Alert archive / Georgia / Mesoscale Discussions in 2021
Mesoscale Discussion 1029
The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2021, 5:00 AM CDT for Houston County, Alabama; 15 counties in Florida; 62 counties in Georgia. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2021, 5:00 AM CDT (10:00 UTC)
- Expired
- Jun 20, 2021, 7:00 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 292
All 78 counties
Houston County, AL, Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Hamilton County, FL, Jackson County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Wakulla County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Baker County, GA, Ben Hill County, GA, Berrien County, GA, Bleckley County, GA, Brantley County, GA, Brooks County, GA, Calhoun County, GA, Candler County, GA, Charlton County, GA, Clay County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Cook County, GA, Crisp County, GA, Decatur County, GA, Dodge County, GA, Dooly County, GA, Dougherty County, GA, Early County, GA, Echols County, GA, Emanuel County, GA, Grady County, GA, Houston County, GA, Irwin County, GA, Jeff Davis County, GA, Johnson County, GA, Lanier County, GA, Laurens County, GA, Lee County, GA, Long County, GA, Lowndes County, GA, Macon County, GA, Miller County, GA, Mitchell County, GA, Montgomery County, GA, Peach County, GA, Pierce County, GA, Pulaski County, GA, Randolph County, GA, Schley County, GA, Seminole County, GA, Sumter County, GA, Tattnall County, GA, Telfair County, GA, Terrell County, GA, Thomas County, GA, Tift County, GA, Toombs County, GA, Treutlen County, GA, Turner County, GA, Twiggs County, GA, Ware County, GA, Wayne County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Wilkinson County, GA, Worth County, GA
The radar
The Tallahassee radar (KTLH), 76 km from the middle of the area, began a volume at 09:59 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
Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 10.0 hours before the alert went out and 75 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
- 1506 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 764 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 152 m²/s²
- 0-3 km storm-relative helicity
- 223 m²/s²
- Significant tornado parameter
- 0.9
- Supercell composite
- 7.3
The text
As transmitted.
659
ACUS11 KWNS 201000
SWOMCD
SPC MCD 201000
GAZ000-FLZ000-ALZ000-201200-
Mesoscale Discussion 1029
NWS Storm Prediction Center Norman OK
0500 AM CDT Sun Jun 20 2021
Areas affected...Florida Panhandle...Far Southeast
Alabama...Southwest Georgia
Concerning...Tornado Watch 292...
Valid 201000Z - 201200Z
The severe weather threat for Tornado Watch 292 continues.
SUMMARY...A tornado threat is likely to continue for a couple more
hours across parts of the Florida Panhandle, far southeast Alabama
and southwest Georgia. Another tornado watch may be needed beyond
the 7 am EDT expiration of tornado watch 292.
DISCUSSION...The latest radar imagery shows a couple of bands of
thunderstorms associated with the remnants of Claudette. The first
is located from far southeast Alabama into southwest Georgia, with
the second smaller band located across the Florida Panhandle.
Surface dewpoints in the lower to mid 70s F are contributing to
moderate instability, with the RAP estimating MLCAPE in the 1000 to
2000 J/Kg range. In addition, the Tallahassee WSR-88D VWP has a
strong wind field in the low to mid-levels. 0-1 km shear is measured
near 25 kt with 0-3 km storm-relative helicities around 200 m2/s2.
Low-level shear is likely even stronger in southwest Georgia where
the southern edge of a jet near 850 mb is located. Due to the strong
low-level shear, cells embedded in these two bands will have a
chance to be supercellular and produce tornadoes. Although tornadoes
may be brief, the threat should at least continue for a couple more
hours.
..Broyles/Edwards.. 06/20/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CHS...JAX...FFC...TAE...
LAT...LON 31618517 32488415 32978319 32548213 31638160 30808190
30008299 29698444 29608498 29658532 30048576 30698556
31448522 31618517SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 19, 7:00 PM CDT | Tornado Watch | SPC | Barbour, Coffee, Dale, Geneva, Henry, Houston and 2 more | 13 hr |
| Jun 19, 11:58 PM CDT | Mesoscale Discussion | SPC | Dale, Geneva, Henry, Houston | 2 hr |
| Jun 20, 7:40 AM CDT | Mesoscale Discussion | SPC | Baker, Columbia, Duval, Hamilton, Madison, Nassau and 1 more | 3 hr |
| Jun 20, 10:01 AM CDT | Mesoscale Discussion | SPC | Alachua, Bradford, Clay | 119 min |
Nearby
Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in Florida, 2021Mesoscale Discussions in Alabama, 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.