Alert archive / Georgia / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 76

March 21, 20175 states

The Storm Prediction Center issued this severe thunderstorm watch at Mar 21, 2017, 2:33 PM CDT for 5 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Mar 21, 2017, 2:33 PM CDT (19:33 UTC)
Expired: Mar 21, 2017, 10:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 128 counties

Cherokee County, AL, DeKalb County, AL, Jackson County, AL, Lauderdale County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Banks County, GA, Barrow County, GA, Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Greene County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Haralson County, GA, Hart County, GA, Henry County, GA, Jackson County, GA, Lumpkin County, GA, Madison County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Taliaferro County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA, Wilkes County, GA, Cherokee County, NC, Clay County, NC, Graham County, NC, Jackson County, NC, Macon County, NC, Swain County, NC, Transylvania County, NC, Abbeville County, SC, Anderson County, SC, Cherokee County, SC, Greenville County, SC, Greenwood County, SC, Laurens County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, Union County, SC, Bedford County, TN, Benton County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Hardin County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Loudon County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Perry County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Sequatchie County, TN, Smith 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 Northeast Alabama radar (KHTX), 63 km from the middle of the area, began a volume at 19:31 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: 60%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 80%
One or more hailstones of 2 inches or more: 50%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Mar 21, 2:43 PM CDT	Severe Thunderstorm Warning	OHX	Hickman, Humphreys, Perry	47 min
Mar 21, 2:50 PM CDT	Severe Thunderstorm Warning	FFC	Banks, Hall, White	40 min
Mar 21, 3:14 PM CDT	Severe Thunderstorm Warning	OHX	Lewis, Perry, Wayne	46 min
Mar 21, 3:15 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Giles, Marshall, Maury	45 min
Mar 21, 3:21 PM CDT	Severe Thunderstorm Warning	OHX	Lawrence, Wayne	39 min
Mar 21, 3:25 PM CDT	Severe Thunderstorm Warning	OHX	Lawrence, Lewis, Perry, Wayne	39 min
Mar 21, 3:26 PM CDT	Severe Thunderstorm Warning	OHX	Hickman, Lewis, Maury	49 min
Mar 21, 3:26 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Giles, Marshall, Maury	49 min
Mar 21, 3:29 PM CDT	Severe Thunderstorm Warning	FFC	Hall, White	46 min
Mar 21, 3:29 PM CDT	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, Meigs	61 min
Mar 21, 3:37 PM CDT	Severe Thunderstorm Warning	GSP	Greenville	38 min
Mar 21, 3:47 PM CDT	Flash Flood Warning	OHX	Marshall, Maury	3 hr
Mar 21, 3:53 PM CDT	Severe Thunderstorm Warning	OHX	Giles, Lawrence, Lewis, Maury	37 min
Mar 21, 3:57 PM CDT	Severe Thunderstorm Warning	FFC	Murray, Whitfield	33 min
Mar 21, 3:58 PM CDT	Severe Thunderstorm Warning	OHX	Giles, Lawrence, Wayne	35 min
Mar 21, 4:00 PM CDT	Severe Thunderstorm Warning	OHX	Marshall, Maury	45 min
Mar 21, 4:04 PM CDT	Flash Flood Warning	FFC	Hall, White	6 hr
Mar 21, 4:05 PM CDT	Severe Thunderstorm Warning	GSP	Anderson, Oconee, Pickens	40 min
Mar 21, 4:07 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Marshall, Maury, Rutherford, Williamson	38 min
Mar 21, 4:09 PM CDT	Severe Thunderstorm Warning	FFC	Fannin, Lumpkin, Union	51 min
Mar 21, 4:09 PM CDT	Severe Thunderstorm Warning	HUN	Lincoln, Moore	36 min
