Alert archive / Indiana / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 178

April 22, 201110 counties in Illinois; 32 counties in Indiana; 12 counties in Kentucky

The Storm Prediction Center issued this severe thunderstorm watch at Apr 22, 2011, 1:31 PM CDT for 10 counties in Illinois; 32 counties in Indiana; 12 counties in Kentucky. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 22, 2011, 1:31 PM CDT (18:31 UTC)
Expired
Apr 22, 2011, 6:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 54 counties

Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Jefferson County, IL, Saline County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Bartholomew County, IN, Brown County, IN, Clark County, IN, Crawford County, IN, Daviess County, IN, Dearborn County, IN, Decatur County, IN, Dubois County, IN, Floyd County, IN, Gibson County, IN, Greene County, IN, Harrison County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Monroe County, IN, Ohio County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Ripley County, IN, Scott County, IN, Spencer County, IN, Sullivan County, IN, Switzerland County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Bullitt County, KY, Carroll County, KY, Franklin County, KY, Gallatin County, KY, Henry County, KY, Jefferson County, KY, Meade County, KY, Oldham County, KY, Owen County, KY, Shelby County, KY, Spencer County, KY, Trimble County, KY

The radar

The Evansville,IN radar (KVWX), 40 km from the middle of the area, began a volume at 18:33 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 22, 2:08 PM CDTSevere Thunderstorm WarningINDClay, Daviess, Greene, Knox, Lawrence, Martin and 2 more35 min
Apr 22, 3:07 PM CDTSevere Thunderstorm WarningLMKCrawford, Perry23 min
Apr 22, 4:54 PM CDTSevere Thunderstorm WarningLMKBullitt, Jefferson, Shelby, Spencer36 min
Apr 22, 5:01 PM CDTTornado WarningLMKAnderson, Shelby, Spencer29 min
Apr 22, 5:25 PM CDTTornado WarningLMKAnderson, Franklin, Shelby, Spencer, Woodford35 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 6.5 hours before the alert went out and 206 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2011-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2011-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 585 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
845 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
585 m²/s²
0-3 km storm-relative helicity
683 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 10:09 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Franklin, Greene and 14 more66 min
Apr 22, 1:14 PM CDTMesoscale DiscussionSPCCrawford, Edwards, Jasper, Lawrence, Richland, Wabash61 min
Apr 22, 3:34 PM CDTTornado WatchSPCCalhoun, Greene, Jersey, Macoupin, Madison, Monroe and 2 more6 hr
Apr 22, 5:21 PM CDTMesoscale DiscussionSPCCalhoun, Greene, Jersey, Macoupin114 min
Apr 22, 5:27 PM CDTMesoscale DiscussionSPCClinton, Edwards, Franklin, Gallatin, Hamilton, Hardin and 18 more33 min
Apr 22, 5:49 PM CDTTornado WatchSPCAlexander, Bond, Clay, Clinton, Crawford, Edwards and 26 more7 hr
Apr 22, 3:48 PM CDTMesoscale DiscussionSPCClark, Jefferson, Ohio, Switzerland87 min

Nearby

Severe Thunderstorm Watches in Indiana, 2011Severe Thunderstorm Watches in Kentucky, 2011Severe Thunderstorm Watches in Illinois, 2011Every severe thunderstorm watch in 2011

Sources

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.