Severe Thunderstorm Watch 102

Issued

Mar 23, 2012, 3:39 PM CDT (20:39 UTC)

Expired

Mar 23, 2012, 7:12 PM CDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Chicago radar (KLOT), 120 km from the middle of the area, began a volume at 20:39 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

20%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

40%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 336Mar 23, 3:17 PM CDT
• Mesoscale Discussion 338Mar 23, 5:08 PM CDT
• Mesoscale Discussion 340Mar 23, 7:01 PM CDT

889 
WWUS20 KWNS 232039
SEL2
SPC WW 232039
ILZ000-INZ000-240200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 102
NWS STORM PREDICTION CENTER NORMAN OK
440 PM EDT FRI MAR 23 2012

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

       NORTHEAST ILLINOIS
       NORTHWEST AND CENTRAL INDIANA

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 440 PM UNTIL
1000 PM EDT.

HAIL TO 1.5 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 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 65 MILES NORTHWEST
OF DANVILLE ILLINOIS TO 20 MILES NORTHEAST OF INDIANAPOLIS
INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

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 101...

DISCUSSION...STRONG/SEVERE STORMS ARE MOVING NEWD TOWARD NERN IL AND
WEST CENTRAL IN AT THIS TIME...ON THE LEADING EDGE OF DYNAMIC
FORCING ASSOCIATED WITH A COLD UPPER LOW MOVING EWD OVER ERN MO.
SATELLITE IMAGERY INDICATES AN ARC OF CLEARING IN ADVANCE OF THE
STORMS WHICH IS ALLOWING HEATING/DESTABILIZATION TO OCCUR IN THE
DOWNSTREAM ENVIRONMENT.  POTENTIAL FOR LARGE HAIL AND DAMAGING WIND
GUSTS WILL CONTINUE WITH THESE STORMS INTO THE EVENING HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM
MOTION VECTOR 21035.


...WEISS

Severe Thunderstorm Watches in Indiana, 2012Severe Thunderstorm Watches in Illinois, 2012Every severe thunderstorm watch in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.