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000 

WWUS20 KWNS 311847

SEL1

SPC WW 311847

IAZ000-ILZ000-MOZ000-010200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 101

NWS STORM PREDICTION CENTER NORMAN OK

145 PM CDT SAT MAR 31 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EASTERN IOWA

       PARTS OF WESTERN ILLINOIS

       PARTS OF NORTHEAST MISSOURI



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 145 PM UNTIL

900 PM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE

MILES EAST AND WEST OF A LINE FROM 60 MILES EAST NORTHEAST OF

MASON CITY IOWA TO 30 MILES SOUTHWEST OF QUINCY ILLINOIS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU1).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 99...WW 100...



DISCUSSION...AIR MASS CONTINUES TO DESTABILIZE AHEAD OF VIGOROUS

TROUGH AND 90KT MID LEVEL WIND MAX.  WITH MLCAPES TO NEAR 1000 J/KG

SUFFICIENT CAPE/SHEAR TO SUPPORT SUPERCELLS.  WARM FRONT SHIFTING

NWD ACROSS ERN IA WILL ALSO ENHANCE LOW LEVEL SHEAR AND TORNADO

POTENTIAL. THUNDERSTORMS NOW DEVELOPING ACROSS NRN MO/IA WILL

RAPIDLY INTENSIFY AND BECOME MORE WIDESPREAD THRU THE AFTERNOON.



AVIATION...TORNADOES AND 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 22040.





...HALES

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