Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 491
The Storm Prediction Center issued this mesoscale discussion at May 3, 2021, 1:03 PM EDT for 36 counties in Georgia; 10 counties in South Carolina. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- May 3, 2021, 1:03 PM EDT (17:03 UTC)
- Expired
- May 3, 2021, 2:30 PM EDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 127
All 46 counties
Barrow County, GA, Butts County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Coweta County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fayette County, GA, Fulton County, GA, Greene County, GA, Gwinnett County, GA, Hancock County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Lamar County, GA, Lincoln County, GA, Madison County, GA, McDuffie County, GA, Monroe County, GA, Morgan County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pike County, GA, Putnam County, GA, Rockdale County, GA, Spalding County, GA, Taliaferro County, GA, Walton County, GA, Warren County, GA, Wilkes County, GA, Abbeville County, SC, Chester County, SC, Edgefield County, SC, Fairfield County, SC, Greenwood County, SC, Laurens County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Saluda County, SC
The radar
The Atlanta radar (KFFC), 114 km from the middle of the area, began a volume at 17:02 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, 5.1 hours before the alert went out and 108 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
- 674 J/kg
- Mixed-layer CIN
- -54 J/kg
- Mixed-layer LCL
- 671 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 207 m²/s²
- 0-3 km storm-relative helicity
- 272 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 4.8
The text
As transmitted.
640
ACUS11 KWNS 031704
SWOMCD
SPC MCD 031703
SCZ000-GAZ000-031830-
Mesoscale Discussion 0491
NWS Storm Prediction Center Norman OK
1203 PM CDT Mon May 03 2021
Areas affected...north central Georgia into northern and central
South Carolina
Concerning...Tornado Watch 127...
Valid 031703Z - 031830Z
The severe weather threat for Tornado Watch 127 continues.
SUMMARY...Threat for isolated tornadoes will persist another couple
hours over north central Georgia. Severe threat is expected to
develop eastward into northern and central South Carolina this
afternoon where another WW will be needed soon.
DISCUSSION...Storms continue developing along several east-west
oriented boundaries across north central GA where the environment
remains favorable for occasional supercells with low-level
mesocyclones and isolated tornadoes. The atmosphere is destabilizing
from the southwest across central and north central GA into central
SC. Low-level hodographs will remain sufficient for supercells with
isolated tornadoes as the low-level jet continues to shift northeast
through northern GA and into western and central SC while the
atmospheres destabilize from the south and west.
..Dial/Grams.. 05/03/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CAE...GSP...FFC...
LAT...LON 34158467 34298266 34978087 33738126 32918405 33368500
33888517 34158467SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 3, 10:04 AM EDT | Mesoscale Discussion | SPC | Barrow, Butts, Carroll, Clayton, Cobb, Coweta and 15 more | 86 min |
| May 3, 10:29 AM EDT | Tornado Watch | SPC | Baldwin, Barrow, Bartow, Bibb, Butts, Carroll and 45 more | 5 hr |
| May 3, 11:20 AM EDT | Mesoscale Discussion | SPC | Clayton, DeKalb, Gwinnett, Rockdale | 55 min |
| May 3, 1:25 PM EDT | Tornado Watch | SPC | Burke, Columbia, Elbert, Lincoln, McDuffie, Richmond | 6 hr |
| May 3, 3:05 PM EDT | Mesoscale Discussion | SPC | Baldwin, Barrow, Bibb, Butts, Carroll, Chattahoochee and 36 more | 55 min |
| May 3, 3:23 PM EDT | Severe Thunderstorm Watch | SPC | Baldwin, Barrow, Bibb, Butts, Carroll, Chattahoochee and 55 more | 6 hr |
| May 3, 4:26 PM EDT | Mesoscale Discussion | SPC | Richmond | 94 min |
| May 3, 5:00 PM EDT | Mesoscale Discussion | SPC | Baldwin, Bibb, Butts, Calhoun, Carroll, Chattahoochee and 45 more | 90 min |
| May 3, 2:42 PM EDT | Mesoscale Discussion | SPC | Abbeville, Greenwood, Laurens, Newberry, Union | 63 min |
Nearby
Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in South Carolina, 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.