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443 

WWUS20 KWNS 061957

SEL7

SPC WW 061957

IAZ000-070300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 57

NWS STORM PREDICTION CENTER NORMAN OK

300 PM CDT TUE APR 6 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN IOWA



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 300 PM UNTIL

1000 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 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 45 MILES EAST OF LAMONI IOWA

TO 45 MILES NORTH OF CEDAR RAPIDS IOWA.  FOR A COMPLETE DEPICTION

OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS

WOU7).



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 56...



DISCUSSION...THUNDERSTORMS ARE EXPECTED TO DEVELOP RAPIDLY THIS

AFTERNOON IN WARM SECTOR OF LOW NEAR DSM.  THESE STORMS WILL TRACK

NORTHEASTWARD THROUGH THE AFTERNOON AND EVENING INTO NORTHEAST IA.

SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS ARE EXPECTED.

FAVORABLE LOW LEVEL AND DEEP LAYER VERTICAL SHEAR...ESPECIALLY IN

VICINITY OF THE SURFACE WARM FRONT...WILL PROMOTE THE POTENTIAL FOR

A FEW TORNADOES.



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

500. MEAN STORM MOTION VECTOR 25035.





...HART

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