[LeArc] Weather Watch : 8@ 4/20/2003 12:19:03 PM

[learc@mailman.qth.net]

The following weather message is provided by McDonough County E.S.D.A.


WWUS20 KWNS 201718
SEL8  
SPC WW 201720
ILZ000-INZ000-202300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 138
STORM PREDICTION CENTER NORMAN OK
1220 PM EST SUN APR 20 2003

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

EASTERN ILLINOIS                           
INDIANA                            

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1220 PM UNTIL 600
PM EST.

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 ALONG AND 75 STATUTE MILES
EAST AND WEST OF A LINE FROM 10 MILES SOUTHEAST OF EVANSVILLE
INDIANA TO 55 MILES NORTH NORTHWEST OF FORT WAYNE INDIANA.

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...THUNDERSTORMS ARE DEVELOPING IN SEVERAL WARM SECTOR
BANDS ACROSS ERN IL/WRN INDIANA...TO THE E OF THE COLD FRONT IN IL. 
CONTINUED SURFACE HEATING AND MOISTENING WILL ALLOW SBCAPE VALUES
TO INCREASE TO 1000-2000 J/KG...WHILE DEEP SPEED SHEAR/
UNIDIRECTIONAL PROFILES WILL SUPPORT SUPERCELLS WITH A TENDENCY TO
EVOLVE INTO LINE SEGMENTS DURING THE AFTERNOON.  DAMAGING WINDS AND
LARGE HAIL WILL BE THE MAIN TRHEATS.


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 25040.


...THOMPSON

;414,0840 375,0860 375,0884 414,0870;

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