Alert archive / Tennessee / Tornado Watches in 2013

Tornado Watch 100

April 11, 201314 counties in North Carolina; 36 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Apr 11, 2013, 6:36 PM EDT for 14 counties in North Carolina; 36 counties in Tennessee. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 11, 2013, 6:36 PM EDT (22:36 UTC)
Expired
Apr 12, 2013, 2:00 AM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 50 counties

Avery County, NC, Buncombe County, NC, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, Mitchell County, NC, Swain County, NC, Transylvania County, NC, Yancey County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Cumberland County, TN, Grainger County, TN, Greene County, TN, Grundy 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, Marion 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, Sequatchie County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Washington County, TN

The radar

The Knoxville radar (KMRX), 36 km from the middle of the area, began a volume at 22:37 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 11, 6:45 PM EDTSevere Thunderstorm WarningMRXBradley, McMinn60 min
Apr 11, 6:52 PM EDTSevere Thunderstorm WarningMRXBledsoe, Hamilton, Marion, Rhea, Sequatchie53 min
Apr 11, 7:47 PM EDTSevere Thunderstorm WarningMRXPolk43 min
Apr 11, 9:01 PM EDTSevere Thunderstorm WarningMRXCherokee29 min
Apr 11, 9:33 PM EDTSevere Thunderstorm WarningGSPTransylvania42 min
Apr 11, 10:56 PM EDTSevere Thunderstorm WarningGSPHaywood, Jackson, Macon, Transylvania64 min
Apr 11, 11:52 PM EDTFlash Flood WarningGSPTransylvania4 hr
Apr 11, 11:54 PM EDTSevere Thunderstorm WarningMRXCarter, Greene, Hawkins, Johnson, Sullivan, Washington66 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 12:00Z, 10.6 hours before the alert went out and 259 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, Nashville Metro, TN at 12:00Z on 2013-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Nashville Metro, TN at 12:00Z on 2013-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 256 square meters per square second.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1408 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
256 m²/s²
0-3 km storm-relative helicity
259 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 11, 6:06 PM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Haywood, Jackson, Macon and 2 more84 min
Apr 10, 8:55 PM EDTMesoscale DiscussionSPCDyer, Lake, Lauderdale, Obion, Weakley95 min
Apr 10, 9:28 PM EDTTornado WatchSPCCarroll, Chester, Crockett, Dyer, Fayette, Gibson and 11 more7 hr
Apr 11, 12:08 AM EDTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Gibson, Hardeman, Haywood and 7 more97 min
Apr 11, 11:41 AM EDTMesoscale DiscussionSPCBedford, Cannon, Giles, Lawrence, Lincoln, Marshall and 3 more2 hr
Apr 11, 12:56 PM EDTTornado WatchSPCFranklin, Lincoln, Moore7 hr
Apr 11, 1:34 PM EDTSevere Thunderstorm WatchSPCBedford, Cannon, Clay, Coffee, Cumberland, DeKalb and 17 more6 hr
Apr 11, 3:21 PM EDTMesoscale DiscussionSPCLincoln84 min
Apr 11, 3:59 PM EDTMesoscale DiscussionSPCBedford, Bledsoe, Cannon, Clay, Coffee, Cumberland and 26 more91 min

Nearby

Tornado Watches in Tennessee, 2013Tornado Watches in North Carolina, 2013Every tornado watch in 2013

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.