Severe Thunderstorm Watch 296

Issued

May 24, 2012, 3:30 PM CDT (20:30 UTC)

Expired

May 24, 2012, 7:47 PM CDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

65 kt

The Quad Cities radar (KDVN), 140 km from the middle of the area, began a volume at 20:32 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

10%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 889May 24, 1:34 PM CDT
• Mesoscale Discussion 890May 24, 3:06 PM CDT
• Mesoscale Discussion 893May 24, 5:42 PM CDT

966 
WWUS20 KWNS 242034
SEL6
SPC WW 242034
IAZ000-ILZ000-WIZ000-250300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 296
NWS STORM PREDICTION CENTER NORMAN OK
335 PM CDT THU MAY 24 2012

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

       CENTRAL AND EASTERN IOWA
       EXTREME NORTHWEST ILLINOIS
       SOUTHWEST WISCONSIN

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 335 PM UNTIL
1000 PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES WEST
NORTHWEST OF LONEROCK WISCONSIN TO 35 MILES SOUTH SOUTHWEST OF
OTTUMWA IOWA.  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.

OTHER WATCH INFORMATION...CONTINUE...WW 295...

DISCUSSION...STORMS ARE DEVELOPING ALONG AN EWD MOVING COLD FRONT
OVER THE CENTRAL PARTS OF IA AND ACTIVITY IS EXPECTED TO INTENSIFY
THROUGH THE LATE AFTERNOON HOURS.  CONVECTION WILL BE MOVING INTO AN
ENVIRONMENT CHARACTERIZED BY SBCAPE OF 1500-2000 J/KG AND VERY
STRONG LOW AND MID LEVEL SHEAR.  LOW LEVEL INVERTED-V SOUNDINGS WILL
AID IN DEVELOPMENT OF STRONG DOWNDRAFTS...ESPECIALLY OVER ERN IA
WHERE DCAPE EXCEEDS 1000 J/KG.  DAMAGING WIND GUSTS AND OCCASIONAL
HAIL WILL BE THE PRIMARY SEVERE THREATS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 22040.


...WEISS

Severe Thunderstorm Watches in Iowa, 2012Severe Thunderstorm Watches in Wisconsin, 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.