Alert archive / Tennessee / Tornado Watches in 2020

Tornado Watch 12

January 11, 202013 counties in Alabama; 16 counties in Kentucky; 40 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Jan 11, 2020, 6:57 AM CST for 13 counties in Alabama; 16 counties in Kentucky; 40 counties in Tennessee. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jan 11, 2020, 6:57 AM CST (12:57 UTC)
Expired: Jan 11, 2020, 1:53 PM CST
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 0.5 in
Strongest gust expected: 60 kt

All 69 counties

Colbert County, AL, Cullman County, AL, Fayette County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Allen County, KY, Butler County, KY, Caldwell County, KY, Christian County, KY, Daviess County, KY, Hancock 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, Bedford County, TN, Cannon County, TN, Cheatham County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Giles County, TN, Grundy County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Moore County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 43 km from the middle of the area, began a volume at 13:00 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: 60%
One or more gusts of 65 knots or more: 20%
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: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jan 11, 7:01 AM CST	Tornado Warning	PAH	Trigg	29 min
Jan 11, 7:09 AM CST	Severe Thunderstorm Warning	OHX	Dickson, Hickman, Humphreys, Lewis, Perry, Wayne	36 min
Jan 11, 7:12 AM CST	Tornado Warning	PAH	Caldwell, Christian, Hopkins	33 min
Jan 11, 7:14 AM CST	Severe Thunderstorm Warning	HUN	Colbert, Lauderdale	61 min
Jan 11, 7:23 AM CST	Tornado Warning	PAH	Christian, Trigg	37 min
Jan 11, 7:29 AM CST	Flash Flood Warning	PAH	Christian, Daviess, McLean, Muhlenberg, Todd	5 hr
Jan 11, 7:29 AM CST	Tornado Warning	OHX	Humphreys	15 min
Jan 11, 7:31 AM CST	Severe Thunderstorm Warning	HUN	Franklin	59 min
Jan 11, 7:31 AM CST	Severe Thunderstorm Warning	PAH	McLean, Muhlenberg, Todd	44 min
Jan 11, 7:37 AM CST	Severe Thunderstorm Warning	OHX	Lawrence, Wayne	38 min
Jan 11, 7:39 AM CST	Severe Thunderstorm Warning	BMX	Lamar, Marion	66 min
Jan 11, 7:40 AM CST	Tornado Warning	PAH	Christian	20 min
Jan 11, 7:40 AM CST	Severe Thunderstorm Warning	OHX	Cheatham, Dickson, Houston, Humphreys, Montgomery, Robertson and 1 more	50 min
Jan 11, 7:42 AM CST	Severe Thunderstorm Warning	OHX	Cheatham, Dickson, Hickman, Humphreys, Lewis, Perry and 2 more	48 min
Jan 11, 7:57 AM CST	Severe Thunderstorm Warning	LMK	Butler, Logan, Ohio	33 min
Jan 11, 8:06 AM CST	Severe Thunderstorm Warning	OHX	Hickman, Lawrence, Lewis, Maury, Perry, Wayne	39 min
Jan 11, 8:07 AM CST	Severe Thunderstorm Warning	HUN	Colbert, Lauderdale, Lawrence	68 min
Jan 11, 8:13 AM CST	Severe Thunderstorm Warning	HUN	Franklin	62 min
Jan 11, 8:25 AM CST	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Dickson, Robertson, Sumner, Williamson	22 min
Jan 11, 8:34 AM CST	Severe Thunderstorm Warning	LMK	Butler, Logan, Warren	26 min
Jan 11, 8:42 AM CST	Severe Thunderstorm Warning	OHX	Giles, Lawrence, Lewis, Maury	33 min
Jan 11, 8:53 AM CST	Severe Thunderstorm Warning	OHX	Davidson, Hickman, Maury, Williamson	37 min
Jan 11, 8:59 AM CST	Severe Thunderstorm Warning	LMK	Logan, Warren	31 min
Jan 11, 9:07 AM CST	Severe Thunderstorm Warning	LMK	Allen, Simpson, Warren	23 min
Jan 11, 9:07 AM CST	Flash Flood Warning	OHX	Lawrence	3 hr
Jan 11, 9:11 AM CST	Severe Thunderstorm Warning	OHX	Giles, Lawrence, Marshall, Maury, Williamson	34 min
Jan 11, 9:22 AM CST	Severe Thunderstorm Warning	OHX	Davidson, Rutherford, Williamson, Wilson	38 min
Jan 11, 9:29 AM CST	Severe Thunderstorm Warning	OHX	Davidson, Sumner, Wilson	31 min
Jan 11, 9:43 AM CST	Severe Thunderstorm Warning	OHX	Giles, Marshall, Maury, Rutherford, Williamson	32 min
Jan 11, 10:17 AM CST	Severe Thunderstorm Warning	LMK	Allen, Barren, Hart	28 min
Jan 11, 10:20 AM CST	Severe Thunderstorm Warning	OHX	Smith, Wilson	25 min
Jan 11, 10:43 AM CST	Severe Thunderstorm Warning	OHX	DeKalb, Smith, Wilson	32 min
Jan 11, 10:47 AM CST	Severe Thunderstorm Warning	OHX	Clay, Jackson, Macon, Smith	28 min
Jan 11, 11:11 AM CST	Severe Thunderstorm Warning	OHX	Clay, Jackson, Overton	34 min
Jan 11, 11:14 AM CST	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lawrence	61 min
Jan 11, 11:27 AM CST	Severe Thunderstorm Warning	BMX	Fayette, Greene, Hale, Lamar, Marengo, Pickens and 2 more	63 min
Jan 11, 11:50 AM CST	Tornado Warning	BMX	Fayette	16 min
Jan 11, 12:01 PM CST	Severe Thunderstorm Warning	BMX	Bibb, Fayette, Jefferson, Shelby, Tuscaloosa, Walker	59 min
Jan 11, 12:07 PM CST	Severe Thunderstorm Warning	HUN	Morgan	53 min
Jan 11, 12:24 PM CST	Severe Thunderstorm Warning	BMX	Winston	36 min
Jan 11, 12:25 PM CST	Severe Thunderstorm Warning	HUN	Cullman	65 min
Jan 11, 12:35 PM CST	Tornado Warning	HUN	Cullman	25 min
Jan 11, 12:53 PM CST	Tornado Warning	HUN	Cullman	18 min
Jan 11, 1:01 PM CST	Severe Thunderstorm Warning	HUN	Cullman, Marshall, Morgan	39 min
Jan 11, 1:04 PM CST	Severe Thunderstorm Warning	HUN	Madison	35 min
Jan 11, 1:07 PM CST	Tornado Warning	HUN	Cullman, Marshall, Morgan	23 min
Jan 11, 1:24 PM CST	Tornado Warning	HUN	Jackson, Madison, Marshall	36 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, 1.0 hours before the alert went out and 38 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 819 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 633 m²/s²
0-3 km storm-relative helicity: 864 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.

