Alert archive / Tennessee / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 297

May 13, 20114 states

The Storm Prediction Center issued this severe thunderstorm watch at May 13, 2011, 1:10 PM EDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 13, 2011, 1:10 PM EDT (17:10 UTC)
Expired: May 13, 2011, 7:00 PM EDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 88 counties

Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Dade County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Gilmer County, GA, Gordon County, GA, Habersham County, GA, Haralson County, GA, Lumpkin County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Towns County, GA, Union County, GA, Walker County, GA, White County, GA, Whitfield County, GA, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yancey County, NC, Anderson County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Loudon County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Washington County, TN, Bland County, VA, City of Bristol, VA, City of Galax, VA, City of Norton, VA, Grayson County, VA, Lee County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA

The radar

The Knoxville radar (KMRX), 36 km from the middle of the area, began a volume at 17:12 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: 10%
One or more EF2 to EF5 tornadoes: 2%
Ten or more severe wind reports: 40%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 13, 1:28 PM EDT	Severe Thunderstorm Warning	MRX	Bradley, McMinn, Polk	47 min
May 13, 1:46 PM EDT	Severe Thunderstorm Warning	FFC	Chattooga, Floyd	44 min
May 13, 2:07 PM EDT	Severe Thunderstorm Warning	RNK	Carroll, Grayson, Wythe, City of Galax	38 min
May 13, 2:09 PM EDT	Severe Thunderstorm Warning	MRX	Hancock, Hawkins	66 min
May 13, 2:33 PM EDT	Severe Thunderstorm Warning	MRX	Bradley, McMinn, Polk	42 min
May 13, 2:39 PM EDT	Flash Flood Warning	RNK	Carroll, Grayson, City of Galax	6 hr
May 13, 2:40 PM EDT	Severe Thunderstorm Warning	RNK	Carroll, Grayson, Wythe, City of Galax	51 min
May 13, 2:51 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Hawkins, Sullivan, Washington	54 min
May 13, 3:01 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Surry, Wilkes	59 min
May 13, 3:41 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Greene, Sullivan, Unicoi, Washington	64 min
May 13, 3:45 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Surry	60 min
May 13, 3:58 PM EDT	Severe Thunderstorm Warning	GSP	Buncombe, McDowell, Yancey	62 min
May 13, 3:58 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Cocke, Sevier	47 min
May 13, 4:10 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Johnson, Sullivan, Unicoi	65 min
May 13, 4:25 PM EDT	Severe Thunderstorm Warning	RNK	Smyth, Tazewell	65 min
May 13, 4:33 PM EDT	Severe Thunderstorm Warning	GSP	Burke, McDowell, Rutherford	57 min
May 13, 4:42 PM EDT	Severe Thunderstorm Warning	GSP	Avery, Burke, McDowell, Mitchell	42 min
May 13, 4:44 PM EDT	Severe Thunderstorm Warning	GSP	Burke, Caldwell	61 min
May 13, 4:45 PM EDT	Severe Thunderstorm Warning	RNK	Ashe, Watauga, Wilkes	60 min
May 13, 4:48 PM EDT	Severe Thunderstorm Warning	GSP	Buncombe, McDowell, Yancey	57 min
May 13, 4:56 PM EDT	Severe Thunderstorm Warning	GSP	Avery	34 min
May 13, 5:07 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Greene	26 min
May 13, 5:16 PM EDT	Severe Thunderstorm Warning	RNK	Grayson, Smyth, Wythe	59 min
May 13, 5:30 PM EDT	Severe Thunderstorm Warning	GSP	Burke, McDowell, Rutherford	60 min
May 13, 5:30 PM EDT	Flash Flood Warning	RNK	Ashe	6 hr
May 13, 5:35 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Ashe, Watauga, Wilkes	55 min
May 13, 6:05 PM EDT	Severe Thunderstorm Warning	GSP	Burke, Catawba, Cleveland, Lincoln	55 min
May 13, 6:19 PM EDT	Flash Flood Warning	RNK	Bland, Tazewell, Wythe	3 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, 5.2 hours before the alert went out and 276 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: 1225 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 983 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 13, 12:22 PM EDT	Mesoscale Discussion	SPC	Cherokee, Etowah	113 min
May 13, 6:03 PM EDT	Mesoscale Discussion	SPC	Colbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 8 more	57 min
May 13, 6:54 PM EDT	Severe Thunderstorm Watch	SPC	Colbert, Fayette, Franklin, Greene, Lamar, Lauderdale and 5 more	6 hr
May 13, 3:47 PM EDT	Mesoscale Discussion	SPC	Banks, Barrow, Bartow, Cherokee, Cobb, Dawson and 22 more	58 min
May 13, 4:44 PM EDT	Severe Thunderstorm Watch	SPC	Elbert, Franklin, Hart, Stephens	8 hr
May 13, 1:01 PM EDT	Mesoscale Discussion	SPC	Carlisle, Fulton, Graves, Hickman	89 min
May 13, 1:31 PM EDT	Severe Thunderstorm Watch	SPC	Ballard, Calloway, Carlisle, Fulton, Graves, Hickman and 3 more	6 hr
May 13, 3:44 PM EDT	Mesoscale Discussion	SPC	Ballard, Carlisle, Fulton, Graves, Hickman	2 hr
May 13, 4:36 PM EDT	Mesoscale Discussion	SPC	Alamance, Alexander, Alleghany, Anson, Ashe, Avery and 28 more	24 min
May 13, 7:21 PM EDT	Severe Thunderstorm Watch	SPC	Bladen, Cumberland, Duplin, Edgecombe, Franklin, Greene and 11 more	6 hr

Nearby

Severe Thunderstorm Watches in Tennessee, 2011 Severe Thunderstorm Watches in Georgia, 2011 Severe Thunderstorm Watches in North Carolina, 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; radar from the NEXRAD Level II archive.