Alert archive / Alabama / Mesoscale Discussions in 2021
Mesoscale Discussion 266
The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2021, 9:04 PM CDT for Coosa County, Randolph County, Tallapoosa County, Alabama. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Mar 25, 2021, 9:04 PM CDT (02:04 UTC)
- Expired
- Mar 25, 2021, 10:00 PM CDT
- In force
- 56 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 53
Counties Coosa County, AL, Randolph County, AL, Tallapoosa County, AL
The radar
The Maxwell AFB radar (KMXX), 53 km from the middle of the area, began a volume at 02:04 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 nearest sounding before it
Birmingham, AL (KBMX), launched 00:00Z, 2.1 hours before the alert went out and 81 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
- 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
The text
As transmitted.
196 ACUS11 KWNS 260205 SWOMCD SPC MCD 260204 GAZ000-ALZ000-260300- Mesoscale Discussion 0266 NWS Storm Prediction Center Norman OK 0904 PM CDT Thu Mar 25 2021 Areas affected...east-central AL Concerning...Tornado Watch 53... Valid 260204Z - 260300Z The severe weather threat for Tornado Watch 53 continues. SUMMARY...The greatest risk for a tornado will probably focus over east-central AL over the next 1-2 hours. The near-storm environment suggests a strong tornado is possible. DISCUSSION...Surface observations over east-central AL indicate dewpoints in the 67-68 deg F range with mid 70s temperatures. The 01z RAP forecast sounding from Maxwell AFB indicates 1500 J/kg MLCAPE with around 350 m2/s2 surface to 0.5 km SRH and is similar to the KMXX VAD data. Given the moist and strongly sheared wind profile, it seems likely the supercell over Chilton County will persist for several more hours. Although some risk for large hail could intermittently accompany this storm, it appears a tornado threat will be the primary concern---including the possibility for a strong tornado through 10pm CDT. The airmass has been relatively slow to moisten across parts of western GA. The risk for a tornado beyond the AL/GA into parts of western GA is more uncertain later this evening. ..Smith.. 03/26/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FFC...BMX... LAT...LON 32878661 33378548 33238514 32998528 32638654 32878661
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, 7:57 PM CDT | Tornado Watch | SPC | Colbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more | 3 hr |
Nearby
Mesoscale Discussions in Alabama, 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.