Alert archive / Kentucky / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 238

May 4, 201231 counties in Indiana; 34 counties in Kentucky

The Storm Prediction Center issued this severe thunderstorm watch at May 4, 2012, 2:29 PM EDT for 31 counties in Indiana; 34 counties in Kentucky. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 4, 2012, 2:29 PM EDT (18:29 UTC)
Expired
May 4, 2012, 7:41 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 65 counties

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, Switzerland County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Anderson County, KY, Boone County, KY, Boyle County, KY, Breckinridge County, KY, Bullitt County, KY, Carroll County, KY, Daviess County, KY, Fayette County, KY, Franklin County, KY, Gallatin County, KY, Garrard County, KY, Grant County, KY, Grayson County, KY, Hancock County, KY, Hardin County, KY, Henderson County, KY, Henry County, KY, Jefferson County, KY, Jessamine County, KY, Larue County, KY, Marion County, KY, McLean County, KY, Meade County, KY, Mercer County, KY, Nelson County, KY, Ohio County, KY, Oldham County, KY, Owen County, KY, Scott County, KY, Shelby County, KY, Spencer County, KY, Trimble County, KY, Washington County, KY, Woodford County, KY

The radar

The Louisville radar (KLVX), 64 km from the middle of the area, began a volume at 18:31 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
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 4, 2:45 PM EDTSevere Thunderstorm WarningPAHGibson, Posey30 min
May 4, 2:56 PM EDTSevere Thunderstorm WarningPAHGibson, Pike52 min
May 4, 3:15 PM EDTSevere Thunderstorm WarningLMKDubois45 min
May 4, 3:44 PM EDTSevere Thunderstorm WarningLMKCrawford, Dubois, Orange, Perry31 min
May 4, 4:09 PM EDTSevere Thunderstorm WarningLMKCrawford, Floyd, Harrison, Orange, Perry, Washington36 min
May 4, 4:33 PM EDTSevere Thunderstorm WarningLMKClark, Floyd, Harrison27 min
May 4, 4:57 PM EDTSevere Thunderstorm WarningLMKHarrison33 min
May 4, 5:23 PM EDTSevere Thunderstorm WarningLMKBullitt, Nelson, Spencer37 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

Cncnati-Daytn, OH (KILN), launched 12:00Z, 6.5 hours before the alert went out and 245 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, Cncnati-Daytn, OH at 12:00Z on 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 476 joules per kilogram.LCLLFCEL10008507005003002001001 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, Cncnati-Daytn, OH at 12:00Z on 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 square meters per square second.1939Sfc1 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
476 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
540 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
44 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
May 3, 11:29 PM EDTMesoscale DiscussionSPCBenton, Jasper, Lake, Newton, Porter61 min
May 4, 12:34 AM EDTSevere Thunderstorm WatchSPCBenton, Jasper, Newton5 hr
May 4, 3:16 AM EDTMesoscale DiscussionSPCBenton, Jasper, Newton, Pulaski, White119 min
May 4, 12:36 PM EDTMesoscale DiscussionSPCClark, Crawford, Daviess, Dubois, Floyd, Gibson and 11 more84 min
May 4, 4:16 PM EDTMesoscale DiscussionSPCClark, Crawford, Daviess, Dubois, Floyd, Gibson and 19 more59 min
May 4, 7:52 PM EDTMesoscale DiscussionSPCBoone, Delaware, Fayette, Franklin, Hamilton, Hancock and 12 more53 min
May 4, 1:26 PM EDTMesoscale DiscussionSPCTrumbull2 hr

Nearby

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

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.