Alert archive / Mississippi / Tornado Watches in 2021

Tornado Watch 29

March 17, 202131 counties in Alabama; 34 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Mar 17, 2021, 11:36 AM CDT for 31 counties in Alabama; 34 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Mar 17, 2021, 11:36 AM CDT (16:36 UTC)
Expired: Mar 17, 2021, 7:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center
Particularly dangerous situation: Yes
Largest hail expected: 3 in
Strongest gust expected: 70 kt

All 65 counties

Autauga County, AL, Bibb County, AL, Blount County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Clay County, AL, Colbert County, AL, Coosa County, AL, Cullman County, AL, Dallas County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lawrence County, AL, Marengo County, AL, Marion County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Wilcox County, AL, Winston County, AL, Attala County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Greene County, MS, Hinds County, MS, Itawamba County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Monroe County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Perry County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Wayne County, MS, Winston County, MS

The radar

The Birmingham radar (KBMX), 64 km from the middle of the area, began a volume at 16:38 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: 95%
One or more EF2 to EF5 tornadoes: 90%
Ten or more severe wind reports: 70%
One or more gusts of 65 knots or more: 60%
Ten or more severe hail reports: 60%
One or more hailstones of 2 inches or more: 60%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Mar 17, 11:58 AM CDT	Tornado Warning	MOB	Choctaw	47 min
Mar 17, 12:07 PM CDT	Tornado Warning Tornado observed	JAN	Clarke	53 min
Mar 17, 12:13 PM CDT	Tornado Warning	BMX	Dallas	47 min
Mar 17, 12:21 PM CDT	Severe Thunderstorm Warning	BMX	Fayette, Lamar, Marion	25 min
Mar 17, 12:22 PM CDT	Tornado Warning	JAN	Clarke, Lauderdale	54 min
Mar 17, 12:41 PM CDT	Tornado Warning	BMX	Autauga	64 min
Mar 17, 12:50 PM CDT	Tornado Warning	JAN	Copiah, Lawrence, Lincoln	55 min
Mar 17, 12:59 PM CDT	Tornado Warning	BMX	Greene, Sumter	61 min
Mar 17, 12:59 PM CDT	Severe Thunderstorm Warning	MOB	Choctaw	46 min
Mar 17, 1:00 PM CDT	Severe Thunderstorm Warning	JAN	Kemper, Lauderdale, Noxubee	45 min
Mar 17, 1:12 PM CDT	Tornado Warning	MOB	Choctaw	48 min
Mar 17, 1:18 PM CDT	Tornado Warning	BMX	Autauga, Chilton, Elmore	57 min
Mar 17, 1:28 PM CDT	Tornado Warning	JAN	Jones	15 min
Mar 17, 1:30 PM CDT	Tornado Warning	MOB	Wayne	45 min
Mar 17, 1:38 PM CDT	Tornado Warning	MOB	Choctaw	37 min
Mar 17, 1:40 PM CDT	Severe Thunderstorm Warning	BMX	Pickens, Tuscaloosa	28 min
Mar 17, 1:45 PM CDT	Tornado Warning	JAN	Jones	21 min
