Alert archive / Alabama / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 70
The Storm Prediction Center issued this severe thunderstorm watch at Mar 31, 2021, 11:19 AM CDT for 29 counties in Alabama; 15 counties in Mississippi. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2021, 11:19 AM CDT (16:19 UTC)
- Expired
- Mar 31, 2021, 5:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 44 counties
Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Butler County, AL, Chambers County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Coosa County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Greene County, AL, Hale County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Russell County, AL, Sumter County, AL, Tallapoosa County, AL, Washington County, AL, Wilcox County, AL, Clarke County, MS, Covington County, MS, Forrest County, MS, Greene County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Marion County, MS, Perry County, MS, Simpson County, MS, Smith County, MS, Wayne County, MS
The radar
The Maxwell AFB radar (KMXX), 131 km from the middle of the area, began a volume at 16:20 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 11:23 AM CDT | Severe Thunderstorm Warning | BMX | Greene | 15 min |
| Mar 31, 11:29 AM CDT | Severe Thunderstorm Warning | JAN | Covington, Simpson, Smith | 61 min |
| Mar 31, 12:13 PM CDT | Severe Thunderstorm Warning | JAN | Jasper, Jones | 47 min |
| Mar 31, 12:36 PM CDT | Severe Thunderstorm Warning | MOB | Wayne | 54 min |
| Mar 31, 12:51 PM CDT | Severe Thunderstorm Warning | MOB | Choctaw | 54 min |
| Mar 31, 12:57 PM CDT | Severe Thunderstorm Warning | JAN | Clarke | 22 min |
| Mar 31, 1:01 PM CDT | Tornado Warning | MOB | Choctaw | 9 min |
| Mar 31, 1:13 PM CDT | Severe Thunderstorm Warning | BMX | Marengo | 14 min |
| Mar 31, 1:29 PM CDT | Severe Thunderstorm Warning | MOB | Clarke | 61 min |
| Mar 31, 1:33 PM CDT | Severe Thunderstorm Warning | BMX | Marengo | 57 min |
| Mar 31, 1:43 PM CDT | Severe Thunderstorm Warning | MOB | Wilcox | 47 min |
| Mar 31, 1:45 PM CDT | Severe Thunderstorm Warning | MOB | Choctaw | 15 min |
| Mar 31, 2:14 PM CDT | Severe Thunderstorm Warning | MOB | Conecuh, Monroe, Wilcox | 61 min |
| Mar 31, 3:58 PM CDT | Severe Thunderstorm Warning | MOB | Butler, Crenshaw | 33 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, 4.3 hours before the alert went out and 142 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.
- Mixed-layer CAPE
- 455 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 527 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 273 m²/s²
- 0-3 km storm-relative helicity
- 283 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 3.5
The text
As transmitted.
563 WWUS20 KWNS 311616 SEL0 SPC WW 311616 ALZ000-MSZ000-312200- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 70 NWS Storm Prediction Center Norman OK 1120 AM CDT Wed Mar 31 2021 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and southern Alabama Southeast Mississippi * Effective this Wednesday morning and afternoon from 1120 AM until 500 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Thunderstorm clusters along a southeast-moving cold front will be capable of producing scattered damaging winds and a brief tornado through this afternoon. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 20 miles southeast of Auburn AL to 20 miles west northwest of Pine Belt MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25035. ...Grams
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 1:55 AM CDT | Mesoscale Discussion | SPC | Blount, Cullman, Fayette, Franklin, Lamar, Lawrence and 5 more | 2 hr |
| Mar 31, 10:57 AM CDT | Mesoscale Discussion | SPC | Autauga, Barbour, Bullock, Butler, Chambers, Choctaw and 17 more | 93 min |
| Mar 31, 2:15 PM CDT | Mesoscale Discussion | SPC | Barbour, Bullock, Butler, Clarke, Conecuh, Crenshaw and 4 more | 90 min |
| Mar 31, 2:52 PM CDT | Mesoscale Discussion | SPC | Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 2 more | 53 min |
| Mar 31, 3:12 PM CDT | Severe Thunderstorm Watch | SPC | Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more | 4 hr |
| Mar 31, 4:50 PM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Houston | 115 min |
| Mar 30, 9:55 PM CDT | Mesoscale Discussion | SPC | Bolivar, Calhoun, Carroll, Grenada, Humphreys, Lafayette and 11 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Alabama, 2021Severe Thunderstorm Watches in Mississippi, 2021Every severe thunderstorm 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.