Alert archive / Georgia / Mesoscale Discussions in 2021

Mesoscale Discussion 311

March 31, 20218 counties in Alabama; Holmes County, Santa Rosa County, Florida; 16 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2021, 2:52 PM CDT for 8 counties in Alabama; Holmes County, Santa Rosa County, Florida; 16 counties in Georgia. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Mar 31, 2021, 2:52 PM CDT (19:52 UTC)
Expired
Mar 31, 2021, 3:45 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%
All 26 counties

Baldwin County, AL, Coffee County, AL, Covington County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Holmes County, FL, Santa Rosa County, FL, Baker County, GA, Calhoun County, GA, Clay County, GA, Crisp County, GA, Dooly County, GA, Dougherty County, GA, Early County, GA, Lee County, GA, Macon County, GA, Miller County, GA, Pulaski County, GA, Randolph County, GA, Schley County, GA, Sumter County, GA, Terrell County, GA, Webster County, GA

The radar

The Ft Rucker radar (KEOX), 32 km from the middle of the area, began a volume at 19:56 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 7.9 hours before the alert went out and 154 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.

475 
ACUS11 KWNS 311953
SWOMCD
SPC MCD 311952 
GAZ000-FLZ000-ALZ000-312045-

Mesoscale Discussion 0311
NWS Storm Prediction Center Norman OK
0252 PM CDT Wed Mar 31 2021

Areas affected...southern Alabama...the northwest Florida Panhandle
into southwest Georgia

Concerning...Severe potential...Watch possible 

Valid 311952Z - 312045Z

Probability of Watch Issuance...40 percent

SUMMARY...Some threat for a few instances of locally strong wind
gusts and hail will persist next few hours, but confidence in a more
robust severe threat is not particularly high with southward extent
toward the Gulf Coast. Additional WW issuance will depend on
convective trends during the next hour. However,  portion of WW 70
can be locally extended farther south to include the far western FL
Panhandle.

DISCUSSION...Line of thunderstorms with a few embedded organized
structures continue to move southeast through southern AL at around
15-20 kt. This line is approaching the southwestern border of ww 70
where some severe threat may persist next couple hours. Farther east
across southwest GA, the potential for a more robust severe threat
is uncertain due to presence of a warmer mid-level inversion evident
on the TLH RAOB and weaker instability with eastern extent into
southern GA. These limiting factors suggest storms might begin to
struggle as they move farther east and southeast. Latest HRRR runs
weaken storms as they cross into the FL Panhandle and this does not
seem unreasonable.

..Dial/Grams.. 03/31/2021

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

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

LAT...LON   32318439 32518393 32338343 31828357 31298430 30938520
            30698641 30658779 30958790 31568533 32318439

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, 3:12 PM CDTSevere Thunderstorm WatchSPCBaldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more4 hr
Mar 31, 4:50 PM CDTMesoscale DiscussionSPCCoffee, Dale, Houston115 min
Mar 31, 5:24 PM CDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Effingham and 11 more2 hr

Nearby

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