Mar 17, 1:52 PM CDT	Tornado Warning	BMX	Greene, Hale, Marengo, Sumter	41 min
Mar 17, 1:58 PM CDT	Tornado Warning	BMX	Marengo	62 min
Mar 17, 1:59 PM CDT	Tornado Warning	BMX	Greene, Hale	46 min
Mar 17, 2:02 PM CDT	Tornado Warning Tornado observed	BMX	Chilton, Coosa	58 min
Mar 17, 2:03 PM CDT	Severe Thunderstorm Warning	MOB	Wayne	42 min
Mar 17, 2:05 PM CDT	Severe Thunderstorm Warning	MOB	Choctaw, Clarke	40 min
Mar 17, 2:09 PM CDT	Tornado Warning	BMX	Marengo	66 min
Mar 17, 2:14 PM CDT	Tornado Warning	BMX	Jefferson, Walker	61 min
Mar 17, 2:16 PM CDT	Severe Thunderstorm Warning	MOB	Choctaw	44 min
Mar 17, 2:19 PM CDT	Flash Flood Warning	MOB	Choctaw, Clarke, Washington	6 hr
Mar 17, 2:20 PM CDT	Tornado Warning Tornado observed	BMX	Tuscaloosa	40 min
Mar 17, 2:33 PM CDT	Tornado Warning Tornado observed	BMX	Clay, Coosa, Talladega	42 min
Mar 17, 2:34 PM CDT	Severe Thunderstorm Warning	MOB	Choctaw, Clarke, Washington	56 min
Mar 17, 2:36 PM CDT	Tornado Warning	MOB	Clarke	39 min
Mar 17, 2:38 PM CDT	Tornado Warning	MOB	Choctaw	52 min
Mar 17, 2:44 PM CDT	Flash Flood Warning	BMX	Hale, Marengo, Perry	2 hr
Mar 17, 2:51 PM CDT	Flash Flood Warning	BMX	Jefferson	2 hr
Mar 17, 2:53 PM CDT	Tornado Warning Tornado observed	BMX	Tuscaloosa	52 min
Mar 17, 2:54 PM CDT	Tornado Warning	BMX	Dallas, Marengo, Perry	66 min
Mar 17, 2:58 PM CDT	Tornado Warning	BMX	Blount, Jefferson	34 min
Mar 17, 3:18 PM CDT	Tornado Warning	MEG	Itawamba, Prentiss, Tishomingo	27 min
Mar 17, 3:21 PM CDT	Tornado Warning	BMX	Tuscaloosa	54 min
Mar 17, 3:25 PM CDT	Flash Flood Warning	BMX	Tuscaloosa	2 hr
Mar 17, 3:28 PM CDT	Severe Thunderstorm Warning	MOB	Choctaw	47 min
Mar 17, 3:33 PM CDT	Severe Thunderstorm Warning	JAN	Covington, Jefferson Davis, Lawrence	42 min
Mar 17, 3:34 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson, Walker	56 min
Mar 17, 3:37 PM CDT	Tornado Warning	BMX	Marengo	38 min
Mar 17, 3:40 PM CDT	Tornado Warning	HUN	Colbert, Franklin	35 min
Mar 17, 3:46 PM CDT	Tornado Warning	MOB	Choctaw	44 min
Mar 17, 3:55 PM CDT	Severe Thunderstorm Warning	MOB	Wilcox	20 min
Mar 17, 3:58 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson	47 min
Mar 17, 3:58 PM CDT	Tornado Warning	BMX	Dallas, Perry	47 min
Mar 17, 4:00 PM CDT	Tornado Warning	MOB	Wilcox	14 min
Mar 17, 4:04 PM CDT	Tornado Warning	MOB	Choctaw, Washington	26 min
Mar 17, 4:07 PM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	26 min
Mar 17, 4:12 PM CDT	Tornado Warning	BMX	Dallas	48 min
Mar 17, 4:17 PM CDT	Tornado Warning Tornado observedConsiderable damage threat	MOB	Choctaw, Clarke	43 min
Mar 17, 4:28 PM CDT	Tornado Warning Tornado observed	BMX	Marengo	62 min
Mar 17, 4:34 PM CDT	Severe Thunderstorm Warning	JAN	Claiborne, Copiah, Hinds, Jefferson, Warren	56 min
