Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 487
The Storm Prediction Center issued this mesoscale discussion at May 3, 2021, 10:04 AM EDT for 21 counties in Georgia. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- May 3, 2021, 10:04 AM EDT (14:04 UTC)
- Expired
- May 3, 2021, 11:30 AM EDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 21 counties
Barrow County, GA, Butts County, GA, Carroll County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, DeKalb County, GA, Douglas County, GA, Fayette County, GA, Forsyth County, GA, Fulton County, GA, Gwinnett County, GA, Henry County, GA, Jackson County, GA, Meriwether County, GA, Newton County, GA, Oconee County, GA, Pike County, GA, Rockdale County, GA, Spalding County, GA, Walton County, GA
The radar
The Atlanta radar (KFFC), 44 km from the middle of the area, began a volume at 14:05 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, 2.1 hours before the alert went out and 41 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.
073
ACUS11 KWNS 031404
SWOMCD
SPC MCD 031404
GAZ000-031530-
Mesoscale Discussion 0487
NWS Storm Prediction Center Norman OK
0904 AM CDT Mon May 03 2021
Areas affected...northern and central Georgia
Concerning...Severe potential...Watch possible
Valid 031404Z - 031530Z
Probability of Watch Issuance...60 percent
SUMMARY...Storms may undergo some intensification through the
morning and become capable of producing damaging wind and isolated
tornadoes. Trends are being monitored for a possible WW.
DISCUSSION...Late this morning storms continue developing within
corridor of ascent along a warm conveyor belt associated with 40-50
kt southwesterly low-level jet. The atmosphere remains marginally to
moderately unstable with 1000-1500 J/kg MLCAPE. Dewpoints rising
into the upper 60s and a modest amount of heating will result in
sufficient instability for surface based storms where low level
hodographs and deep shear are favorable for supercells with
low-level mesocyclones.
..Dial/Grams.. 05/03/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FFC...
LAT...LON 33758513 34278415 34208339 33808338 33218402 32888490
33758513SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| 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, 3:05 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 |
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.