Alert archive / Georgia / Mesoscale Discussions in 2021

Mesoscale Discussion 1021

June 19, 20218 counties in Alabama; 8 counties in Florida; 23 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Jun 19, 2021, 6:22 PM CDT for 8 counties in Alabama; 8 counties in Florida; 23 counties in Georgia. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Jun 19, 2021, 6:22 PM CDT (23:22 UTC)
Expired
Jun 19, 2021, 7:45 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 285
All 39 counties

Barbour County, AL, Bullock County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Macon County, AL, Russell County, AL, Bay County, FL, Calhoun County, FL, Gadsden County, FL, Holmes County, FL, Jackson County, FL, Leon County, FL, Liberty County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Chattahoochee County, GA, Clay County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Grady County, GA, Lee County, GA, Macon County, GA, Marion County, GA, Miller County, GA, Mitchell County, GA, Muscogee County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Seminole County, GA, Stewart County, GA, Sumter County, GA, Taylor County, GA, Terrell County, GA, Webster County, GA

The radar

The Ft Rucker radar (KEOX), 37 km from the middle of the area, began a volume at 23:22 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, 11.4 hours before the alert went out and 134 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 2021-06-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1367 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2021-06-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 147 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
1367 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
747 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
315 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.7

Open this sounding in Storm Lab

The text

As transmitted.

098 
ACUS11 KWNS 192322
SWOMCD
SPC MCD 192322 
GAZ000-FLZ000-ALZ000-200045-

Mesoscale Discussion 1021
NWS Storm Prediction Center Norman OK
0622 PM CDT Sat Jun 19 2021

Areas affected...western FL Panhandle...southeast AL...southwest GA

Concerning...Tornado Watch 285...

Valid 192322Z - 200045Z

The severe weather threat for Tornado Watch 285 continues.

SUMMARY...The risk for a few tornadoes associated with Tropical
Depression Claudette will continue through this evening and
overnight.  A new Tornado Watch will be needed prior to 00z.

DISCUSSION...Tropical Depression Claudette was located over
west-central AL, and continuing to move northeast (see latest NHC
Advisory for additional details).  Mesoanalysis and area VWP data
continue to show a favorable environment for low-level rotation with
0-1 km SRH of 150-200 m2/s2 across much of the current watch area. 
Short-range guidance suggests relatively strong 850-mb wind fields
of 40-45 kt will remain in place overnight across the area, and dew
points in the 70s will result in surface-based instability through
the  overnight hours.  Thus, conditions will remain favorable beyond
00z for a few tornadoes across southeast AL, the western FL
Panhandle and southwest GA, and a new Tornado Watch will be
coordinated prior to 00z.

..Bunting.. 06/19/2021

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

ATTN...WFO...FFC...TAE...BMX...

LAT...LON   29898511 30168581 30658603 31538583 31918577 32378578
            32638508 32668446 32558402 32448394 30218401 29898511

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 19, 1:08 AM CDTMesoscale DiscussionSPCBaldwin, Escambia, Mobile3 hr
Jun 19, 1:40 AM CDTTornado WatchSPCBaldwin, Butler, Conecuh, Covington, Crenshaw, Escambia and 3 more9 hr
Jun 19, 8:33 AM CDTMesoscale DiscussionSPCButler, Coffee, Conecuh, Covington, Crenshaw, Dale and 3 more57 min
Jun 19, 9:33 AM CDTTornado WatchSPCBarbour, Bullock, Butler, Coffee, Covington, Crenshaw and 10 more9 hr
Jun 19, 1:13 PM CDTMesoscale DiscussionSPCCalhoun, Clay, Early, Randolph62 min
Jun 19, 3:33 PM CDTMesoscale DiscussionSPCBen Hill, Clay, Coffee, Crisp, Dodge, Dooly and 15 more87 min

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.