Alert archive / Georgia / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 568, NWS Atlanta, GA

August 12, 1999Sumter County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Aug 12, 1999, 4:58 PM EDT for Sumter County, Georgia. It was in force for 32 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 12, 1999, 4:58 PM EDT (20:58 UTC)
Expired
Aug 12, 1999, 5:30 PM EDT
In force
32 min
Issued by
NWS Atlanta, GA
Area
Whole counties

County Sumter County, GA

What was reported inside it

TimeReportWhereRemark
Aug 12, 5:20 PM EDTThunderstorm WindAmericus, GAThe Sumter county sheriff's office reported several trees down.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 9.0 hours before the alert went out and 183 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 1999-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1923 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 1999-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.1939Sfc1 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
1923 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1025 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KATL 122055 RRA
SVRATL
GAC261-122130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
458 PM EDT THU AUG 12 1999

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SUMTER COUNTY IN WEST CENTRAL GEORGIA

* UNTIL 530 PM EDT

* AT 456 PM EDT... A SEVERE THUNDERSTORM WAS INDICATED BY DOPPLER
  RADAR  6 MILES SOUTHWEST OF AMERICUS OR 3 MILES NORTHWEST OF
  SUMTER... MOVING WEST AT 5 MPH.

* THIS STORM WILL REMAIN OVER RURAL AREAS.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL AND DEADLY LIGHTNING. FOR YOUR PROTECTION MOVE TO
AN INTERIOR ROOM ON THE LOWEST FLOOR ZOF YOUR HOME OR BUSINESS. IF
YOU SEE DAMAGE OR LARGE HAIL...CALL THE NATIONAL WEATHER SERVICE
AT 770-486-1133 AT EXTENSION 2 0 4.

The office that day

Everything else NWS Atlanta, GA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 5:23 PM EDTSevere Thunderstorm WarningFFCTalbot, Taylor32 min
Aug 12, 5:55 PM EDTSevere Thunderstorm WarningFFCMarion, Talbot, Taylor35 min
Aug 12, 6:08 PM EDTSevere Thunderstorm WarningFFCSchley32 min
Aug 12, 6:18 PM EDTSevere Thunderstorm WarningFFCHarris, Meriwether32 min
Aug 12, 6:32 PM EDTSevere Thunderstorm WarningFFCMarion33 min

Nearby

Severe Thunderstorm Warnings in Georgia, 1999Every severe thunderstorm warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.