Alert archive / Alabama / Tornado Watches in 2021

Tornado Watch 4

January 26, 202119 counties in Alabama; 9 counties in Georgia

The Storm Prediction Center issued this tornado watch at Jan 26, 2021, 12:37 AM CST for 19 counties in Alabama; 9 counties in Georgia. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jan 26, 2021, 12:37 AM CST (06:37 UTC)
Expired: Jan 26, 2021, 5:02 AM CST
In force: 4 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

All 28 counties

Bibb County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Etowah County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Marengo County, AL, Perry County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Bartow County, GA, Carroll County, GA, Cherokee County, GA, Cobb County, GA, Douglas County, GA, Floyd County, GA, Haralson County, GA, Paulding County, GA, Polk County, GA

The radar

The Birmingham radar (KBMX), 35 km from the middle of the area, began a volume at 06:37 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: 20%
Ten or more severe wind reports: 20%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 5%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 30%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jan 26, 1:07 AM CST	Severe Thunderstorm Warning	FFC	Bartow, Cherokee, Cobb, Paulding	38 min
Jan 26, 1:15 AM CST	Tornado Warning	FFC	Cherokee, Cobb, Paulding	15 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, 6.6 hours before the alert went out and 35 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: 232 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 913 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 371 m²/s²
0-3 km storm-relative helicity: 501 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

077 
WWUS20 KWNS 260634
SEL4  
SPC WW 260634
ALZ000-GAZ000-261200-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 4
NWS Storm Prediction Center Norman OK
1240 AM CST Tue Jan 26 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central and eastern Alabama
  Northwestern Georgia

* Effective this Tuesday morning from 1240 AM until 600 AM CST.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...A band of strong-severe thunderstorms with embedded
supercells will shift eastward over the watch area, offering tornado
and damaging-wind potential for at least a few more hours.

The tornado watch area is approximately along and 30 statute miles
either side of a line from 25 miles south of Tuscaloosa AL to 70
miles east northeast of Anniston 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 3...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 25035.

...Edwards

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 25, 9:19 PM CST	Mesoscale Discussion	SPC	Blount, Colbert, Cullman, Fayette, Franklin, Greene and 16 more	116 min
Jan 25, 11:40 PM CST	Mesoscale Discussion	SPC	Bibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 10 more	2 hr
Jan 26, 1:58 AM CST	Mesoscale Discussion	SPC	Bibb, Calhoun, Chilton, Clay, Cleburne, Coosa and 6 more	92 min

Nearby

Tornado Watches in Alabama, 2021 Tornado Watches in Georgia, 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.