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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 670

NWS STORM PREDICTION CENTER NORMAN OK

155 PM CDT TUE JUL 8 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL ILLINOIS

       NORTHERN AND PART OF CENTRAL MISSOURI



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 155 PM UNTIL

900 PM CDT.



HAIL TO 1.5 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTHWEST

OF KNOB NOSTER MISSOURI TO 25 MILES EAST OF SPRINGFIELD ILLINOIS.

 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 668...WW 669...



DISCUSSION...THUNDERSTORMS CONTINUE TO INCREASE ACROSS MO INTO

W-CENTRAL IL EARLY THIS AFTERNOON WITHIN AXIS OF MODERATE

INSTABILITY.  INITIAL DEVELOPMENT WILL LIKELY REMAIN WEAKLY

ORGANIZED OVER CENTRAL MO...WITH INCREASING SHEAR/ORGANIZATION INTO

MULTICELLS EXPECTED IN TIME TOWARDS NERN MO/IL.  DAMAGING WINDS AND

HEAVY RAINFALL WILL BE PRIMARY SEVERE THREATS WITH THE MORE INTENSE

CORES...ALONG WITH ISOLATED LARGE HAIL.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27020.





...EVANS

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