Heavy Snow in California, March 22, 2002

WESTERN NEVADA AND EASTERN CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
225 AM PST FRI MAR 22 2002

EAST PACIFIC LOW VERY SLOWLY APPROACHING COAST THIS MORNING WITH
SOUTHERLY FLOW ALOFT INCREASING OVER AREA. ETA/AVN DIFFER ON TIMING
AND STRENGTH OF EMBEDDED SHORTWAVES. BASED ON TRENDS THE SLIGHTLY
SLOWER ETA WOULD APPEAR TO BE THE TIMING OF CHOICE WHILE THE AVN
HANDLING OF SHORTWAVE FEATURES MIGHT BE PREFERRED. FOR TODAY EXPECT
A CHANCE OF RAIN/SNOW FOR THE SIERRA WITH WINDY CONDITIONS MOST
AREAS. WILL FOREGO WIND ADVISORY AT THIS TIME AS SLOWER ETA SOLUTION
BRINGS STRONGEST WINDS THIS EVENING. EVEN MESOETA ONLY SUPPORTS WIND
GUSTS TO 45 MPH WHICH WILL PROBABLY HOLD TRUE FOR PLACES LIKE WASHOE
VALLEY AND IN THE FOOTHILLS OF THE SIERRA. AS THE STRONG WINDS ALOFT
WORK INTO NEVADA LATER TODAY...MODELS ARE DEPICTING STRONG SURFACE
CONVERGENCE IN ASSOCIATION WITH FORCING FROM UPPER JET MAXIMA
WORKING INTO SOUTHERN SIERRA/SOUTHERN NEVADA. THERE WILL LIKELY BE
SOME HIGH BASED SHOWERS EAST OF THE SIERRA. A COMBINATION OF CLOUDS/
LACK OF SUFFICIENT SURFACE HEATING AND THE SLIGHTLY SLOWER TIMING/
DELAYED COOLING ALOFT/LESS STEEP LAPSE RATES...INSTABILITY WILL BE
MARGINAL. MODEL LI/S ARE PROGGED ONLY AROUND ZERO. THEREFORE ANY
THUNDERSTORMS WOULD BE FEW AND FAR BETWEEN IF THEY WERE TO OCCUR AND
WILL NOT WORD IN ZONES. BEST CHANCES FOR PRECIPITATION WILL BE
TONIGHT AND SATURDAY FOR THE SIERRA/WESTERN NEVADA FROM RENO AND
TAHOE NORTHWARD WITH EMPHASIS SHIFTING SOUTH AND EAST WITH APPROACH
OF SECONDARY AND MORE SOUTHERN FEATURE OF AVN. MODEL QPF IS MARGINAL
AS FAR AS WINTER STORM LEVELS IN THE SIERRA ALTHOUGH OVERALL AMOUNTS
WILL LIKELY REACH A FOOT OR SO ONCE THE WEEKEND IS OVER. WILL HOLD
ON TO WATCH FOR THE NORTHERN SIERRA AS ONSET OF POTENTIALLY HEAVY
SNOW IS STILL SOME 14-18 HOURS AWAY. WHATEVER COURSE OF ACTION IS
TAKEN LATER TODAY...WARNING OR ADVISORY WOULD LIKELY NEED TO BE
EXPANDED INTO MONO COUNTY ALTHOUGH MORE IN LINE WITH A SATURDAY AND
SATURDAY NIGHT TIMING.

IN THE EXTENDED...MEDIUM RANGE MODEL CONFIDENCE IS VERY LOW. FOR
EXAMPLE AT APPROXIMATELY 45N/135W...THE 00Z TUESDAY NOGAPS 500MB
HEIGHT FIELD PORTRAYS A 576 HIGH WHILE THE UKMET HAS A 526 LOW
WILL STAY THE COURSE AND LEAVE EXTENDED ALONE TONIGHT. HOHMANN

.REV...WINTER STORM WATCH TNGT/SAT ABOVE 5500 FT CAZ071-072-NVZ002.