

107 

WWUS20 KWNS 212311

SEL8

SPC WW 212311

AZZ000-CAZ000-220500-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 8

NWS STORM PREDICTION CENTER NORMAN OK

405 PM MST THU JAN 21 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       A LARGE PART OF SOUTHWEST AND SOUTH CENTRAL ARIZONA

       SMALL PART OF SOUTHEAST CALIFORNIA



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 405 PM UNTIL

1000 PM MST.



TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 10 MILES NORTHWEST OF BLYTHE

CALIFORNIA TO 60 MILES SOUTH SOUTHEAST OF PHOENIX ARIZONA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 7...



DISCUSSION...A VERY STRONG/DEEP LOW PRESSURE MOVING INTO CA IS

ACCOMPANIED BY 180KT POLAR JET MAX CROSSING NRN BAJA THIS EVENING.

THIS PLACES AN UNUSUALLY POTENT WIND PROFILE ACROSS THE WATCH AREA

WHERE LOW LEVEL MOISTURE HAS SURGED NWD FROM THE GULF OF CA WITH

DEWPOINTS NOW INTO THE UPPER 50S LWR CO RIVER VALLEY.



A FORCED LINE ON LOW TOPPED THUNDERSTORMS IS DEVELOPING SERN CA AND

WILL CONTINUE EWD ACROSS THE WATCH THRU THE EVENING.  IN ADDITION TO

THE POTENTIAL FOR DAMAGING WINDS GIVEN THE INTENSITY OF THE LOW

LEVEL JET...ISOLATED TORNADOES WILL ALSO BE POSSIBLE EMBEDDED WITHIN

THE LINE AS LOW LEVEL SHEAR IS UPWARDS TO 50KTS AND LCL/S ARE

FAVORABLY LOW.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

350. MEAN STORM MOTION VECTOR 23050.





...HALES

