Alert archive / Alabama / Mesoscale Discussions in 2021
Mesoscale Discussion 34
The Storm Prediction Center issued this mesoscale discussion at Jan 25, 2021, 9:19 PM CST for 22 counties in Alabama; 19 counties in Mississippi; 8 counties in Tennessee. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Jan 25, 2021, 9:19 PM CST (03:19 UTC)
- Expired
- Jan 25, 2021, 11:15 PM CST
- In force
- 116 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 3
All 49 counties
Blount County, AL, Colbert County, AL, Cullman County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Attala County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Itawamba County, MS, Kemper County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Tishomingo County, MS, Webster County, MS, Winston County, MS, Franklin County, TN, Giles County, TN, Hardin County, TN, Lawrence County, TN, Lincoln County, TN, Marion County, TN, Moore County, TN, Wayne County, TN
The radar
The Columbus AFB radar (KGWX), 25 km from the middle of the area, began a volume at 03:21 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Birmingham, AL (KBMX), launched 00:00Z, 3.3 hours before the alert went out and 157 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
- 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
The text
As transmitted.
620 ACUS11 KWNS 260319 SWOMCD SPC MCD 260319 TNZ000-ALZ000-MSZ000-260515- Mesoscale Discussion 0034 NWS Storm Prediction Center Norman OK 0919 PM CST Mon Jan 25 2021 Areas affected...Portions of Mississippi...Alabama...Southern Tennessee Concerning...Tornado Watch 3... Valid 260319Z - 260515Z The severe weather threat for Tornado Watch 3 continues. SUMMARY...Severe threat continues across the eastern two-thirds of ww003. DISCUSSION...Multiple organized deeper circulations have been noted at times across ww003. One or two of these have attempted to produce tornadoes, especially with the supercell that is currently over eastern Pickens County AL. This activity has evolved within a modestly unstable air mass characterized by strong shear and seemingly favorable environment for possible tornadoes. Even so, the lack of strong large-scale forcing for ascent (primarily north of this region across the OH Valley) appears to be somewhat influential leading to the lack of more meaningful longer-lived supercells. Overall severe threat will gradually shift across central and eastern portions of the tornado watch over the next several hours. ..Darrow.. 01/26/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MRX...OHX...BMX...HUN...MEG...JAN... LAT...LON 32569032 35358819 35368537 32558760 32569032
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 25, 11:40 PM CST | Mesoscale Discussion | SPC | Bibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 10 more | 2 hr |
| Jan 26, 12:37 AM CST | Tornado Watch | SPC | Bibb, Calhoun, Cherokee, Chilton, Clay, Cleburne and 13 more | 4 hr |
| Jan 26, 1:58 AM CST | Mesoscale Discussion | SPC | Bibb, Calhoun, Chilton, Clay, Cleburne, Coosa and 6 more | 92 min |
Nearby
Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Mississippi, 2021Mesoscale Discussions in Tennessee, 2021Every mesoscale discussion 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.