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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 691

NWS STORM PREDICTION CENTER NORMAN OK

1155 AM MST TUE OCT 5 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF SOUTHERN AND CENTRAL ARIZONA



EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1155 AM UNTIL 700

PM MST.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 90

STATUTE MILES EAST AND WEST OF A LINE FROM 70 MILES EAST

NORTHEAST OF PRESCOTT ARIZONA TO 100 MILES SOUTHWEST OF TUCSON

ARIZONA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



DISCUSSION...THUNDERSTORMS ARE INCREASING IN NUMBER AND INTENSITY

ACROSS SCENTRAL AZ WITH THE APPROACH OF S/WV TROUGH AND ASSOCIATED

MID LEVEL JET FROM SCAL.  WITH MLCAPES TO 1500 J/KG AND SHEAR FROM

35-40KT A FEW SEVERE THUNDERSTORMS INCLUDING THE POTENTIAL FOR

SUPERCELLS WILL DEVELOP N AND E ACROSS THE WATCH AREA THIS

AFTERNOON.  PRIMARY THREAT WILL BE LARGE HAIL AND BRIEF DAMAGING

WINDS.  ISOLATED TORNADO OR FUNNEL CLOUD WILL ALSO BE POSSIBLE

ASSOCIATED WITH ANY SUPERCELL THAT CAN DEVELOP.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 22030.





...HALES

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