Alert archive / Georgia / Mesoscale Discussions in 2021

Mesoscale Discussion 1015

June 19, 202121 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Jun 19, 2021, 4:33 PM EDT for 21 counties in Georgia. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Jun 19, 2021, 4:33 PM EDT (20:33 UTC)
Expired
Jun 19, 2021, 6:00 PM EDT
In force
87 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 285
All 21 counties

Ben Hill County, GA, Clay County, GA, Coffee County, GA, Crisp County, GA, Dodge County, GA, Dooly County, GA, Dougherty County, GA, Irwin County, GA, Lee County, GA, Pulaski County, GA, Quitman County, GA, Randolph County, GA, Stewart County, GA, Sumter County, GA, Telfair County, GA, Terrell County, GA, Turner County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Worth County, GA

The radar

The Robins AFB radar (KJGX), 114 km from the middle of the area, began a volume at 20:34 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 8.6 hours before the alert went out and 161 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, Peachtre/Fal Fld, GA at 12:00Z on 2021-06-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 117 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, Peachtre/Fal Fld, GA at 12:00Z on 2021-06-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 square meters per square second.1939Sfc1 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
117 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1061 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

633 
ACUS11 KWNS 192034
SWOMCD
SPC MCD 192033 
GAZ000-ALZ000-192200-

Mesoscale Discussion 1015
NWS Storm Prediction Center Norman OK
0333 PM CDT Sat Jun 19 2021

Areas affected...far southeast AL...southwest into south-central GA

Concerning...Tornado Watch 285...

Valid 192033Z - 192200Z

The severe weather threat for Tornado Watch 285 continues.

SUMMARY...The most favorable corridor for a tornado will focus along
the maritime warm front/differential heating zone draped from west
to east across southern GA.  An additional tornado watch may be
considered towards the expiration time of tornado watch 285 (8pm
EDT) or if storms begin to exhibit tornadic supercell potential to
the east of tornado watch 285.

DISCUSSION...Scattered thunderstorms in a mix of discrete cells and
bands of deep convection continue to slowly shift to the northeast
across southeast AL/southwest GA.  A maritime warm
front/differential heating zone is stationary and draped from west
to east across southeast AL eastward into south-central GA.  As
stronger updrafts interact with this vorticity rich zone, a greater
probability for low-level mesocyclone development and a tornado risk
has been apparent so far this afternoon.  Expecting the relationship
of an increased threat for storm-scale rotation and the differential
heating zone to continue through the remainder of the afternoon and
perhaps into the early evening.  As the boundary layer slowly cools,
storm coverage will likely decrease this evening with the overall
conditional tornado risk to spatially contract and possibly become
quite limited by mid evening.

..Smith.. 06/19/2021

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

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

LAT...LON   32098537 32338390 32108260 31498271 31568528 32098537

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 19, 10:33 AM EDTTornado WatchSPCCalhoun, Chattahoochee, Clay, Early, Harris, Macon and 13 more9 hr
Jun 19, 2:13 PM EDTMesoscale DiscussionSPCCalhoun, Clay, Early, Randolph62 min
Jun 19, 7:22 PM EDTMesoscale DiscussionSPCBaker, Calhoun, Chattahoochee, Clay, Decatur, Dougherty and 17 more83 min

Nearby

Mesoscale 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.