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260 

WWUS20 KWNS 281813

SEL9

SPC WW 281813

IAZ000-ILZ000-MOZ000-290000-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 109

NWS STORM PREDICTION CENTER NORMAN OK

115 PM CDT MON APR 28 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  SOUTH CENTRAL AND SOUTHEAST IOWA

  WEST CENTRAL ILLINOIS

  EAST CENTRAL AND NORTHEAST MISSOURI



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 115 PM UNTIL

  700 PM CDT.



* PRIMARY THREATS INCLUDE...

  A FEW TORNADOES POSSIBLE

  WIDESPREAD LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL

    EVENTS TO 2 INCHES IN DIAMETER POSSIBLE

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH OF OTTUMWA IOWA

TO 15 MILES SOUTHWEST OF SCOTT AFB ILLINOIS.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU9).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 108...



DISCUSSION...ARC OF LOW-TOPPED STORMS WILL CONTINUE TO DEVELOP FROM

ERN MO INTO SRN IA THROUGH THE AFTERNOON.  STEEP LAPSE RATES AND

STRONG SURFACE HEATING HAVE CONTRIBUTED TO MLCAPE OF 1000-1500 J/KG

AND SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS.  LARGE HAIL WILL BE

THE MAIN RISK...THOUGH A FEW TORNADOES WILL BE POSSIBLE AS STORMS

MOVE CLOSER TO THE STRONGER LOW-LEVEL SHEAR ZONE ALONG THE WARM

FRONT...AND WITH DEVELOPING UPDRAFTS IN IA ALONG THE BOUNDARY WHERE

VERTICAL VORTICITY IS STRONGEST.



AVIATION...TORNADOES AND 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 19030.





...THOMPSON

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