Alert archive / Tennessee / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 211

April 25, 20114 states

The Storm Prediction Center issued this severe thunderstorm watch at Apr 25, 2011, 11:42 PM CDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Apr 25, 2011, 11:42 PM CDT (04:42 UTC)
Expired: Apr 26, 2011, 7:00 AM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 77 counties

Colbert County, AL, Franklin County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Allen County, KY, Barren County, KY, Breckinridge County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Christian County, KY, Daviess County, KY, Edmonson County, KY, Grayson County, KY, Hancock County, KY, Hardin County, KY, Hart County, KY, Henderson County, KY, Hopkins County, KY, Logan County, KY, Lyon County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Warren County, KY, Webster County, KY, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Giles County, TN, Hardin County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Wayne County, TN, Williamson 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: 20%
One or more EF2 to EF5 tornadoes: 2%
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: 20%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 25, 11:45 PM CDT	Severe Thunderstorm Warning	MEG	Chester, Decatur, Fayette, Hardeman, Hardin, McNairy and 1 more	45 min
Apr 25, 11:54 PM CDT	Severe Thunderstorm Warning	OHX	Benton, Dickson, Hickman, Houston, Humphreys, Perry	51 min
Apr 25, 11:55 PM CDT	Severe Thunderstorm Warning	MEG	Carroll, Henry, Weakley	35 min
Apr 25, 11:59 PM CDT	Severe Thunderstorm Warning	MEG	Alcorn, Benton, Itawamba, Lafayette, Lee, Prentiss and 3 more	76 min
Apr 26, 12:01 AM CDT	Severe Thunderstorm Warning	MEG	Calhoun, Chickasaw, Lafayette, Lee, Pontotoc, Union and 1 more	59 min
Apr 26, 12:09 AM CDT	Tornado Warning	MEG	Alcorn, Tippah, Tishomingo	36 min
Apr 26, 12:13 AM CDT	Severe Thunderstorm Warning	MEG	Carroll, Chester, Decatur, Henderson	47 min
Apr 26, 12:14 AM CDT	Tornado Warning	MEG	Alcorn, Lee, Prentiss, Tippah, Union	31 min
Apr 26, 12:16 AM CDT	Tornado Warning	MEG	Lafayette, Pontotoc, Union	29 min
Apr 26, 12:23 AM CDT	Severe Thunderstorm Warning	OHX	Benton, Houston, Stewart	37 min
Apr 26, 12:24 AM CDT	Tornado Warning	MEG	Calhoun, Lafayette, Pontotoc	36 min
Apr 26, 12:26 AM CDT	Severe Thunderstorm Warning	PAH	Caldwell, Calloway, Christian, Livingston, Lyon, Marshall and 1 more	49 min
Apr 26, 12:28 AM CDT	Severe Thunderstorm Warning	MEG	Decatur, Hardin, McNairy	33 min
Apr 26, 12:32 AM CDT	Flash Flood Warning	PAH	Caldwell, Christian, Daviess, Henderson, Hopkins, McLean and 4 more	3 hr
Apr 26, 12:38 AM CDT	Severe Thunderstorm Warning	OHX	Hickman, Lawrence, Lewis, Perry, Wayne	37 min
Apr 26, 12:41 AM CDT	Tornado Warning	MEG	Chickasaw, Itawamba, Lee, Monroe, Pontotoc, Union	19 min
Apr 26, 12:43 AM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Dickson, Hickman, Houston, Humphreys, Montgomery and 3 more	32 min
Apr 26, 12:54 AM CDT	Tornado Warning	PAH	Caldwell, Crittenden, Union, Webster	36 min
Apr 26, 12:58 AM CDT	Severe Thunderstorm Warning	MEG	Calhoun, Chickasaw, Itawamba, Lee, Monroe, Pontotoc and 2 more	64 min
Apr 26, 1:02 AM CDT	Severe Thunderstorm Warning	PAH	Caldwell, Christian, Hopkins, Muhlenberg, Todd, Trigg	43 min
Apr 26, 1:04 AM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	41 min
Apr 26, 1:10 AM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Dickson, Hickman, Maury, Montgomery and 3 more	35 min
Apr 26, 1:13 AM CDT	Severe Thunderstorm Warning	LMK	Butler, Logan, Ohio, Simpson, Warren	32 min
Apr 26, 1:14 AM CDT	Severe Thunderstorm Warning	OHX	Hickman, Lawrence, Lewis, Maury, Perry, Wayne and 1 more	31 min
Apr 26, 1:20 AM CDT	Severe Thunderstorm Warning	PAH	Daviess, Henderson, Hopkins, McLean, Muhlenberg, Union and 1 more	40 min
Apr 26, 1:24 AM CDT	Tornado Warning	LMK	Logan	36 min
Apr 26, 1:39 AM CDT	Severe Thunderstorm Warning	OHX	Giles, Hickman, Lawrence, Lewis, Marshall, Maury and 3 more	36 min
Apr 26, 1:45 AM CDT	Severe Thunderstorm Warning	LMK	Allen, Butler, Edmonson, Grayson, Simpson, Warren	45 min
Apr 26, 1:49 AM CDT	Severe Thunderstorm Warning	PAH	Henderson	26 min
Apr 26, 1:52 AM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale, Lawrence	38 min
Apr 26, 2:11 AM CDT	Severe Thunderstorm Warning	OHX	Davidson, Rutherford, Sumner, Williamson, Wilson	34 min
Apr 26, 2:15 AM CDT	Severe Thunderstorm Warning	OHX	Bedford, Giles, Marshall, Maury, Rutherford, Williamson	34 min
Apr 26, 2:23 AM CDT	Severe Thunderstorm Warning	LMK	Grayson, Hardin, Hart, Larue	22 min
Apr 26, 2:38 AM CDT	Severe Thunderstorm Warning	LMK	Barren, Hart, Metcalfe	37 min
Apr 26, 2:47 AM CDT	Severe Thunderstorm Warning	LMK	Bullitt, Green, Hardin, Hart, Larue, Nelson and 1 more	28 min
Apr 26, 2:52 AM CDT	Severe Thunderstorm Warning	LMK	Allen, Barren, Metcalfe, Monroe	38 min
Apr 26, 3:18 AM CDT	Flash Flood Warning	MEG	Coahoma, Panola, Quitman, Tate, Tunica	3 hr
Apr 26, 6:32 AM CDT	Severe Thunderstorm Warning	MEG	Coahoma, Quitman, Tunica	30 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

