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WWUS20 KWNS 191913

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SPC WW 191913

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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 190

NWS STORM PREDICTION CENTER NORMAN OK

205 PM CDT WED MAY 19 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       MUCH OF OKLAHOMA



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 205 PM UNTIL

1000 PM CDT.



...THIS IS A PARTICULARLY DANGEROUS SITUATION...



DESTRUCTIVE TORNADOES...LARGE HAIL TO 3.5 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 55 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH OF GAGE

OKLAHOMA TO 40 MILES EAST SOUTHEAST OF MCALESTER OKLAHOMA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU0).



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 EXPECTED TO FORM IN THE NEXT HOUR OR SO INVOF

SLOWLY RETREATING W/E OUTFLOW BOUNDARY IN W CNTRL OK.  OTHER STORMS

ALSO MAY FORM A BIT LATER NEAR INTERSECTION OF OUTFLOW BOUNDARY WITH

CONFLUENCE LINE IN CNTRL OK...AND IN MORE STRONGLY HEATED

ENVIRONMENT NEAR WARM FRONT IN SE OK /REF MCD 623/.

GIVEN STRENGTH OF WIND FIELD...EXPECTATION OF CONTINUED LOW LVL

DESTABILIZATION...AND EVENTUAL ONSET OF MID LVL COOLING/ASCENT WITH

UPR IMPULSE NOW IN THE WRN TX PANHANDLE...SETUP APPEARS FAVORABLE

FOR THE DEVELOPMENT OF STRONG SUPERCELLS.  ONE OR TWO OF THESE MAY

BECOME LONG-LIVED...AND YIELD A COUPLE STRONG TORNADOES...AS THEY

INTERACT WITH BACKED LOW LVL FLOW NEAR OUTFLOW BOUNDARY AND/OR WARM

FRONT.



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

SURFACE AND ALOFT TO 3.5 INCHES. EXTREME TURBULENCE AND SURFACE

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

550. MEAN STORM MOTION VECTOR 26030.





...CORFIDI

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