Alert archive / Alabama / Tornado Watches in 2021
Tornado Watch 54
The Storm Prediction Center issued this tornado watch at Mar 25, 2021, 7:57 PM CDT for 10 counties in Alabama; 6 counties in Tennessee. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 25, 2021, 7:57 PM CDT (00:57 UTC)
- Expired
- Mar 25, 2021, 10:46 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 55 kt
Counties Colbert County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Franklin County, TN, Giles County, TN, Lawrence County, TN, Lincoln County, TN, Moore County, TN, Wayne County, TN
The radar
The Northeast Alabama radar (KHTX), 103 km from the middle of the area, began a volume at 00:58 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
- 40%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 40%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 25, 8:41 PM CDT | Severe Thunderstorm Warning | OHX | Bedford, Giles, Marshall, Maury, Rutherford | 34 min |
| Mar 25, 9:00 PM CDT | Severe Thunderstorm Warning | HUN | DeKalb, Marshall | 30 min |
| Mar 25, 9:26 PM CDT | Severe Thunderstorm Warning | HUN | DeKalb | 19 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 00:00Z, 1.0 hours before the alert went out and 144 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
- 290 J/kg
- Mixed-layer CIN
- -73 J/kg
- Mixed-layer LCL
- 615 m above ground
- 0-6 km bulk shear
- 85 kt
- 0-1 km storm-relative helicity
- 657 m²/s²
- 0-3 km storm-relative helicity
- 631 m²/s²
- Significant tornado parameter
- 1.0
- Supercell composite
- 7.4
The text
As transmitted.
673 WWUS20 KWNS 260055 SEL4 SPC WW 260055 ALZ000-TNZ000-260600- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 54 NWS Storm Prediction Center Norman OK 800 PM CDT Thu Mar 25 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far northern Alabama Far southern middle Tennessee * Effective this Thursday night and Friday morning from 800 PM until 100 AM CDT. * Primary threats include... A couple intense tornadoes possible Isolated damaging wind gusts to 65 mph possible SUMMARY...Trailing portion of a cluster with embedded supercells may progress along the Tennessee and Alabama border region through this evening, with a conditional risk for a strong tornado. The tornado watch area is approximately along and 35 statute miles north and south of a line from 30 miles west of Muscle Shoals AL to 60 miles east northeast of Huntsville AL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). 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 50...WW 51...WW 52...WW 53... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 24035. ...Grams
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 25, 7:00 PM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 32 more | 30 min |
| Mar 25, 7:47 PM CDT | Tornado Watch | SPC | Autauga, Bibb, Calhoun, Chambers, Chilton, Clay and 18 more | 3 hr |
| Mar 25, 9:04 PM CDT | Mesoscale Discussion | SPC | Coosa, Randolph, Tallapoosa | 56 min |
| Mar 25, 7:36 PM CDT | Mesoscale Discussion | SPC | Bedford, Cannon, Coffee, Davidson, DeKalb, Grundy and 11 more | 84 min |
| Mar 25, 9:07 PM CDT | Mesoscale Discussion | SPC | Bedford, Bledsoe, Cannon, Clay, Coffee, Cumberland and 18 more | 83 min |
| Mar 25, 9:26 PM CDT | Tornado Watch | SPC | Anderson, Bledsoe, Bradley, Campbell, Cumberland, Fentress and 14 more | 2 hr |
Nearby
Tornado Watches in Alabama, 2021Tornado Watches in Tennessee, 2021Every 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.