

483 

WWUS20 KWNS 221754

SEL3

SPC WW 221754

IAZ000-ILZ000-KSZ000-MOZ000-230200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 323

NWS STORM PREDICTION CENTER NORMAN OK

1255 PM CDT SUN MAY 22 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       EASTERN IOWA

       WESTERN ILLINOIS

       EAST-CENTRAL KANSAS

       NORTHERN MISSOURI



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL

900 PM CDT.



TORNADOES...HAIL TO 3 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 90 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH NORTHWEST OF

DUBUQUE IOWA TO 25 MILES WEST SOUTHWEST OF COLUMBIA MISSOURI.

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 321...WW 322...



DISCUSSION...TSTMS ARE IN THE PROCESS OF DEVELOPING ALONG PRIMARY

COLD FRONT EXTENDING FROM N-CNTRL IA TO E-CNTRL KS AS WELL AS ALONG

GRAVITY WAVE-INDUCED SURFACE CONVERGENCE BOUNDARY FROM CNTRL IL INTO

E-CNTRL MO.  AMBIENT WARM SECTOR AIR MASS IS QUITE MOIST AND

MODERATELY TO STRONGLY UNSTABLE WITH MLCAPE VALUES OF 2000-3500

J/KG.  WHEN COUPLED WITH 40-50 KT OF DEEP-LAYER SHEAR AND MODERATELY

STRONG LOW-LEVEL SHEAR...THE POTENTIAL WILL EXIST FOR SUPERCELLS

CAPABLE OF DESTRUCTIVE HAIL AND TORNADOES...SOME POSSIBLY STRONG.



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

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

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

600. MEAN STORM MOTION VECTOR 24030.





...MEAD

