

000 

WWUS20 KWNS 212213

SEL9

SPC WW 212213

IAZ000-ILZ000-MOZ000-NEZ000-220500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 719

NWS STORM PREDICTION CENTER NORMAN OK

510 PM CDT MON JUL 21 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHERN IOWA

       WEST CENTRAL ILLINOIS

       NORTHERN MISSOURI

       FAR SOUTHEASTERN NEBRASKA



EFFECTIVE THIS MONDAY AFTERNOON FROM 510 PM UNTIL MIDNIGHT CDT.



HAIL TO 3 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHWEST

OF SHENANDOAH IOWA TO 65 MILES EAST SOUTHEAST OF BURLINGTON IOWA.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 717...WW 718...



DISCUSSION...COMPLEX SCENARIO EXPECTED TO UNFOLD THIS EVENING ACROSS

WW...AS SEVERE THUNDERSTORMS BECOME INCREASINGLY WIDESPREAD.

ACTIVITY SHOULD INTENSIFY IN SSEWD MOVING BAND OVER SRN IA AHEAD OF

STRONG MID/UPPER TROUGH...WITH ADDITIONAL DEVELOPMENT EXPECTED INVOF

SURFACE FRONT FROM FAR SERN NEB INTO NWRN IL WHERE CAPPING HAS

ERODED.  AIR MASS IS EXTREMELY UNSTABLE ACROSS MUCH OF THE

WW...SUGGESTING STORMS WILL RAPIDLY BECOME SEVERE.  SUPERCELLS AND

SMALL LINES/BOW ECHOES ARE LIKELY... WITH POTENTIAL FOR MORE

ORGANIZED BOWING LINE BY THE MID TO LATE EVENING.  VERY LARGE HAIL

AND POSSIBLY WIDESPREAD DAMAGING WINDS CAN BE EXPECTED.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 32025.





...EVANS