Mar 17, 4:36 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson	54 min
Mar 17, 4:40 PM CDT	Tornado Warning	BMX	Autauga	50 min
Mar 17, 4:43 PM CDT	Tornado Warning	BMX	Dallas, Perry	47 min
Mar 17, 4:44 PM CDT	Flash Flood Warning	HUN	Cullman, Morgan	5 hr
Mar 17, 4:52 PM CDT	Tornado Warning	JAN	Copiah, Jefferson, Lincoln	37 min
Mar 17, 4:52 PM CDT	Flash Flood Warning	MEG	Itawamba, Lee, Prentiss, Tishomingo	4 hr
Mar 17, 4:56 PM CDT	Severe Thunderstorm Warning	MEG	Chickasaw, Itawamba, Lee, Pontotoc, Prentiss, Union	49 min
Mar 17, 5:00 PM CDT	Tornado Warning	BMX	Chilton	60 min
Mar 17, 5:15 PM CDT	Tornado Warning	BMX	Chilton	60 min
Mar 17, 5:15 PM CDT	Severe Thunderstorm Warning	MOB	Clarke	30 min
Mar 17, 5:15 PM CDT	Severe Thunderstorm Warning	JAN	Hinds, Madison, Rankin, Yazoo	64 min
Mar 17, 5:16 PM CDT	Tornado Warning Tornado observed	BMX	Blount	44 min
Mar 17, 5:20 PM CDT	Tornado Warning	MOB	Clarke, Wilcox	40 min
Mar 17, 5:20 PM CDT	Tornado Warning	JAN	Jasper, Smith	55 min
Mar 17, 5:23 PM CDT	Tornado Warning	BMX	Dallas, Marengo, Perry	67 min
Mar 17, 5:41 PM CDT	Tornado Warning	BMX	Marengo	23 min
Mar 17, 5:42 PM CDT	Tornado Warning	BMX	Chilton, Coosa, Shelby, Talladega	48 min
Mar 17, 5:45 PM CDT	Severe Thunderstorm Warning	JAN	Jefferson Davis, Lawrence, Marion	34 min
Mar 17, 5:45 PM CDT	Severe Thunderstorm Warning	MEG	Chickasaw, Itawamba, Lee, Monroe	45 min
Mar 17, 5:48 PM CDT	Tornado Warning	BMX	Blount	42 min
Mar 17, 5:53 PM CDT	Tornado Warning	MOB	Wilcox	37 min
Mar 17, 5:54 PM CDT	Flash Flood Warning	MOB	Clarke, Wilcox	6 hr
Mar 17, 5:55 PM CDT	Severe Thunderstorm Warning	JAN	Attala, Choctaw, Holmes, Leake, Montgomery, Neshoba and 2 more	65 min
Mar 17, 5:55 PM CDT	Tornado Warning	MEG	Chickasaw, Itawamba, Lee, Monroe	35 min
Mar 17, 5:59 PM CDT	Severe Thunderstorm Warning	MOB	Clarke, Wilcox	46 min
Mar 17, 6:05 PM CDT	Severe Thunderstorm Warning	JAN	Leake, Neshoba, Newton, Scott	55 min
Mar 17, 6:08 PM CDT	Tornado Warning	MOB	Wilcox	22 min
Mar 17, 6:09 PM CDT	Tornado Warning	BMX	Chilton, Coosa, Shelby, Talladega	13 min
Mar 17, 6:12 PM CDT	Severe Thunderstorm Warning	JAN	Covington, Simpson, Smith	48 min
Mar 17, 6:13 PM CDT	Severe Thunderstorm Warning	JAN	Forrest, Lamar	47 min
Mar 17, 6:19 PM CDT	Severe Thunderstorm Warning	MOB	Greene, Perry, Wayne	56 min
Mar 17, 6:28 PM CDT	Severe Thunderstorm Warning	JAN	Jasper, Jones	48 min
Mar 17, 6:28 PM CDT	Severe Thunderstorm Warning	MEG	Itawamba, Monroe	47 min
Mar 17, 6:40 PM CDT	Flash Flood Warning	BMX	Walker, Winston	3 hr
Mar 17, 6:42 PM CDT	Severe Thunderstorm Warning	JAN	Choctaw, Clay, Kemper, Lowndes, Neshoba, Noxubee and 3 more	76 min
Mar 17, 6:44 PM CDT	Tornado Warning	HUN	Cullman	31 min
Mar 17, 6:48 PM CDT	Tornado Warning	BMX	Dallas	42 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

