

780 

WWUS20 KWNS 241840

SEL9

SPC WW 241840

ILZ000-MOZ000-250200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 359

NWS STORM PREDICTION CENTER NORMAN OK

140 PM CDT TUE MAY 24 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN ILLINOIS

       NORTHERN AND EASTERN MISSOURI



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 140 PM UNTIL

900 PM 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTH OF

KNOB NOSTER MISSOURI TO 35 MILES NORTH OF SAINT LOUIS MISSOURI.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 354...WW 355...WW

356...WW 357...WW 358...



DISCUSSION...BOWING MCS OVER NWRN MO IS EXPECTED TO BECOME

PROGRESSIVELY SURFACE-BASED THIS AFTERNOON AS DOWNSTREAM AIR MASS

WARMS THROUGH THE 80S...CONTRIBUTING TO MLCAPE VALUES OF 1500-2500

J/KG.  CURRENT EAX VAD SHOWS 50+ KT WSWLY WINDS ABOVE 5-6 KM AGL

WHICH WILL RESULT IN MODERATELY STRONG DEEP-LAYER SHEAR AND THE

POTENTIAL FOR FORWARD-PROPAGATION OF MCS.  A CORRIDOR OF DAMAGING

WINDS WILL BE POSSIBLE ALONG SYSTEM TRACK AS WELL AS LARGE HAIL.



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 500. MEAN STORM

MOTION VECTOR 29035.





...MEAD

