Alert archive / Tennessee / Tornado Watches in 2010

Tornado Watch 126

May 1, 201025 counties in Tennessee

The Storm Prediction Center issued this tornado watch at May 1, 2010, 6:35 PM EDT for 25 counties in Tennessee. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 1, 2010, 6:35 PM EDT (22:35 UTC)
Expired
May 1, 2010, 11:00 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 25 counties

Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Coffee County, TN, Cumberland County, TN, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Knox County, TN, Lincoln County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Sequatchie County, TN, Van Buren County, TN, Warren County, TN

The radar

The Northeast Alabama radar (KHTX), 90 km from the middle of the area, began a volume at 22:36 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
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 1, 6:45 PM EDTTornado WarningOHXCoffee, Grundy, Warren30 min
May 1, 6:57 PM EDTSevere Thunderstorm WarningHUNFranklin18 min
May 1, 7:02 PM EDTTornado WarningOHXCoffee, Grundy28 min
May 1, 7:08 PM EDTTornado WarningOHXBedford, Coffee22 min
May 1, 7:25 PM EDTTornado WarningHUNFranklin, Moore21 min
May 1, 8:00 PM EDTTornado WarningMRXBledsoe, Rhea45 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 112 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 2010-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 442 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 2010-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
442 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
592 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
303 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 1, 12:41 AM EDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 18 more64 min
May 1, 1:01 AM EDTTornado WatchSPCCarroll, Chester, Crockett, Dyer, Fayette, Gibson and 12 more3 hr
May 1, 3:25 AM EDTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 28 more95 min
May 1, 4:11 AM EDTTornado WatchSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 44 more8 hr
May 1, 7:17 AM EDTMesoscale DiscussionSPCBedford, Cannon, Chester, Clay, Davidson, Decatur and 29 more88 min
May 1, 8:48 AM EDTMesoscale DiscussionSPCCarroll, Chester, Crockett, Dyer, Fayette, Gibson and 12 more57 min
May 1, 10:52 AM EDTTornado WatchSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 37 more8 hr
May 1, 12:19 PM EDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Davidson, Decatur and 18 more56 min
May 1, 3:54 PM EDTMesoscale DiscussionSPCBedford, Benton, Bledsoe, Cannon, Carroll, Chester and 42 more66 min
May 1, 6:04 PM EDTMesoscale DiscussionSPCBedford, Bledsoe, Bradley, Chester, Coffee, Fayette and 17 more56 min

Nearby

Tornado Watches in Tennessee, 2010Every tornado watch in 2010

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.