Birmingham, AL (KBMX), launched 12:00Z, 4.6 hours before the alert went out and 63 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: 658 J/kg
Mixed-layer CIN: -112 J/kg
Mixed-layer LCL: 759 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 169 m²/s²
0-3 km storm-relative helicity: 301 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

132 
WWUS20 KWNS 171633
SEL9  
SPC WW 171633
ALZ000-MSZ000-180000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 29
NWS Storm Prediction Center Norman OK
1135 AM CDT Wed Mar 17 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Western and central Alabama
  Central to eastern Mississippi

* Effective this Wednesday morning and evening from 1135 AM until
  700 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

* Primary threats include...
  Numerous tornadoes expected with a few intense tornadoes likely
  Scattered damaging winds and isolated significant gusts to 80
    mph likely
  Scattered large hail and isolated very large hail events to 3
    inches in diameter likely

SUMMARY...Numerous discrete supercells are expected to develop this
afternoon capable of producing strong to intense tornadoes.

The tornado watch area is approximately along and 80 statute miles
east and west of a line from 70 miles northwest of Gadsden AL to 35
miles southeast of Pine Belt MS. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU9).

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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 26...WW 27...WW 28...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 3 inches. Extreme turbulence and surface wind
gusts to 70 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 24030.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 17, 10:56 AM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Choctaw, Clarke, Coosa and 17 more	2 hr
Mar 17, 12:02 PM CDT	Mesoscale Discussion	SPC	Choctaw, Clarke, Marengo	58 min
Mar 17, 1:01 PM CDT	Mesoscale Discussion	SPC	Autauga, Chilton, Coosa, Elmore, Lowndes, Montgomery and 1 more	89 min
Mar 17, 1:26 PM CDT	Tornado Watch	SPC	Calhoun, Chambers, Cherokee, Cleburne, Elmore, Etowah and 7 more	5 hr
Mar 17, 1:45 PM CDT	Mesoscale Discussion	SPC	Mobile	90 min
Mar 17, 2:24 PM CDT	Mesoscale Discussion	SPC	Bibb, Chilton, Dallas, Hale, Marengo, Perry	96 min
Mar 17, 5:49 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Bullock, Butler, Calhoun and 32 more	86 min
Mar 17, 6:09 PM CDT	Mesoscale Discussion	SPC	Colbert, Franklin, Lamar, Lauderdale, Lawrence, Marion	66 min
Mar 17, 6:48 PM CDT	Tornado Watch PDS	SPC	Autauga, Baldwin, Barbour, Bibb, Blount, Bullock and 44 more	8 hr
Mar 17, 5:34 AM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Bolivar, Calhoun, Coahoma, DeSoto and 15 more	86 min
Mar 17, 5:53 AM CDT	Tornado Watch	SPC	Alcorn, Benton, Bolivar, Calhoun, Chickasaw, Coahoma and 20 more	7 hr
Mar 17, 7:38 AM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Coahoma, DeSoto, Itawamba, Lafayette and 11 more	67 min
Mar 17, 12:15 PM CDT	Mesoscale Discussion	SPC	Bolivar, Calhoun, Carroll, Claiborne, Coahoma, Grenada and 22 more	90 min
Mar 17, 12:57 PM CDT	Tornado Watch PDS	SPC	Adams, Alcorn, Benton, Bolivar, Calhoun, Carroll and 32 more	6 hr
Mar 17, 1:19 PM CDT	Mesoscale Discussion	SPC	Jefferson Davis, Lawrence, Lincoln, Simpson, Smith	86 min
Mar 17, 2:38 PM CDT	Tornado Watch	SPC	Amite, Hancock, Harrison, Jackson, Pearl River, Pike and 2 more	8 hr
Mar 17, 2:56 PM CDT	Mesoscale Discussion	SPC	Adams, Attala, Bolivar, Calhoun, Carroll, Chickasaw and 41 more	94 min

Nearby

Tornado Watches in Mississippi, 2021 Tornado Watches in Alabama, 2021 Every tornado watch in 2021

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.