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WWUS20 KWNS 080030

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SPC WW 080030

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 170

NWS STORM PREDICTION CENTER NORMAN OK

730 PM CDT MON APR 7 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN OKLAHOMA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 730 PM UNTIL

300 AM CDT.



HAIL TO 2.5 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 45

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

CLINTON OKLAHOMA TO 65 MILES EAST NORTHEAST OF TULSA OKLAHOMA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 169...



DISCUSSION...SEVERE THUNDERSTORMS...INCLUDING SUPERCELLS...WILL

CONTINUE INCREASING IN COVERAGE ACROSS NRN AND NERN OK TONIGHT.

THIS WILL OCCUR AS SSWLY LLJ INTENSIFIES AND FUELS STRONG LOW LEVEL

WAA ALONG AND NORTH OF SURFACE FRONT NOW EXTENDING FROM NERN INTO

W-CENTRAL OK.  STRONG SHEAR AND STEEP LAPSE RATES WILL COMPENSATE

FOR MODEST MUCAPE AND SUPPORT STORMS CAPABLE OF LARGE HAIL...SOME OF

WHICH COULD BE QUITE LARGE...AS ACTIVITY EVOLVES INTO A LARGER

CLUSTER/MCS AFTER DARK.  ISOLATED DAMAGING WINDS AND EVEN A BRIEF

TORNADO WILL ALSO BE POSSIBLE WITH STORMS NEAR THE SURFACE FRONT

INTO THE MID/LATE EVENING.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 24035.





...EVANS

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