Alert archive / Georgia / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 493, NWS Atlanta, GA

July 21, 1999Clayton County, Henry County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Jul 21, 1999, 5:25 PM EDT for Clayton County, Henry County, Georgia. It was in force for 35 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
Jul 21, 1999, 5:25 PM EDT (21:25 UTC)
Expired
Jul 21, 1999, 6:00 PM EDT
In force
35 min
Issued by
NWS Atlanta, GA
Area
Whole counties

Counties Clayton County, GA, Henry County, GA

What was reported inside it

TimeReportWhereRemark
Jul 21, 5:53 PM EDTThunderstorm WindStockbridge, GAHenry county 911 reported power lines blown 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 9.4 hours before the alert went out and 27 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, Peachtre/Fal Fld, GA at 12:00Z on 1999-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 316 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, Peachtre/Fal Fld, GA at 12:00Z on 1999-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
316 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1101 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
-13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 3:16 PM EDTSevere Thunderstorm WarningFFCHall34 min
Jul 21, 4:14 PM EDTSevere Thunderstorm WarningFFCDawson, Lumpkin36 min
Jul 21, 6:05 PM EDTSevere Thunderstorm WarningFFCCoweta, Fulton35 min
Jul 21, 6:15 PM EDTSevere Thunderstorm WarningFFCFayette35 min
Jul 21, 6:24 PM EDTSevere Thunderstorm WarningFFCCobb36 min
Jul 21, 6:42 PM EDTSevere Thunderstorm WarningFFCCoweta, Spalding33 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.