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WWUS20 KWNS 180011

SEL5

SPC WW 180011

IAZ000-MNZ000-NEZ000-180700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 495

NWS STORM PREDICTION CENTER NORMAN OK

710 PM CDT FRI JUN 17 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN IOWA

       SOUTHWEST MINNESOTA

       EASTERN NEBRASKA



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 710 PM

UNTIL 200 AM 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 50

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES EAST

NORTHEAST OF BROOKINGS SOUTH DAKOTA TO 25 MILES WEST SOUTHWEST OF

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 492...WW 493...WW 494...



DISCUSSION...SCTD TSTMS EXPECTED TO CONTINUE FORMING ALONG SLOWLY

MOVING COLD FRONT NOW IN ERN NEB AND FAR ERN SD.  OTHER MORE ISOLD

STORMS MAY FORM ALONG N/S BOUNDARY AHEAD OF FRONT IN WRN IA.  DEEP

SHEAR AND LOW LVL WIND FIELD SHOULD REMAIN FAIRLY WEAK.  BUT

GLANCING INFLUENCE OF WRN ND SHORTWAVE IMPULSE AND DEGREE OF

INSTABILITY /PER 00Z OAX SOUNDING/ SUGGEST THAT AT LEAST THAT SOME

STORMS IN NARROW CORRIDOR OF WW AREA WILL HAVE A CHANCE FOR LARGE

HAIL...DMGG WIND...AND PERHAPS A TORNADO THROUGH LATE EVE.



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 23025.





...CORFIDI

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