Alert archive / Georgia / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 168

May 12, 20215 counties in Alabama; 15 counties in Florida; 19 counties in Georgia

The Storm Prediction Center issued this severe thunderstorm watch at May 12, 2021, 7:14 AM CDT for 5 counties in Alabama; 15 counties in Florida; 19 counties in Georgia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 12, 2021, 7:14 AM CDT (12:14 UTC)
Expired
May 12, 2021, 1:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
55 kt
All 39 counties

Coffee County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Jefferson County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Berrien County, GA, Brooks County, GA, Calhoun County, GA, Clay County, GA, Colquitt County, GA, Cook County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Grady County, GA, Lanier County, GA, Lowndes County, GA, Miller County, GA, Mitchell County, GA, Seminole County, GA, Thomas County, GA, Tift County, GA, Worth County, GA

The radar

The Ft Rucker radar (KEOX), 81 km from the middle of the area, began a volume at 12:16 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 12, 7:21 AM CDTSevere Thunderstorm WarningTAEGeneva54 min
May 12, 7:45 AM CDTSevere Thunderstorm WarningTAEWalton30 min
May 12, 10:06 AM CDTSevere Thunderstorm WarningTAEBaker, Brooks, Colquitt, Dougherty, Grady, Mitchell and 2 more69 min
May 12, 10:47 AM CDTSevere Thunderstorm WarningTAEBerrien, Brooks, Colquitt, Cook, Irwin, Lanier and 2 more48 min
May 12, 11:27 AM CDTSevere Thunderstorm WarningTAELeon, Liberty, Wakulla48 min
May 12, 12:07 PM CDTSevere Thunderstorm WarningTAEFranklin, Liberty, Wakulla38 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 0.2 hours before the alert went out and 87 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.

Skew-T log-pSkew-T log-p diagram, Tallahassee Rgnl, FL at 12:00Z on 2021-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 263 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2021-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
263 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
1066 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

627 
WWUS20 KWNS 121211
SEL8  
SPC WW 121211
ALZ000-FLZ000-GAZ000-CWZ000-121800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 168
NWS Storm Prediction Center Norman OK
815 AM EDT Wed May 12 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Southeast Alabama
  Northern Florida
  Southwest Georgia
  Coastal Waters

* Effective this Wednesday morning and afternoon from 815 AM
  until 200 PM EDT.

* Primary threats include...
  Scattered damaging wind gusts to 65 mph possible

SUMMARY...A well-organized cluster of storms will continue eastward
today across southeast Alabama and the Florida Panhandle toward
southern Georgia and additional parts of northern Florida, with
additional development possible later today near a
southward-advancing cold front. Isolated damaging winds are expected
to be the most common hazard.

The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 50 miles northwest of
Panama City FL to 20 miles south of Valdosta GA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
27035.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 12, 6:43 AM CDTMesoscale DiscussionSPCGeneva, Houston2 hr
May 12, 9:17 AM CDTMesoscale DiscussionSPCHenry, Houston118 min
May 12, 11:30 AM CDTMesoscale DiscussionSPCBaker, Bay, Bradford, Calhoun, Clay, Columbia and 16 more2 hr

Nearby

Severe Thunderstorm Watches in Georgia, 2021Severe Thunderstorm Watches in Florida, 2021Severe Thunderstorm Watches in Alabama, 2021Every severe thunderstorm watch 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.