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701 

WWUS20 KWNS 210004

SEL6

SPC WW 210004

IAZ000-MNZ000-NEZ000-SDZ000-210700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 526

NWS STORM PREDICTION CENTER NORMAN OK

655 PM CDT MON JUN 20 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN AND CENTRAL IOWA

       SOUTHWEST MINNESOTA

       EASTERN AND NORTHERN NEBRASKA

       SOUTHEAST SOUTH DAKOTA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 655 PM UNTIL

200 AM CDT.



TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 105 STATUTE

MILES EAST AND WEST OF A LINE FROM 15 MILES SOUTHEAST OF

SHENANDOAH IOWA TO 35 MILES NORTHEAST OF MITCHELL SOUTH DAKOTA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 523...WW 524...WW 525...



DISCUSSION...ARC OF SUPERCELLS EXTENDING FROM NEAR ONL TO W OF OLU

TO W OF BIE EXPECTED TO ACCELERATE NNE/NE LATER THIS EVE AS

WRN/CNTRL KS VORT LOBE ASSUMES A MORE NEGATIVE TILT.  OTHER STORMS

MAY CONTINUE TO FORM ALONG N/S INVERTED TROUGH IN SE SD.  IN

ADDITION...WDLY SCTD STORMS MAY FORM LATER THIS EVE NEAR WEAK WARM

FRONT IN WRN/CNTRL IA.  THE MAIN ARC OF STORMS SHOULD EVOLVE INTO A

BROKEN SQLN/QLCS WITH TIME...BUT STRENGTH OF SHEAR AND DEGREE OF

INSTABILITY SUGGEST A CONTINUED POTENTIAL FOR ISOLD TORNADOES IN

ADDITION TO LARGE HAIL/HIGH WIND FROM EMBEDDED SUPERCELLS.

TORNADOES ALSO CANNOT BE RULED OUT WITH ACTIVITY ALONG INVERTED

TROUGH...AND WITH ANY STORMS THAT FORM AHEAD OF SQLN IN IA.



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

SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 21035.





...CORFIDI

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