Severe Thunderstorm Warning 11, NWS Sacramento, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
310 PM PDT TUE APR 29 2003

CONVECTIVELY ACTIVE AFTERNOON OVER NORCAL WITH UPPER LOW JUST NOW
SPINNING INLAND NEAR THE CA/OR BORDER. COOL POOL DYNAMICS WERE
MODELED QUITE NICELY WITH CONVECTIVE ELEMENTS MAINLY AFFECTING AREAS
FROM AROUND I-80 NORTHWARD THIS AFTERNOON. SURFACE FLOW HAS BECOME
MORE SOUTHWESTERLY SOUTH OF I-80 RESULTING IN A LESS FAVORABLE SHEAR
PROFILE FOR ORGANIZED CONVECTION.

AS UPPER LOW WEAKENS OVERNIGHT...SHOWER COVERAGE IS EXPECTED TO
BEGIN TO DIMINISH FROM SOUTH TO NORTH. WITH WEAK SHORT WAVE RIDGING
DEVELOPING ON WEDNESDAY...WOULD EXPECT ONLY LINGERING SHOWERS TO BE
CONFINED TO OUR NORTHERN MOUNTAINS. SHORT WAVE RIDGE SHOULD PROVIDE
DRY CONDITIONS WEDNESDAY NIGHT INTO THURSDAY.

NEXT SYSTEM MODELED TO DROP OUT OF THE GULF OF ALASKA AND SLIDE
SOUTHWARD AROUND 140W THROUGH WEDNESDAY NIGHT. SAID LOW BEGINS
EJECTING EAST AROUND 35N...THEN TAKES AIM ON CENTRAL/NORTHERN CA
WITH COLD FRONT REACHING OUR AREA FRIDAY. COULD BE ANOTHER FAIRLY
SIGNIFICANT PRECIP PRODUCER SHOULD THE MODELS VERIFY WITH THE
POTENTIAL FOR ANOTHER 1 TO 1.5 INCHES OF PRECIP IN THE CENTRAL
SIERRA.

UPPER TROUGH SWINGS THROUGH NORCAL ON SATURDAY WITH TRACK OF UPPER
LOW QUITE SUPPORTIVE FOR ISOLATED THUNDERSTORMS AT LEAST OVER THE
SOUTHERN HALF OF OUR FORECAST AREA. TROUGH FINALLY SWINGS EAST OF
OUR AREA BY SUNDAY WITH A SHIFT TO DRIER NORTHWEST FLOW ALOFT. COULD
BE THE START OF A DECENT STRETCH OF SPRING-LIKE WEATHER WITH MORE
PRONOUNCED RIDGING INDICATED FOR EARLY NEXT WEEK BRINGING A WARMING
AND DRYING TREND.

.STO...NONE.

BLU BE 030/045 034/051 036 66620
RBL BB 046/065 048/072 050 66610
SAC BB 045/067 047/070 049 66300

JJ

CAZ013>019-063-064-066>069-301400-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SACRAMENTO CA
700 AM PDT TUE APR 29 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR INTERIOR NORTHERN CALIFORNIA.

.DAY ONE...TODAY

UPPER LEVEL LOW PRESSURE SYSTEM CENTERED ALONG THE NORTH COAST OF
CALIFORNIA WILL SLOWLY MOVE INLAND TODAY BRINGING PERIODS OF SHOWERS
AND ISOLATED THUNDERSTORMS TO THE INTERIOR OF NORTHERN CALIFORNIA. A
SNOW ADVISORY HAS BEEN ISSUED FOR THE INTERIOR COASTAL RANGE NORTH
OF LAKE COUNTY AND FOR THE MOUNTAINS OF SHASTA COUNTY INCLUDING THE
BURNEY BASIN AREA AND THE WEST SLOPES OF THE NORTHERN SIERRA
NEVADA...WESTERN PLUMAS COUNTY AND LASSEN PARK FOR TODAY. (SEE
WWUS46 KSTO - WSWSTO FOR DETAILS).

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A LOW PRESSURE SYSTEM WILL MOVE THROUGH CENTRAL CALIFORNIA ON FRIDAY
AND SATURDAY (DAYS 4 AND 5) BRINGING SNOW TO THE HIGHER
ELEVATIONS...OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THEIR LOCAL NATIONAL WEATHER SERVICE.

THE LATEST WEATHER INFORMATION IS AVAILABLE ON THE INTERNET
AT (LOWER CASE): HTTP://WWW.WRH.NOAA.GOV/SACRAMENTO

SMITH