

552 

WWUS20 KWNS 072205

SEL8

SPC WW 072205

ARZ000-ILZ000-MOZ000-080500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 608

NWS STORM PREDICTION CENTER NORMAN OK

505 PM CDT THU JUL 7 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN ARKANSAS

       SOUTHWEST ILLINOIS

       EASTERN AND SOUTHERN MISSOURI



EFFECTIVE THIS THURSDAY AFTERNOON FROM 505 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES WEST

NORTHWEST OF SPRINGFIELD MISSOURI TO 25 MILES EAST NORTHEAST OF

CAPE GIRARDEAU MISSOURI.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...TSTMS ARE INTENSIFYING ALONG ENE-WSW ORIENTED

BAROCLINIC ZONE FROM N OF TBN TO VICINITY OF STL...AS WELL AS ALONG

MORE N-S ORIENTED WARM FRONT NE OF HRO.  AMBIENT WARM SECTOR AIR

MASS IS QUITE MOIST WITH DEWPOINTS IN THE LOW/MID 70S WHICH IS

LARGELY CONTRIBUTING TO MLCAPE OF 1500-3500 J/KG.  WHEN COUPLED WITH

A KINEMATIC ENVIRONMENT FEATURING PRONOUNCED VEERING OF WINDS WITH

HEIGHT AND 30-40 KT OF DEEP NWLY SHEAR...SETUP WILL FAVOR THE

DEVELOPMENT OF SUPERCELLS AND ORGANIZED MULTICELL STRUCTURES.  WHILE

A TORNADO IS POSSIBLE...LARGE HAIL AND DAMAGING WINDS APPEAR TO BE

THE PRIMARY HAZARDS.



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 550. MEAN STORM

MOTION VECTOR 30025.





...MEAD

