Alert archive / Alabama / Mesoscale Discussions in 2021

Mesoscale Discussion 312

March 31, 2021Coffee County, Dale County, Houston County, Alabama; Early County, Miller County, Seminole County, Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2021, 4:50 PM CDT for Coffee County, Dale County, Houston County, Alabama; Early County, Miller County, Seminole County, Georgia. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Mar 31, 2021, 4:50 PM CDT (21:50 UTC)
Expired
Mar 31, 2021, 6:45 PM CDT
In force
115 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 71

Counties Coffee County, AL, Dale County, AL, Houston County, AL, Early County, GA, Miller County, GA, Seminole County, GA

The radar

The Ft Rucker radar (KEOX), 21 km from the middle of the area, began a volume at 21:50 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 9.8 hours before the alert went out and 145 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, Tallahassee Rgnl, FL at 12:00Z on 2021-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 49 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2021-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.193958Sfc1 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
49 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
885 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

571 
ACUS11 KWNS 312151
SWOMCD
SPC MCD 312150 
GAZ000-FLZ000-ALZ000-312345-

Mesoscale Discussion 0312
NWS Storm Prediction Center Norman OK
0450 PM CDT Wed Mar 31 2021

Areas affected...southeast Alabama into southwest Georgia

Concerning...Severe Thunderstorm Watch 71...

Valid 312150Z - 312345Z

The severe weather threat for Severe Thunderstorm Watch 71
continues.

SUMMARY...A line of storms will continue east across the area, with
locally damaging wind gusts.

DISCUSSION...Radar shows an outflow boundary shifting southward
ahead of a squall line, extending from near EOX radar into southwest
GA. Enhanced lift exists where the leading outflow intersects the
main line, with the larger storms near and north of this
intersection. The primary damaging wind risk is likely to translate
east/southeast, or just south of the AL/GA outflow, as air north of
this boundary will be stabilized. Brief low-level rotation is also
possible near the outflow intersection, though the tornado threat is
expected to remain low as the more stable air undercuts the line
with time.

..Jewell.. 03/31/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TAE...MOB...

LAT...LON   31568584 31478548 31328451 31108452 30938479 30938503
            31158610 31288621 31398603 31568584

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 31, 1:55 AM CDTMesoscale DiscussionSPCBlount, Cullman, Fayette, Franklin, Lamar, Lawrence and 5 more2 hr
Mar 31, 10:57 AM CDTMesoscale DiscussionSPCAutauga, Barbour, Bullock, Butler, Chambers, Choctaw and 17 more93 min
Mar 31, 11:19 AM CDTSevere Thunderstorm WatchSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 23 more6 hr
Mar 31, 2:15 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Butler, Clarke, Conecuh, Crenshaw and 4 more90 min
Mar 31, 2:52 PM CDTMesoscale DiscussionSPCBaldwin, Coffee, Covington, Dale, Escambia, Geneva and 2 more53 min
Mar 31, 3:12 PM CDTSevere Thunderstorm WatchSPCBaldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more4 hr
Mar 31, 5:24 PM CDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Effingham and 11 more2 hr

Nearby

Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Georgia, 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.