Nashville Metro, TN (KBNA), launched 00:00Z, 4.7 hours before the alert went out and 97 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: 211 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 1752 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 25, 11:05 PM CDT	Mesoscale Discussion	SPC	Colbert, Franklin, Lauderdale	115 min
Apr 26, 2:04 AM CDT	Mesoscale Discussion	SPC	Lawrence, Limestone, Madison, Morgan, Winston	56 min
Apr 25, 7:34 PM CDT	Mesoscale Discussion	SPC	Ballard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 9 more	116 min
Apr 26, 12:49 PM CDT	Mesoscale Discussion	SPC	Martin	56 min
Apr 26, 2:41 PM CDT	Mesoscale Discussion	SPC	Ballard, Calloway, Carlisle, Fulton, Graves, Hickman and 2 more	94 min
Apr 26, 3:02 PM CDT	Tornado Watch PDS	SPC	Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more	7 hr
Apr 26, 4:38 PM CDT	Mesoscale Discussion	SPC	Breckinridge, Bullitt, Hancock, Henderson, Jefferson, Meade and 2 more	37 min
Apr 26, 4:50 PM CDT	Tornado Watch	SPC	Allen, Anderson, Barren, Breckinridge, Bullitt, Butler and 25 more	5 hr
Apr 26, 6:17 PM CDT	Mesoscale Discussion	SPC	Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 14 more	118 min
Apr 25, 9:23 PM CDT	Tornado Watch	SPC	Attala, Bolivar, Carroll, Grenada, Holmes, Humphreys and 10 more	7 hr
Apr 26, 10:51 AM CDT	Mesoscale Discussion	SPC	Coahoma, DeSoto, Marshall, Tate, Tunica	54 min

Nearby

Severe Thunderstorm Watches in Tennessee, 2011 Severe Thunderstorm Watches in Kentucky, 2011 Severe Thunderstorm Watches in Mississippi, 2011 Every 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.