

727 

WWUS20 KWNS 100405

SEL9

SPC WW 100405

IAZ000-MNZ000-WIZ000-101000-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 119

NWS STORM PREDICTION CENTER NORMAN OK

1100 PM CDT SAT APR 9 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHERN IOWA

       FAR SOUTHEAST MINNESOTA

       SOUTHWEST WISCONSIN



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1100 PM

UNTIL 500 AM CDT.



TORNADOES...HAIL TO 1.5 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 40 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 40 MILES WEST SOUTHWEST OF

SPENCER IOWA TO 50 MILES EAST SOUTHEAST OF LA CROSSE WISCONSIN.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 116...WW 117...WW 118...



DISCUSSION...LONG-LIVED SUPERCELLS THAT FORMED EARLIER THIS EVE IN

NW IA HAVE EVOLVED INTO SEVERAL COMPLEX CLUSTERS THAT ARE EXPECTED

TO CONTINUE MOVING ENE ALONG SLOWLY-ADVANCING WSW-ENE WARM FRONT NOW

OVER NRN IA.  KDSM VWP SHOWS A 70 KT 3-4 KM DEEP SLY LLJ AIMED INTO

FRONTAL ZONE.  COUPLED WITH WEAKER SELY NEAR-SFC FLOW OVER ERN

IA...AMPLE LOW LVL SHEAR APPEARS TO EXIST TO SUPPORT MAINTENANCE OF

EXISTING LOW-LVL MESO CYCLONES AND ASSOCIATED TORNADO THREAT INTO

RECOVERING BOUNDARY LAYER ENVIRONMENT OVER FAR NE IA...SE MN...AND

SW WI.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 26035.





...CORFIDI

