999 
FXUS65 KVEF 142351
AFDLAS

MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
350 PM PST SUN MAR 14 1999

SYNOPSIS...A PACIFIC LOW PRESSURE SYSTEM AND ITS ASSOCIATED COLD
FRONT WILL SLOWLY MOVE DOWN THE WEST COAST TONIGHT AND ACROSS
SOUTHERN CALIFORNIA MONDAY. COOL AND UNSETTLED WEATHER WILL ACCOMPANY
THIS SYSTEM THROUGH TUESDAY AS IT GRADUALLY EXITS TO THE EAST.

DISCUSSION...ELONGATED TROUGH OFF WEST COAST SLOWLY MOVING EAST WITH
AXIS CURRENTLY CENTERED ALONG 127W AND MAIN CIRCULATION NEAR 33N.
HIGH LEVEL MOISTURE HAS SPREAD ACROSS WESTERN STATES WHILE LOW LEVEL
MOISTURE REMAINS MAINLY OVER NORTHERN CALIFORNIA WITH NORTH/SOUTH
ORIENTED BAROCLINIC BAND.  SATELLITE IMAGERY INDICATES THE TROUGH IS
STILL DIGGING AS IT PROGRESSES EAST. PREFERRED 12Z AVN SOLUTION WITH
SLOWER MOVEMENT.  APPEARS CENTER WILL MOVE INTO SOUTHERN CALIFORNIA
BY 00Z TUESDAY.  EXPECT ONSET OF PRECIPITATION FOR SOUTHERN SIERRA
LATE TONIGHT BUT BELIEVE BEST AMOUNTS WILL FALL MONDAY AS FLOW TURNS
MORE SOUTH TO SOUTHEAST.  ALSO...LOOKS LIKE SNOW LEVELS WILL STAY UP
ABOVE OWENS VALLEY FLOOR AS COLDER AIR SLIDES SOUTH.  THEREFORE...
DECIDED AGAINST SNOW ADVISORY.  MOISTURE AND COLD AIR WORK INTO
SOUTHERN PART OF FORECAST AREA LATE MONDAY AND LINGER THROUGH TUESDAY
AND WILL MENTION SCATTERED SHOWERS MOST ZONES ALONG WITH
THUNDERSTORMS DUE TO INCREASED INSTABILITY. 

FOR EXTENDED PERIOD...ATMOSPHERE GRADUALLY DRIES TUESDAY NIGHT AND
STAYS THAT WAY THROUGH FRIDAY AS SHORTWAVE RIDGE MOVES OVER.  ECMWF
AND MRF INDICATE SHORTWAVE MOVING INTO NORTHERN GREAT BASIN LATE IN
THE PERIOD BUT ECMWF SLOWER AND SLIGHTLY DEEPER THAN MRF.  MENTIONED
CHANCE OF SHOWERS FOR NORTHWEST PART OF FORECAST AREA FRIDAY.  JGA

.LAS...NONE.