Alert archive / Tennessee / Tornado Watches in 2017

Tornado Watch 365

June 23, 20174 states

The Storm Prediction Center issued this tornado watch at Jun 23, 2017, 12:16 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 23, 2017, 12:16 PM CDT (17:16 UTC)
Expired
Jun 23, 2017, 5:47 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 82 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, St. Clair County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Floyd County, GA, Gordon County, GA, Murray County, GA, Walker County, GA, Whitfield County, GA, Lowndes County, MS, Noxubee County, MS, Oktibbeha County, MS, Winston County, MS, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Cannon County, TN, Claiborne County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Grundy County, TN, Hamilton County, TN, Jackson County, TN, Knox County, TN, Lawrence County, TN, Lincoln County, TN, Loudon County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Trousdale County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 25 km from the middle of the area, began a volume at 17:15 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 23, 12:16 PM CDTSevere Thunderstorm WarningBMXLamar, Marion59 min
Jun 23, 12:52 PM CDTSevere Thunderstorm WarningBMXFayette, Marion53 min
Jun 23, 1:13 PM CDTSevere Thunderstorm WarningHUNColbert, Franklin, Lawrence32 min
Jun 23, 1:15 PM CDTFlash Flood WarningHUNColbert, Lauderdale, Lawrence6 hr
Jun 23, 1:21 PM CDTTornado WarningHUNFranklin, Lawrence24 min
Jun 23, 1:26 PM CDTSevere Thunderstorm WarningBMXMarion, Winston49 min
Jun 23, 1:33 PM CDTSevere Thunderstorm WarningBMXFayette4 min
Jun 23, 1:40 PM CDTSevere Thunderstorm WarningHUNLawrence, Limestone, Morgan35 min
Jun 23, 1:47 PM CDTTornado WarningHUNLawrence28 min
Jun 23, 1:56 PM CDTSevere Thunderstorm WarningHUNCullman, Lawrence, Morgan34 min
Jun 23, 2:08 PM CDTSevere Thunderstorm WarningHUNLawrence, Limestone, Morgan19 min
Jun 23, 2:15 PM CDTSevere Thunderstorm WarningHUNLimestone, Madison30 min
Jun 23, 2:44 PM CDTSevere Thunderstorm WarningHUNMadison31 min
Jun 23, 2:47 PM CDTFlash Flood WarningHUNColbert, Franklin, Lawrence, Limestone, Morgan6 hr
Jun 23, 4:27 PM CDTSevere Thunderstorm WarningFFCBartow, Chattooga, Floyd, Gordon, Polk48 min
Jun 23, 4:35 PM CDTSevere Thunderstorm WarningBMXCalhoun, Cherokee, Cleburne40 min
Jun 23, 5:11 PM CDTSevere Thunderstorm WarningFFCBartow, Cherokee, Gilmer, Gordon, Murray, Pickens34 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, 5.3 hours before the alert went out and 118 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 2017-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 449 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 2017-06-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 232 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
449 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
232 m²/s²
0-3 km storm-relative helicity
224 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.1

Open this sounding in Storm Lab

The text

As transmitted.

453 
WWUS20 KWNS 231714
SEL5  
SPC WW 231714
ALZ000-GAZ000-MSZ000-TNZ000-240100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 365
NWS Storm Prediction Center Norman OK
1215 PM CDT Fri Jun 23 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Western and Northern Alabama
  Northwest Georgia
  Eastern Mississippi
  Middle and Eastern Tennessee

* Effective this Friday afternoon and evening from 1215 PM until
  800 PM CDT.

* Primary threats include...
  A few tornadoes possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...Preceding the east/northeastward-moving remnants of Cindy,
a very air mass and strong low/mid-level winds will support both
organized bowing structures and some line-preceding or embedded
supercells capable of a few tornadoes and locally damaging winds
this afternoon into early evening.

The tornado watch area is approximately along and 80 statute miles
east and west of a line from 45 miles north northeast of Crossville
TN to 20 miles south southwest of Tuscaloosa AL. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU5).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 0.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 24040.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 22, 8:57 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 47 more63 min
Jun 23, 10:54 AM CDTMesoscale DiscussionSPCBibb, Blount, Colbert, Cullman, Fayette, Franklin and 19 more96 min
Jun 23, 3:17 PM CDTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Chilton, Cullman and 15 more118 min
Jun 23, 2:04 PM CDTSevere Thunderstorm WatchSPCBenton, Calhoun, Coahoma, DeSoto, Lafayette, Marshall and 9 more6 hr
Jun 23, 4:35 PM CDTMesoscale DiscussionSPCCoahoma, DeSoto, Panola, Quitman, Tate, Tunica85 min

Nearby

Tornado Watches in Tennessee, 2017Tornado Watches in Alabama, 2017Tornado Watches in Georgia, 2017Every tornado watch in 2017

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.