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000 

WWUS20 KWNS 211528

SEL3

SPC WW 211528

IAZ000-MOZ000-212300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 63

NWS STORM PREDICTION CENTER NORMAN OK

1025 AM CDT WED MAR 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN IOWA

       NORTHERN MISSOURI



EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 1025 AM UNTIL

600 PM CDT.



HAIL TO 2 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 EAST AND WEST OF A LINE FROM 45 MILES NORTHWEST OF

CEDAR RAPIDS IOWA TO 50 MILES SOUTHEAST OF CHILLICOTHE MISSOURI.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



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.



DISCUSSION...ELEVATED STORMS FROM CENTRAL IA INTO NWRN MO ARE

ASSOCIATED WITH A MID LEVEL SHORT WAVE TROUGH MOVING ACROSS THE

LOWER MISSOURI VALLEY.  12Z OBSERVED AND RUC ANALYSIS SOUNDINGS

INDICATE ACTIVITY IS CURRENTLY ROOTED ABOVE THE SURFACE WITHIN

ENVIRONMENT CHARACTERIZED BY STEEP MID LEVEL LAPSE RATES AND MUCAPE

UP TO 1500 J/KG.  VISIBLE IMAGERY SUGGESTS ENHANCED HEATING WILL

TAKE PLACE ACROSS NRN MO INTO SERN IA WITH INCREASING POTENTIAL FOR

STORMS TO BECOME SURFACE-BASED THIS AFTERNOON WITH ATTENDANT THREAT

FOR CONTINUED HAIL AND STRONG WIND GUSTS.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 24025.





...WEISS

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