Flooding in California, April 21, 2001

EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION...AMD
NATIONAL WEATHER SERVICE SAN DIEGO CA
800 PM PDT FRI APR 20 2001

                             ...SYNOPSIS...
A COLD UPPER LEVEL LOW PRESSURE SYSTEM WILL DROP INTO SOUTHERN
CALIFORNIA LATE TONIGHT AND SATURDAY WITH RAIN AND SOME SNOW IN THE
MOUNTAINS. IT WILL ALSO BE WINDY IN THE MOUNTAINS AND DESERTS AND
LOCALLY BREEZY ELSEWHERE. THE STORM WILL MOVE OUT RAPIDLY SATURDAY
NIGHT. HIGH PRESSURE ALOFT WILL INCREASE OVER THE AREA SUNDAY
THROUGH TUESDAY. THE HIGH WILL WEAKEN AFTER THE MIDDLE OF NEXT WEEK.

                            ...DISCUSSION...
AMENDED TIMES FOR ARRIVAL AS FNT HAS INCREASED SPEED. LOW CLDS
GETTING THICKER TO THE NORTH WITH -RA OVR VENTURA AND LA COUNTIES.
XPC LOW CLDS TO THICKEN TNGT OVR THE AREA WITH -RA SCT ABOUT. FNT
MOVING DOWN THE CST AND MOVING PAST MONTEREY BAY AT 01Z WITH THE UPR
LVL LOW OFF THE NORCAL CST. FNT ESTIMATED TO MOVE INTO NORTHERN
ORANGE CO AT 0800Z AND NORTHERN SAN DIEGO CO AT 0900Z AND HIT
LINDBERGH FIELD AT 1000Z AS TOLD BY AWIPS TOOLS. MODELS MAKE IT LOOK
RATHER IMPRESSIVE FOR THIS TIME OF THE YEAR. POPS MAY BE TOO LOW AND
IF RAIN DEVELOPS AS IT IS TO THE NORTH THEN WILL MAKE IT
CATEGORICAL. STRONG BULLSEYE OF UVV DOWN TO CENTRAL CA LATE TNGT BUT
MOVES THRU FAST AND DVV MOVES IN SAT AFTN. AMOUNTS LOOK LIKE 1/4-1/2
INCH IN THE CSTL TO VALLEYS AND 1/2 TO ONE INCH IN THE MTNS WITH A
FEW INCHES OF SNOW. SFC GRADS AND UPR LVL WINDS WILL MAKE IT WINDY
IN THE MTNS AND DSRTS AND BREEZY ELSW ON SAT. SYS SHUD BLOW OUT OF
THE AREA FAST LIKE SAT NGT OR SOONER. SHUD BE CLR AND QUITE COLD SAT
NGT. IT WILL BE A LOT WARMER RAPIDLY AS 50H HI INCREASES SUN THRU
TUE. WEAK OFSHR POSSIBLE MON AND TUE MORNS TO HELP JACK UP THE AFTN
HIGH TEMPS. NO UPDATE ATTM.

SAN 4700

.SAN...WINTER WEATHER ADVISORY...SEE LAXWSWSAN.

WHITLOW