Alert archive / Georgia / Mesoscale Discussions in 2023
Mesoscale Discussion 1021
The Storm Prediction Center issued this mesoscale discussion at Jun 13, 2023, 6:12 PM EDT for 13 counties in Florida; 24 counties in Georgia. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- Jun 13, 2023, 6:12 PM EDT (22:12 UTC)
- Expired
- Jun 13, 2023, 7:45 PM EDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 284
All 37 counties
Baker County, FL, Bradford County, FL, Clay County, FL, Columbia County, FL, Duval County, FL, Gilchrist County, FL, Hamilton County, FL, Lafayette County, FL, Madison County, FL, Nassau County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Berrien County, GA, Brantley County, GA, Brooks County, GA, Bryan County, GA, Camden County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Echols County, GA, Glynn County, GA, Jeff Davis County, GA, Lanier County, GA, Liberty County, GA, Long County, GA, Lowndes County, GA, McIntosh County, GA, Pierce County, GA, Tattnall County, GA, Ware County, GA, Wayne County, GA
The radar
The Moody AFB radar (KVAX), 23 km from the middle of the area, began a volume at 22:15 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
Jacksonville, FL (KJAX), launched 12:00Z, 10.2 hours before the alert went out and 110 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
- 1348 J/kg
- Mixed-layer CIN
- -65 J/kg
- Mixed-layer LCL
- 736 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 166 m²/s²
- 0-3 km storm-relative helicity
- 175 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 5.1
The text
As transmitted.
002
ACUS11 KWNS 132212
SWOMCD
SPC MCD 132212
SCZ000-GAZ000-FLZ000-132345-
Mesoscale Discussion 1021
NWS Storm Prediction Center Norman OK
0512 PM CDT Tue Jun 13 2023
Areas affected...southeast Georgia and northern Florida
Concerning...Severe Thunderstorm Watch 284...
Valid 132212Z - 132345Z
The severe weather threat for Severe Thunderstorm Watch 284
continues.
SUMMARY...A damaging wind threat across southeast Georgia into
northern Florida will persist for another 1 to 2 hours.
DISCUSSION...A cluster of storms across southern Georgia has had
several reports of both measured severe wind gusts and damaging wind
gusts. The environment downstream of these storms remains very
unstable with MLCAPE around 2000 to 2500 J/kg. However, these storms
have outrun the better mid-level flow with only 20 to 25 knots of
effective shear per JAX VWP. As a result, storm organization and
hail potential remains marginal. However, the linear segment should
persist east into the greater instability with a continued threat
for damaging wind gusts to the Atlantic coast.
Storms developing across northern Florida have been mostly
unorganized, likely due to the aforementioned weak effective shear.
However, water loading amid PWAT values near 2 inches could support
some wet microbursts.
..Bentley.. 06/13/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CHS...JAX...FFC...TAE...
LAT...LON 30078403 30708375 31008341 31568316 31898293 32108262
32068081 31568096 30608104 29998135 29588320 29628394
30018410 30078403SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 13, 12:01 PM EDT | Mesoscale Discussion | SPC | Gadsden, Holmes, Jackson, Leon, Santa Rosa, Washington | 2 hr |
| Jun 13, 1:30 PM EDT | Severe Thunderstorm Watch | SPC | Bay, Calhoun, Escambia, Gadsden, Holmes, Jackson and 9 more | 7 hr |
| Jun 13, 3:42 PM EDT | Mesoscale Discussion | SPC | Baker, Columbia, Duval, Gadsden, Hamilton, Holmes and 6 more | 2 hr |
| Jun 13, 4:03 PM EDT | Severe Thunderstorm Watch | SPC | Baker, Columbia, Duval, Hamilton, Nassau, Suwannee | 5 hr |
| Jun 13, 6:26 PM EDT | Mesoscale Discussion | SPC | Bay, Calhoun, Holmes, Jackson, Liberty, Okaloosa and 2 more | 64 min |
Nearby
Mesoscale Discussions in Georgia, 2023Mesoscale Discussions in Florida, 2023Every mesoscale discussion in 2023
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.