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WWUS20 KWNS 291100

SEL5

SPC WW 291100

OKZ000-TXZ000-291800-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 5

NWS STORM PREDICTION CENTER NORMAN OK

500 AM CST TUE JAN 29 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN AND CENTRAL OKLAHOMA

       FAR NORTHWEST TEXAS



EFFECTIVE THIS TUESDAY MORNING FROM 500 AM UNTIL NOON CST.



TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS

TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTHWEST OF FORT

SILL OKLAHOMA TO 20 MILES NORTH NORTHWEST OF PONCA CITY OKLAHOMA.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



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...TSTMS HAVE RECENTLY INTENSIFIED ALONG THE DRYLINE OVER

WRN OK IN RESPONSE TO INCREASING HEIGHT FALLS ASSOCIATED WITH WRN

U.S. TROUGH.  THESE STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY THIS MORNING AS LARGE-SCALE FORCING FOR ASCENT FURTHER

STRENGTHENS...AND AS LOW-LEVEL CONVERGENCE IS ENHANCED BY A

MIGRATORY SURFACE LOW DEVELOPING NEWD ACROSS THE WATCH AREA.

MODEL-DERIVED FORECAST SOUNDINGS INDICATE THAT BOUNDARY LAYER

DEWPOINTS IN THE LOWER 60S ARE CONTRIBUTING TO MLCAPE VALUES OF

500-1000 J/KG WITH LITTLE OR NO CONVECTIVE INHIBITION.  WHEN COUPLED

WITH 60 KT OF EFFECTIVE BULK SHEAR AND EFFECTIVE SRH VALUES OF

300-350 M2/S2...THE ENVIRONMENT WILL SUPPORT SUPERCELLS AND BOWING

LINE SEGMENTS CAPABLE OF DAMAGING WINDS AND A FEW TORNADOES.



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

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400.

MEAN STORM MOTION VECTOR 23045.





...MEAD

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