Alert archive / Alabama / Tornado Watches in 2021

Tornado Watch 53

March 25, 202124 counties in Alabama

The Storm Prediction Center issued this tornado watch at Mar 25, 2021, 7:47 PM CDT for 24 counties in Alabama. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 25, 2021, 7:47 PM CDT (00:47 UTC)
Expired
Mar 25, 2021, 10:41 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 24 counties

Autauga County, AL, Bibb County, AL, Calhoun County, AL, Chambers County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Hale County, AL, Jefferson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL

The radar

The Birmingham radar (KBMX), 52 km from the middle of the area, began a volume at 00:49 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
30%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 25, 8:28 PM CDTSevere Thunderstorm WarningBMXBlount, Jefferson, St. Clair28 min
Mar 25, 8:33 PM CDTSevere Thunderstorm WarningBMXChilton42 min
Mar 25, 8:51 PM CDTSevere Thunderstorm WarningBMXBlount, Etowah, St. Clair25 min
Mar 25, 8:58 PM CDTSevere Thunderstorm WarningBMXCoosa49 min
Mar 25, 9:04 PM CDTTornado WarningBMXChilton, Coosa32 min
Mar 25, 9:51 PM CDTTornado WarningBMXChambers, Clay, Randolph, Tallapoosa54 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 00:00Z, 0.8 hours before the alert went out and 53 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-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2021-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1313 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2021-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 341 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
1313 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
662 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
341 m²/s²
0-3 km storm-relative helicity
334 m²/s²
Significant tornado parameter
3.1
Supercell composite
13.2

Open this sounding in Storm Lab

The text

As transmitted.

705 
WWUS20 KWNS 260043
SEL3  
SPC WW 260043
ALZ000-260600-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 53
NWS Storm Prediction Center Norman OK
745 PM CDT Thu Mar 25 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central Alabama

* Effective this Thursday night and Friday morning from 745 PM
  until 100 AM CDT.

* Primary threats include...
  A few tornadoes and a couple intense tornadoes possible
  Isolated damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...A cluster with embedded supercell structures should
progress east-northeast from west-central to east-central Alabama
offering a continued threat for a few tornadoes.

The tornado watch area is approximately along and 75 statute miles
east and west of a line from 25 miles northwest of Anniston AL to 30
miles south of Selma AL. For a complete depiction of the watch see
the associated watch outline update (WOUS64 KWNS WOU3).

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...

AVIATION...Tornadoes and 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 24035.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 25, 7:00 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 32 more30 min
Mar 25, 7:57 PM CDTTornado WatchSPCColbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more3 hr
Mar 25, 9:04 PM CDTMesoscale DiscussionSPCCoosa, Randolph, Tallapoosa56 min
Mar 25, 10:26 PM CDTMesoscale DiscussionSPCCoweta, Fayette, Heard64 min
Mar 25, 11:34 PM CDTMesoscale DiscussionSPCBarrow, Cherokee, Clarke, Clayton, Cobb, Coweta and 11 more56 min
Mar 26, 12:55 AM CDTTornado WatchSPCBanks, Barrow, Butts, Clarke, Clayton, Coweta and 31 more3 hr
Mar 26, 3:21 AM CDTMesoscale DiscussionSPCBarrow, Clarke, Clayton, Coweta, DeKalb, Elbert and 11 more54 min
Mar 26, 12:56 PM CDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Bryan, Bulloch, Burke and 44 more94 min

Nearby

Tornado Watches in Alabama, 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.