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578 

WWUS20 KWNS 201704

SEL5

SPC WW 201704

TXZ000-210200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 195

NWS STORM PREDICTION CENTER NORMAN OK

1200 PM CDT THU MAY 20 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND NORTH TEXAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM NOON UNTIL 900

PM CDT.



TORNADOES...HAIL TO 4 INCHES IN DIAMETER...THUNDERSTORM WIND

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

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 20 MILES NORTHEAST OF TYLER

TEXAS TO 80 MILES WEST OF TEMPLE TEXAS.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 194...



DISCUSSION...TSTMS NOW NEAR COLD FRONT/OUTFLOW BOUNDARY INTERSECTION

IN NE TX EXPECTED TO DEVELOP SW ALONG COLD FRONT LATER TODAY AS SFC

HEATING FURTHER DESTABILIZES REGION REF MCD 633/.  LOW LVL FLOW WILL

REMAIN MODEST...WITH 850 MB SSW WINDS LIKELY TO REMAIN AROUND 20

KTS.  BUT WIND PROFILES WILL MAINTAIN DEEP-LAYER VEERING...WITH 250

MB WNW FLOW AROUND 70 KTS.  COUPLED WITH RICH LOW LVL MOISTURE AND

VERY STEEP LOW TO MID LVL LAPSE RATES...SETUP MAY SUPPORT A FEW

STRONG SUPERCELLS.  AS COLD FRONT IS QUITE SHALLOW AND SLOWLY

MOVING...THESE MAY REMAIN DISCRETE AND POSE A THREAT FOR

TORNADOES...IN ADDITION TO VERY LARGE HAIL AND LOCALLY DMGG WIND.



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

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

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

550. MEAN STORM MOTION VECTOR 28025.





...CORFIDI

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