URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 842
STORM PREDICTION CENTER NORMAN OK
1253 PM PST SUN DEC 2 2001

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

NORTHERN CALIFORNIA

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 100 PM UNTIL 600
PM PST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO
60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 45 STATUTE MILES EITHER SIDE OF
A LINE FROM 50 MILES NORTH OF RED BLUFF CALIFORNIA TO 35 MILES EAST
SOUTHEAST OF SACRAMENTO CALIFORNIA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

DISCUSSION...DAYTIME HEATING/ARRIVAL OF COLDER AIR ALOFT HAVE
RESULTED IN SUFFICIENT DESTABILIZATION TO PRODUCE SCATTERED DEEP
CONVECTION OVER THE COASTAL RANGES AND PARTS OF THE SACRAMENTO
VALLEY IN THE LAST 1-2 HOURS. STRENGTHENING TREND SHOULD CONTINUE
FOR THE NEXT SEVERAL HOURS...WITH A THREAT FOR SUPERCELLS/TORNADOES
GIVEN BACKED NEAR-SURFACE FLOW BENEATH 50+ KT SW JET AT 700 MB.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH...EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 300.
MEAN STORM MOTION VECTOR 24035.

...CORFIDI