Issued	Product	Office	Counties	Lasted
Jan 11, 6:12 AM CST	Mesoscale Discussion	SPC	Colbert, Lauderdale, Limestone, Madison	93 min
Jan 11, 7:39 AM CST	Mesoscale Discussion	SPC	Choctaw, Clarke, Greene, Hale, Marengo, Mobile and 3 more	96 min
Jan 11, 7:57 AM CST	Tornado Watch	SPC	Autauga, Baldwin, Bibb, Blount, Butler, Chilton and 22 more	9 hr
Jan 11, 9:28 AM CST	Mesoscale Discussion	SPC	Blount, Cullman, DeKalb, Fayette, Jackson, Lawrence and 7 more	92 min
Jan 11, 9:54 AM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Marengo, Pickens, Sumter, Washington	96 min
Jan 11, 11:50 AM CST	Mesoscale Discussion	SPC	Bibb, Blount, Chilton, Choctaw, Clarke, Cullman and 15 more	85 min
Jan 11, 12:20 PM CST	Mesoscale Discussion	SPC	Blount, Calhoun, Chambers, Cherokee, Clay, Cleburne and 9 more	85 min
Jan 11, 12:42 PM CST	Tornado Watch	SPC	Barbour, Bullock, Calhoun, Chambers, Cherokee, Clay and 15 more	7 hr
Jan 11, 1:15 PM CST	Mesoscale Discussion	SPC	Blount, Calhoun, Cherokee, Chilton, DeKalb, Etowah and 6 more	90 min
Jan 11, 2:26 PM CST	Mesoscale Discussion	SPC	Barbour, Bullock, Butler, Coffee, Covington, Crenshaw and 10 more	94 min
Jan 11, 2:44 PM CST	Tornado Watch	SPC	Coffee, Dale, Geneva, Henry, Houston	5 hr
Jan 11, 3:16 PM CST	Mesoscale Discussion	SPC	Bullock, Chambers, Clay, Cleburne, Lee, Macon and 3 more	89 min
Jan 11, 5:21 PM CST	Mesoscale Discussion	SPC	Houston	114 min
Jan 11, 8:20 AM CST	Mesoscale Discussion	SPC	Adair, Anderson, Barren, Boone, Boyle, Breckinridge and 45 more	55 min
Jan 11, 8:36 AM CST	Severe Thunderstorm Watch	SPC	Adair, Anderson, Barren, Bath, Boone, Bourbon and 62 more	7 hr
Jan 11, 11:35 AM CST	Mesoscale Discussion	SPC	Adair, Anderson, Bath, Bourbon, Boyle, Bracken and 48 more	85 min
Jan 11, 5:36 PM CST	Mesoscale Discussion	SPC	Letcher, Pike	84 min
Jan 10, 11:58 PM CST	Tornado Watch	SPC	Crockett, Dyer, Fayette, Gibson, Haywood, Lake and 4 more	7 hr
Jan 11, 3:52 AM CST	Mesoscale Discussion	SPC	Crockett, Dyer, Fayette, Hardeman, Haywood, Lauderdale and 3 more	83 min
Jan 11, 4:17 AM CST	Tornado Watch	SPC	Benton, Carroll, Chester, Decatur, Hardeman, Hardin and 5 more	6 hr
Jan 11, 5:06 AM CST	Mesoscale Discussion	SPC	Fayette, Hardeman, McNairy	54 min

Nearby

Tornado Watches in Tennessee, 2020 Tornado Watches in Kentucky, 2020 Tornado Watches in Alabama, 2020 Every tornado watch in 2020

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.