Mar 21, 4:10 PM CDT	Severe Thunderstorm Warning	MRX	Bradley	39 min
Mar 21, 4:13 PM CDT	Severe Thunderstorm Warning	FFC	Banks, Hall, White	47 min
Mar 21, 4:14 PM CDT	Severe Thunderstorm Warning	GSP	Greenville, Spartanburg	46 min
Mar 21, 4:18 PM CDT	Severe Thunderstorm Warning	FFC	Dade, Walker	18 min
Mar 21, 4:20 PM CDT	Severe Thunderstorm Warning	MRX	McMinn, Meigs	19 min
Mar 21, 4:20 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Giles, Marshall, Maury	40 min
Mar 21, 4:28 PM CDT	Severe Thunderstorm Warning	GSP	Rabun	47 min
Mar 21, 4:30 PM CDT	Severe Thunderstorm Warning	MRX	Polk	60 min
Mar 21, 4:30 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Marshall, Rutherford	45 min
Mar 21, 4:33 PM CDT	Severe Thunderstorm Warning	HUN	Franklin, Lincoln, Moore	27 min
Mar 21, 4:41 PM CDT	Severe Thunderstorm Warning	FFC	Lumpkin, White	49 min
Mar 21, 4:41 PM CDT	Severe Thunderstorm Warning	GSP	Greenville	34 min
Mar 21, 4:42 PM CDT	Severe Thunderstorm Warning	OHX	Rutherford, Wilson	33 min
Mar 21, 4:52 PM CDT	Severe Thunderstorm Warning	FFC	Fannin, Lumpkin, Union	38 min
Mar 21, 4:57 PM CDT	Severe Thunderstorm Warning	HUN	Jackson, Madison	33 min
Mar 21, 4:59 PM CDT	Severe Thunderstorm Warning	FFC	Banks	46 min
Mar 21, 4:59 PM CDT	Severe Thunderstorm Warning	GSP	Greenville, Laurens, Spartanburg	46 min
Mar 21, 5:00 PM CDT	Severe Thunderstorm Warning	OHX	Cannon, Coffee, DeKalb, Grundy, Rutherford, Warren	30 min
Mar 21, 5:03 PM CDT	Tornado Warning	HUN	Franklin	12 min
Mar 21, 5:06 PM CDT	Flash Flood Warning	FFC	Dade, Walker	6 hr
Mar 21, 5:06 PM CDT	Severe Thunderstorm Warning	FFC	Fannin	24 min
Mar 21, 5:07 PM CDT	Severe Thunderstorm Warning	FFC	Dade, Walker	23 min
Mar 21, 5:14 PM CDT	Severe Thunderstorm Warning	GSP	Anderson, Greenville, Pickens	46 min
Mar 21, 5:15 PM CDT	Severe Thunderstorm Warning	GSP	Oconee, Pickens	45 min
Mar 21, 5:16 PM CDT	Severe Thunderstorm Warning	HUN	Jackson, Limestone, Madison	44 min
Mar 21, 5:20 PM CDT	Flash Flood Warning	FFC	Lumpkin, Union, White	6 hr
Mar 21, 5:21 PM CDT	Severe Thunderstorm Warning	MRX	Marion	54 min
Mar 21, 5:26 PM CDT	Severe Thunderstorm Warning	HUN	Jackson	34 min
Mar 21, 5:27 PM CDT	Severe Thunderstorm Warning	MRX	Bledsoe, Sequatchie	48 min
Mar 21, 5:28 PM CDT	Severe Thunderstorm Warning	FFC	Lumpkin, Union	47 min
Mar 21, 5:29 PM CDT	Severe Thunderstorm Warning	OHX	Cannon, Coffee, DeKalb, Grundy, Van Buren, Warren and 1 more	46 min
Mar 21, 5:30 PM CDT	Severe Thunderstorm Warning	GSP	Cherokee, Spartanburg	45 min
Mar 21, 5:33 PM CDT	Severe Thunderstorm Warning	FFC	Fannin	42 min
Mar 21, 5:35 PM CDT	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, McMinn, Meigs, Polk	55 min
Mar 21, 5:38 PM CDT	Severe Thunderstorm Warning	FFC	Catoosa, Dade, Walker	37 min
Mar 21, 5:39 PM CDT	Severe Thunderstorm Warning	MRX	Loudon, Roane	66 min
Mar 21, 5:41 PM CDT	Severe Thunderstorm Warning	GSP	Franklin	49 min
Mar 21, 5:45 PM CDT	Severe Thunderstorm Warning	GSP	Greenville, Spartanburg	45 min
Mar 21, 5:49 PM CDT	Severe Thunderstorm Warning	GSP	Habersham	26 min
Mar 21, 5:50 PM CDT	Severe Thunderstorm Warning	MRX	Hamilton, Meigs, Rhea	55 min
Mar 21, 5:53 PM CDT	Severe Thunderstorm Warning	FFC	Clarke, Jackson, Madison	52 min
Mar 21, 5:53 PM CDT	Severe Thunderstorm Warning	MRX	Loudon	46 min
Mar 21, 6:08 PM CDT	Severe Thunderstorm Warning	FFC	Madison	37 min
Mar 21, 6:08 PM CDT	Severe Thunderstorm Warning	MRX	Blount, Knox	67 min
Mar 21, 6:11 PM CDT	Severe Thunderstorm Warning	FFC	Catoosa, Chattooga, Dade, Floyd, Gordon, Walker and 1 more	49 min
Mar 21, 6:14 PM CDT	Severe Thunderstorm Warning	OHX	Cumberland, Van Buren, Warren, White	19 min
