Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 495
The Storm Prediction Center issued this mesoscale discussion at May 3, 2021, 3:05 PM EDT for 42 counties in Georgia. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- May 3, 2021, 3:05 PM EDT (19:05 UTC)
- Expired
- May 3, 2021, 4:00 PM EDT
- In force
- 55 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 127
All 42 counties
Baldwin County, GA, Barrow County, GA, Bibb County, GA, Butts County, GA, Carroll County, GA, Chattahoochee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, DeKalb County, GA, Douglas County, GA, Fayette County, GA, Fulton County, GA, Greene County, GA, Gwinnett County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Jones County, GA, Lamar County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Muscogee County, GA, Newton County, GA, Oconee County, GA, Paulding County, GA, Peach County, GA, Pike County, GA, Putnam County, GA, Rockdale County, GA, Spalding County, GA, Talbot County, GA, Taylor County, GA, Troup County, GA, Upson County, GA, Walton County, GA
The radar
The Atlanta radar (KFFC), 23 km from the middle of the area, began a volume at 19:10 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, 7.1 hours before the alert went out and 17 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.
452
ACUS11 KWNS 031906
SWOMCD
SPC MCD 031905
GAZ000-ALZ000-032000-
Mesoscale Discussion 0495
NWS Storm Prediction Center Norman OK
0205 PM CDT Mon May 03 2021
Areas affected...central through north central Georgia
Concerning...Tornado Watch 127...
Valid 031905Z - 032000Z
The severe weather threat for Tornado Watch 127 continues.
SUMMARY...Tornado watch 127 is scheduled to expire at 20Z. Overall
tornado threat is not as high as earlier today, and greatest
short-term threat exists across the eastern third of WW 127.
Expected tendency is for the tornado threat to gradually decrease
with time, but a few storms could still produce locally strong wind
gusts and possibly some hail the remainder of the afternoon.
Depending on trends, WW 127 might be replaced by a severe
thunderstorm watch within the next hour.
DISCUSSION...Low-level winds have been gradually veering during the
afternoon as the primary low-level jet shifts northeast through the
Carolinas and into the Middle Atlantic. This has resulted in a
reduction in size of 0-1 km hodographs and a decrease in overall
tornado threat over most of north Georgia. However, the boundary
layer is destabilizing, and widely scattered storms will continue
developing within a moderately unstable environment where 30-40 kt
effective bulk shear remains sufficient for some storms to develop
mid-level updraft rotation. Isolated downbursts and hail should
become the main threats with any stronger storms developing beyond
20Z.
..Dial.. 05/03/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FFC...BMX...
LAT...LON 34078514 34178336 33708297 32728339 32298435 32378498
33628522 34078514SPC 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, 1:03 PM EDT | Mesoscale Discussion | SPC | Barrow, Butts, Clarke, Clayton, Cobb, Columbia and 30 more | 87 min |
| May 3, 1:25 PM EDT | Tornado Watch | SPC | Burke, Columbia, Elbert, Lincoln, McDuffie, Richmond | 6 hr |
| 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 |
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.