

000 

WWUS20 KWNS 212215

SEL4

SPC WW 212215

IAZ000-KSZ000-MOZ000-NEZ000-220500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 64

NWS STORM PREDICTION CENTER NORMAN OK

515 PM CDT WED MAR 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN IOWA

       NORTHEAST KANSAS

       NORTHWEST MISSOURI

       SOUTHEAST NEBRASKA



EFFECTIVE THIS WEDNESDAY AFTERNOON FROM 515 PM UNTIL MIDNIGHT CDT.



HAIL TO 2 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF

MASON CITY IOWA TO 25 MILES WEST OF MANHATTAN KANSAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU4).



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.



DISCUSSION...LINE OF THUNDERSTORMS IS INCREASING ALONG SURFACE COLD

FRONT OVER EASTERN NEB.  THESE STORMS ARE EXPECTED TO BECOME SEVERE

AND SPREAD EASTWARD INTO PARTS OF WESTERN IA AND NORTHWEST MO THIS

EVENING.  OTHER STORMS ARE EXPECTED TO DEVELOP SOUTHWARD ALONG FRONT

INTO PARTS OF NORTHEAST KS.  SUFFICIENT DEEP LAYER VERTICAL SHEAR

AND MODERATE INSTABILITY SUPPORT A RISK OF ORGANIZED MULTICELL OR

ISOLATED SUPERCELL STORMS CAPABLE OF LARGE HAIL AND DAMAGING WINDS.



AVIATION...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 450. MEAN STORM

MOTION VECTOR 26030.





...HART

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