Warning Description: Severe Thunderstorm Watch

Warning Date: 9:15 PM CDT on July 21, 2008

WarningSum:


Warning Message:The NWS Storm Prediction Center has issued a
Severe Thunderstorm Watch for portions of 
       southern Illinois
       southwest Indiana
       central and eastern Missouri
Effective this Monday night and Tuesday morning from 915 PM until
300 am 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 50
statute miles north and south of a line from 25 miles west of
Columbia Missouri to 50 miles northeast of Evansville Indiana. 
For a complete depiction of the watch see the associated watch
outline update (wous64 kwns wou1).
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 719...ww 720...
Discussion...linear MCS will continue to sag ssewd across this
region tonight and feed of a very unstable air mass in place
represented by MLCAPE in excess of 4000 j/kg at mid evening. 
Combined with 30-40 kt deep layer shear...this will prove more than
adequate for threats of large hail and damaging winds.  Organization
into one or more bowing mcss also remains possible late this
evening.
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 550. Mean storm
motion vector 34025.
...Evans