST SATURDAY MORNING FOR SURPRISE
VALLEY CALIFORNIA AND NORTHERN WASHOE COUNTY. SEE THE LATEST WINTER
WEATHER STATEMENT FROM KREV/ WWUS45 KRNOWSWREV/ FOR ADDITIONAL
INFORMATION.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER TO THE
NATIONAL WEATHER SERVICE.