

316 

WWUS20 KWNS 251936

SEL3

SPC WW 251936

IAZ000-ILZ000-MOZ000-260300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 373

NWS STORM PREDICTION CENTER NORMAN OK

235 PM CDT WED MAY 25 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       FAR SOUTHEAST IOWA

       CENTRAL AND NORTHERN ILLINOIS

       FAR NORTHEAST MISSOURI



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 235 PM UNTIL

1000 PM CDT.



TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 70 MILES NORTHEAST OF MOLINE

ILLINOIS TO 45 MILES WEST OF ALTON ILLINOIS.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU3).



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 368...WW 369...WW

370...WW 371...WW 372...



DISCUSSION...CLUSTER OF SEVERE STORMS --INCLUDING TORNADIC

SUPERCELLS-- OVER NERN MO WILL CONTINUE TO DEVELOP NEWD INTO AREA

THIS AFTERNOON IN ADVANCE OF DEEP-LAYER CYCLONE MOVING INTO NRN MO.

RELATIVELY CLOUD-FREE SKIES HAVE ALLOWED TEMPERATURES TO WARM

THROUGH THE 70S.  WHEN COUPLED WITH BOUNDARY LAYER DEWPOINTS IN THE

MID 60S AND COOLING MIDLEVEL TEMPERATURES ARE RESULTING IN A

MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE OF 1000-2000 J/KG.

GIVEN VERTICALLY VEERING WIND PROFILES AND AMBIENT VORTICITY INVOF

WARM FRONT...SETUP WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF

TORNADOES...LARGE HAIL AND DAMAGING WINDS.



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

SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 22035.





...MEAD

