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WWUS20 KWNS 222009

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IAZ000-NEZ000-230300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 430

NWS STORM PREDICTION CENTER NORMAN OK

310 PM CDT MON JUL 22 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHWEST IOWA

  EASTERN NEBRASKA



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 310 PM UNTIL

  1000 PM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 75

    MPH POSSIBLE

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES SOUTHEAST

OF MASON CITY IOWA TO 30 MILES WEST OF TEKAMAH NEBRASKA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 429...



DISCUSSION...STORMS SHOULD INCREASE ALONG A COLD FRONT SETTLING

ACROSS THE REGION THOUGH THE REMAINDER OF THE AFTERNOON. A VERY HOT

AND UNSTABLE AIRMASS HAS DEVELOPED ALONG THE FRONTAL ZONE WITH

MLCAPE AROUND 3000 J/KG INDICATED IN LATEST ENVIRONMENT DATA. THIS

IN COMBINATION WITH CONTINUED LOW LEVEL LIFT ALONG THE FRONTAL

SEGMENT SHOULD SPUR ADDITIONAL INTENSE TSTM DEVELOPMENT. DEEP SHEAR

ACROSS THE REGION IS LIMITED AND MAY RESULT IN GENERALLY POOR STORM

ORGANIZATION WITH MULTICELL/PULSE CONVECTION POSING PRIMARILY A WIND

DAMAGE THREAT INTO THE EARLY EVENING.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 29020.





...CARBIN

