Alert archive / Alabama / Mesoscale Discussions in 2021
Mesoscale Discussion 310
The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2021, 2:15 PM CDT for 10 counties in Alabama; Greene County, Perry County, Mississippi. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2021, 2:15 PM CDT (19:15 UTC)
- Expired
- Mar 31, 2021, 3:45 PM CDT
- In force
- 90 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 70
Counties Barbour County, AL, Bullock County, AL, Butler County, AL, Clarke County, AL, Conecuh County, AL, Crenshaw County, AL, Monroe County, AL, Pike County, AL, Russell County, AL, Washington County, AL, Greene County, MS, Perry County, MS
The radar
The Mobile radar (KMOB), 136 km from the middle of the area, began a volume at 19:16 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 12:00Z, 7.3 hours before the alert went out and 183 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
- 455 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 527 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 273 m²/s²
- 0-3 km storm-relative helicity
- 283 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 3.5
The text
As transmitted.
367
ACUS11 KWNS 311916
SWOMCD
SPC MCD 311915
ALZ000-MSZ000-312045-
Mesoscale Discussion 0310
NWS Storm Prediction Center Norman OK
0215 PM CDT Wed Mar 31 2021
Areas affected...southeast Mississippi through southern Alabama
Concerning...Severe Thunderstorm Watch 70...
Valid 311915Z - 312045Z
The severe weather threat for Severe Thunderstorm Watch 70
continues.
SUMMARY...Threat for mainly isolated damaging wind and some hail
will persist next couple of hours from southeast Mississippi through
southern Alabama.
DISCUSSION...As of mid afternoon a line of thunderstorms extends
from near the GA/AL border southwest to south of Selma AL to near
Hattiesburg in southeast MS. The overall line movement is southeast
at 15-20 mph while individual convective elements move more rapidly
east northeast. In the short term (through about 20Z) the greatest
threat for strong to damaging wind appears to be just downstream
from the more organized storm cluster in southwest AL where some
bowing segments have been observed. Storms in southeast AL so far
have had a tendency to be undercut by the outflow boundary. However,
the severe threat in this area may soon increase given short-term
trends showing a tendency for storms to organize near Montgomery.
Surface temperatures have warmed into the low 80s F with low 60s
dewpoints in the warm sector supporting 800-1500 J/kg MLCAPE. While
low-level winds remain weak, shear through a deep layer will
continue to support the potential for embedded organized structures
capable of mainly damaging wind and hail through 21Z.
..Dial.. 03/31/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TAE...BMX...MOB...JAN...LIX...
LAT...LON 31078940 31238890 31788771 31988712 32178642 32318544
32318500 31788523 31458590 31148762 30778926 31078940SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 1:55 AM CDT | Mesoscale Discussion | SPC | Blount, Cullman, Fayette, Franklin, Lamar, Lawrence and 5 more | 2 hr |
| Mar 31, 10:57 AM CDT | Mesoscale Discussion | SPC | Autauga, Barbour, Bullock, Butler, Chambers, Choctaw and 17 more | 93 min |
| Mar 31, 11:19 AM CDT | Severe Thunderstorm Watch | SPC | Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 23 more | 6 hr |
| Mar 31, 2:52 PM CDT | Mesoscale Discussion | SPC | Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 2 more | 53 min |
| Mar 31, 3:12 PM CDT | Severe Thunderstorm Watch | SPC | Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more | 4 hr |
| Mar 31, 4:50 PM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Houston | 115 min |
| Mar 30, 9:55 PM CDT | Mesoscale Discussion | SPC | Bolivar, Calhoun, Carroll, Grenada, Humphreys, Lafayette and 11 more | 2 hr |
Nearby
Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Mississippi, 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.