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000 

WWUS20 KWNS 221850

SEL2

SPC WW 221850

IAZ000-MOZ000-230200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 442

NWS STORM PREDICTION CENTER NORMAN OK

150 PM CDT FRI JUN 22 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       IOWA

       FAR NORTHEASTERN MISSOURI



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 150 PM UNTIL 900

PM 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 90

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES EAST

NORTHEAST OF FORT DODGE IOWA TO 55 MILES SOUTH SOUTHWEST OF

OTTUMWA IOWA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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...STORMS ALREADY INCREASING ACROSS CENTRAL IA INVOF SLOW

MOVING MCV AND NEAR SURFACE OUTFLOW BOUNDARY.  AIR MASS IS QUITE

UNSTABLE...AND WILL DESTABILIZE FURTHER INTO ERN IA GIVEN MODERATE

TO STRONG HEATING.  SHEAR ACROSS MUCH OF CENTRAL IA REMAINS

SUFFICIENT FOR SUPERCELLS NEAR A 40 KT WLY MID SPEED MAX ASSOCIATED

WITH SLOW MOVING MCV.  ACTIVITY WILL LIKELY CONSOLIDATE LATER TODAY

INTO A MCS.  LARGE HAIL AND ISOLATED DAMAGING WINDS SHOULD OCCUR

WITH THESE STORMS.



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 27015.





...EVANS

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