Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 1810
The Storm Prediction Center issued this mesoscale discussion at Oct 8, 2021, 1:56 AM EDT for 12 counties in Georgia. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Oct 8, 2021, 1:56 AM EDT (05:56 UTC)
- Expired
- Oct 8, 2021, 3:30 AM EDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Bleckley County, GA, Crisp County, GA, Dodge County, GA, Dooly County, GA, Laurens County, GA, Montgomery County, GA, Pulaski County, GA, Sumter County, GA, Toombs County, GA, Treutlen County, GA, Wheeler County, GA, Wilcox County, GA
The radar
The Robins AFB radar (KJGX), 52 km from the middle of the area, began a volume at 05:59 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 nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 5.9 hours before the alert went out and 171 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
- 785 J/kg
- Mixed-layer CIN
- -11 J/kg
- Mixed-layer LCL
- 833 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 63 m²/s²
- 0-3 km storm-relative helicity
- 163 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.4
The text
As transmitted.
894
ACUS11 KWNS 080557
SWOMCD
SPC MCD 080556
GAZ000-080730-
Mesoscale Discussion 1810
NWS Storm Prediction Center Norman OK
1256 AM CDT Fri Oct 08 2021
Areas affected...Portions of central GA
Concerning...Severe potential...Watch unlikely
Valid 080556Z - 080730Z
Probability of Watch Issuance...5 percent
SUMMARY...A very isolated severe threat may exist with storms across
central Georgia early this morning. Watch issuance is not expected.
DISCUSSION...A marginal supercell has persisted early this morning
across central GA per recent radar imagery from KJGX. The
environment downstream of this storm appears only modestly favorable
for continued storm organization over the next hour or two, with
20-30 kt of deep-layer shear and weak instability present per latest
mesoanalysis estimates. Even so, this storm has shown recent signs
of broad, weak low/mid-level rotation. The VWP from KJGX indicates
around 15 kt of 0-1-km shear exists, with slightly over 100 m2/s2 of
0-1-km SRH also present. It remains unclear whether any additional,
marginal supercells will develop with the convection trailing the
leading storm given the weak large-scale forcing, and whether they
would be able to sustain themselves for a prolonged period of time
given the generally weak low-level winds present per the KJGX VWP.
The leading, marginal supercell will probably have a tendency to
weaken as it moves slowly eastward across central GA over the next
couple of hours, as the boundary-layer instability gradually
decreases with eastward extent while convective inhibition
increases. Any severe hail/wind or perhaps brief tornado threat
associated with this convection in the short term will likely remain
very isolated, and watch issuance is not expected.
..Gleason/Edwards.. 10/08/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CHS...FFC...
LAT...LON 32018446 32328374 32598352 32678291 32618250 32308218
32048232 31938281 31898336 31938401 32018446Nearby
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.