Alert archive / Georgia / Tornado Watches in 2020

Tornado Watch 448

August 24, 2020Houston County, Alabama; 9 counties in Florida; 15 counties in Georgia

The Storm Prediction Center issued this tornado watch at Aug 24, 2020, 3:39 PM CDT for Houston County, Alabama; 9 counties in Florida; 15 counties in Georgia. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Aug 24, 2020, 3:39 PM CDT (20:39 UTC)
Expired: Aug 25, 2020, 12:00 AM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Strongest gust expected: 60 kt

All 25 counties

Houston County, AL, Bay County, FL, Calhoun County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Berrien County, GA, Calhoun County, GA, Colquitt County, GA, Cook County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Grady 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), 70 km from the middle of the area, began a volume at 20:38 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: 40%
One or more EF2 to EF5 tornadoes: 10%
Ten or more severe wind reports: 5%
One or more gusts of 65 knots or more: 5%
Ten or more severe hail reports: 5%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 20%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Aug 24, 4:31 PM CDT	Flash Flood Warning	TAE	Bay, Holmes, Jackson, Washington	3 hr
Aug 24, 6:19 PM CDT	Severe Thunderstorm Warning	TAE	Berrien, Brooks, Cook, Lanier, Lowndes	26 min
Aug 24, 7:10 PM CDT	Tornado Warning	TAE	Jackson	35 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, 8.7 hours before the alert went out and 98 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 552 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 938 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 88 m²/s²
0-3 km storm-relative helicity: 82 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

As transmitted.

757 
WWUS20 KWNS 242036
SEL8  
SPC WW 242036
ALZ000-FLZ000-GAZ000-CWZ000-250400-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 448
NWS Storm Prediction Center Norman OK
440 PM EDT Mon Aug 24 2020

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Far Southeast Alabama
  Florida Panhandle
  Southwest Georgia
  Coastal Waters

* Effective this Monday afternoon from 440 PM until Midnight EDT.

* Primary threats include...
  A couple tornadoes possible

SUMMARY...A moist air mass and moderately strong low-level shear
will conducive for transient supercells capable of a tornado late
this afternoon and evening.

The tornado watch area is approximately along and 45 statute miles
north and south of a line from 45 miles west northwest of Panama
City FL to 30 miles north of Valdosta GA. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 0 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 14020.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 24, 10:51 AM CDT	Mesoscale Discussion	SPC	Baldwin, Mobile	84 min
Aug 24, 2:40 PM CDT	Mesoscale Discussion	SPC	Baldwin, Geneva, Henry, Houston	3 hr
Aug 24, 1:46 AM CDT	Mesoscale Discussion	SPC	Bay, Calhoun, Franklin, Gulf, Liberty, Wakulla	2 hr

Nearby

Tornado Watches in Georgia, 2020 Tornado Watches in Florida, 2020 Tornado Watches in Alabama, 2020 Every tornado watch in 2020

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.