Mar 21, 6:15 PM CDT	Severe Thunderstorm Warning	GSP	Greenville, Laurens, Spartanburg	45 min
Mar 21, 6:16 PM CDT	Severe Thunderstorm Warning	FFC	Fannin, Union	44 min
Mar 21, 6:21 PM CDT	Severe Thunderstorm Warning	FFC	Clarke, Madison, Oglethorpe	24 min
Mar 21, 6:23 PM CDT	Severe Thunderstorm Warning	MRX	Bradley, McMinn, Polk	46 min
Mar 21, 6:24 PM CDT	Severe Thunderstorm Warning	FFC	Barrow, Jackson, Oconee	36 min
Mar 21, 6:25 PM CDT	Severe Thunderstorm Warning	GSP	Elbert, Franklin, Hart	31 min
Mar 21, 6:33 PM CDT	Severe Thunderstorm Warning	FFC	Barrow, Gwinnett, Walton	42 min
Mar 21, 6:33 PM CDT	Severe Thunderstorm Warning	MRX	Blount, Knox, Sevier	42 min
Mar 21, 6:34 PM CDT	Severe Thunderstorm Warning	HUN	DeKalb, Marshall	26 min
Mar 21, 6:41 PM CDT	Severe Thunderstorm Warning	FFC	Gilmer, Murray	34 min
Mar 21, 6:45 PM CDT	Severe Thunderstorm Warning	FFC	Clarke, Jackson, Madison, Oconee, Oglethorpe	45 min
Mar 21, 6:45 PM CDT	Severe Thunderstorm Warning	MRX	Monroe	43 min
Mar 21, 6:48 PM CDT	Severe Thunderstorm Warning	FFC	Bartow, Chattooga, Fannin, Floyd, Gilmer, Gordon and 3 more	42 min
Mar 21, 6:48 PM CDT	Severe Thunderstorm Warning	GSP	Elbert	42 min
Mar 21, 7:02 PM CDT	Severe Thunderstorm Warning	FFC	Banks, Jackson, Madison	31 min
Mar 21, 7:05 PM CDT	Severe Thunderstorm Warning	MRX	Cherokee, Clay	55 min
Mar 21, 7:07 PM CDT	Severe Thunderstorm Warning	FFC	Dawson, Fannin, Gilmer, Hall, Lumpkin, Pickens and 3 more	38 min
Mar 21, 7:08 PM CDT	Severe Thunderstorm Warning	FFC	Morgan, Oconee, Walton	52 min
Mar 21, 7:08 PM CDT	Severe Thunderstorm Warning	MRX	Blount	52 min
Mar 21, 7:09 PM CDT	Severe Thunderstorm Warning	GSP	Graham, Swain	66 min
Mar 21, 7:14 PM CDT	Severe Thunderstorm Warning	FFC	Bartow, Cherokee, Cobb, Dawson, Floyd, Forsyth and 3 more	46 min
Mar 21, 7:16 PM CDT	Severe Thunderstorm Warning	GSP	Habersham, Rabun	59 min
Mar 21, 7:19 PM CDT	Flash Flood Warning	FFC	Clarke, Greene, Oconee, Oglethorpe, Taliaferro, Wilkes	6 hr
Mar 21, 7:30 PM CDT	Severe Thunderstorm Warning	GSP	Laurens	45 min
Mar 21, 7:40 PM CDT	Severe Thunderstorm Warning	FFC	Carroll, Clayton, Cobb, DeKalb, Douglas, Forsyth and 5 more	50 min
Mar 21, 7:44 PM CDT	Severe Thunderstorm Warning	FFC	Banks, Barrow, Forsyth, Gwinnett, Hall, Jackson and 2 more	46 min
Mar 21, 7:49 PM CDT	Severe Thunderstorm Warning	FFC	Greene, Oconee, Oglethorpe	41 min
Mar 21, 8:22 PM CDT	Severe Thunderstorm Warning	FFC	Barrow, Clarke, Greene, Jackson, Madison, Morgan and 5 more	38 min
Mar 21, 8:27 PM CDT	Severe Thunderstorm Warning	GSP	Elbert	48 min
Mar 21, 8:45 PM CDT	Severe Thunderstorm Warning	FFC	Glascock, Greene, Hancock, Morgan, Oglethorpe, Putnam and 4 more	45 min
Mar 21, 8:59 PM CDT	Severe Thunderstorm Warning	GSP	Buncombe, Haywood, Henderson, Transylvania	46 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, 7.6 hours before the alert went out and 116 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: 215 J/kg
Mixed-layer CIN: -332 J/kg
Mixed-layer LCL: 1125 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 207 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
Mar 21, 1:53 PM CDT	Mesoscale Discussion	SPC	Calhoun, Cherokee, Cleburne, Colbert, DeKalb, Etowah and 7 more	3 hr
Mar 21, 4:30 PM CDT	Mesoscale Discussion	SPC	Jackson	90 min
Mar 21, 6:47 PM CDT	Mesoscale Discussion	SPC	Burke, Clarke, Columbia, Elbert, Glascock, Greene and 17 more	58 min

Nearby

Severe Thunderstorm Watches in Georgia, 2017 Severe Thunderstorm Watches in Tennessee, 2017 Severe Thunderstorm Watches in South Carolina, 2017 Every severe thunderstorm 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.