Alert archive / Kentucky / Tornado Watches in 2009

Tornado Watch 109

April 2, 20094 states

The Storm Prediction Center issued this tornado watch at Apr 2, 2009, 2:40 PM CDT for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Apr 2, 2009, 2:40 PM CDT (19:40 UTC)
Expired: Apr 2, 2009, 7:08 PM CDT
In force: 4 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 57 counties

Gallatin County, IL, Hardin County, IL, Massac County, IL, Pope County, IL, Saline County, IL, White County, IL, Dubois County, IN, Gibson County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Allen County, KY, Breckinridge County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Edmonson County, KY, Graves County, KY, Grayson County, KY, Hancock County, KY, Henderson County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Webster County, KY, Benton County, TN, Cheatham County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Houston County, TN, Humphreys County, TN, Macon County, TN, Montgomery County, TN, Robertson County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Wilson County, TN

What SPC expected

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

Two or more tornadoes: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 2, 2:41 PM CDT	Severe Thunderstorm Warning	PAH	Johnson, Pope, Saline, Williamson	34 min
Apr 2, 2:45 PM CDT	Severe Thunderstorm Warning	OHX	Dickson	30 min
Apr 2, 2:53 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Dickson	37 min
Apr 2, 2:55 PM CDT	Tornado Warning	PAH	Calloway, Livingston, Lyon, Marshall, Trigg	35 min
Apr 2, 3:10 PM CDT	Severe Thunderstorm Warning	PAH	Franklin, Hamilton, Saline, Williamson	35 min
Apr 2, 3:12 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Dickson, Montgomery, Robertson	33 min
Apr 2, 3:19 PM CDT	Tornado Warning	OHX	Cheatham, Robertson	26 min
Apr 2, 3:35 PM CDT	Flash Flood Warning	PAH	Saline, Williamson	100 min
Apr 2, 3:44 PM CDT	Severe Thunderstorm Warning	PAH	Caldwell, Christian, Hopkins, Trigg	61 min
Apr 2, 3:46 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Williamson	29 min
Apr 2, 3:53 PM CDT	Tornado Warning	PAH	Muhlenberg	37 min
Apr 2, 3:56 PM CDT	Tornado Warning	OHX	Davidson, Sumner	34 min
Apr 2, 4:01 PM CDT	Flash Flood Warning	OHX	Dickson	3 hr
Apr 2, 4:08 PM CDT	Flash Flood Warning	OHX	Davidson, Williamson	7 hr
Apr 2, 4:14 PM CDT	Severe Thunderstorm Warning	PAH	Daviess, Henderson, McLean	46 min
Apr 2, 4:23 PM CDT	Tornado Warning	OHX	Sumner	22 min
Apr 2, 4:39 PM CDT	Tornado Warning	PAH	Vanderburgh, Warrick	51 min
Apr 2, 5:03 PM CDT	Tornado Warning	PAH	Warrick	42 min
Apr 2, 5:28 PM CDT	Flash Flood Warning	PAH	Daviess	92 min
Apr 2, 6:39 PM CDT	Flash Flood Warning	OHX	Sumner	4 hr
Apr 2, 6:55 PM CDT	Flash Flood Warning	OHX	Robertson	4 hr

Discussions around it

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

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 7.7 hours before the alert went out and 144 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 36 J/kg
Mixed-layer CIN: -191 J/kg
Mixed-layer LCL: 667 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 152 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 2, 2:04 PM CDT	Mesoscale Discussion	SPC	Gallatin, Hardin, Pope, Saline, Wabash, White	116 min
Apr 2, 4:35 PM CDT	Mesoscale Discussion	SPC	Bartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 19 more	85 min
Apr 2, 5:27 PM CDT	Tornado Watch	SPC	Bartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 19 more	3 hr
Apr 2, 5:36 PM CDT	Mesoscale Discussion	SPC	Fulton, Hickman	84 min
Apr 2, 10:53 AM CDT	Tornado Watch	SPC	Chester, Fayette, Hardeman, Hardin, McNairy, Shelby	4 hr
Apr 2, 1:09 PM CDT	Mesoscale Discussion	SPC	Bedford, Coffee, Franklin, Giles, Lawrence, Lincoln and 4 more	66 min
Apr 2, 1:33 PM CDT	Tornado Watch	SPC	Bedford, Giles, Hickman, Lawrence, Lewis, Lincoln and 7 more	5 hr
Apr 2, 3:42 PM CDT	Mesoscale Discussion	SPC	Bedford, Giles, Lawrence, Lewis, Lincoln, Marshall and 2 more	63 min
Apr 2, 5:25 PM CDT	Mesoscale Discussion	SPC	Anderson, Bledsoe, Blount, Bradley, Cumberland, Fentress and 20 more	95 min
Apr 2, 6:02 PM CDT	Tornado Watch	SPC	Anderson, Bedford, Benton, Bledsoe, Bradley, Campbell and 52 more	7 hr
Apr 2, 6:21 PM CDT	Tornado Watch	SPC	Carroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more	3 hr

Nearby

Tornado Watches in Kentucky, 2009 Tornado Watches in Tennessee, 2009 Tornado Watches in Indiana, 2009 Every tornado watch in 2009

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.