WATCHES: Severe Thunderstorm Watch Number 426

WWUS20 KWNS 041910
SEL6
SPC WW 041910
ILZ000-INZ000-MIZ000-OHZ000-LEZ000-LMZ000-050200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 426
NWS STORM PREDICTION CENTER NORMAN OK
210 PM CDT SAT JUN 4 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

PARTS OF NORTHEAST ILLINOIS
MUCH OF NORTHERN INDIANA
PARTS OF SOUTHERN LOWER MICHIGAN
PARTS OF NORTHWEST OHIO
LAKE ERIE
LAKE MICHIGAN

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 210 PM UNTIL
900 PM CDT.

HAIL TO 2.5 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 70
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH
SOUTHWEST OF MARSEILLES ILLINOIS TO 35 MILES SOUTH SOUTHEAST OF
MOUNT CLEMENS MICHIGAN. FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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...WITH AIR MASS ACROSS THE WATCH VERY UNSTABLE WITH
MLCAPES AOA 3000J/KG AND LITTLE REMAINING CINH...THUNDERSTORMS
EXPECTED TO DEVELOP RAPIDLY REMAINDER OF AFTERNOON AND SPREAD
EASTWARD. WITH STEEP LAPSE RATES COUPLED WITH 30-40KT OF
SHEAR...LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THE
STRONGEST STORMS. INITIAL DEVELOPMENT WILL TAKE PLACE ON SUBTLE
SURFACE BOUNDARIES SUCH AS LAKE BREEZE FRONTS OF LM/LH.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM
MOTION VECTOR 27025.

...HALES

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.