Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 480, NWS Atlanta, GA

August 21, 2011DeKalb County, Fulton County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Aug 21, 2011, 7:47 PM EDT for DeKalb County, Fulton County, Georgia. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 21, 2011, 7:47 PM EDT (23:47 UTC)
Expired
Aug 21, 2011, 8:13 PM EDT
In force
26 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon

Counties DeKalb County, GA, Fulton County, GA

The radar

The Atlanta radar (KFFC), 56 km from the middle of the area, began a volume at 23:50 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 11.8 hours before the alert went out and 54 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 2011-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 428 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 2011-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
428 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
1235 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
-9 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.

917 
WUUS52 KFFC 212347
SVRFFC
GAC089-121-220030-
/O.NEW.KFFC.SV.W.0480.110821T2347Z-110822T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
747 PM EDT SUN AUG 21 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  CENTRAL FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 830 PM EDT

* AT 742 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZED HAIL...AND
  DAMAGING WINDS UP TO 60 MPH.  THIS STORM WAS LOCATED NEAR
  BUCKHEAD...MOVING SOUTHEAST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MIDTOWN...ATLANTA...CHAMBLEE...DORAVILLE...GRANT PARK-ZOO
  ATLANTA...DRUID HILLS...DECATUR...TUCKER...PINE LAKE...AVONDALE
  ESTATES...STONE MOUNTAIN AND CLARKSTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

&&

LAT...LON 3383 8445 3385 8446 3388 8444 3391 8445
      3396 8439 3392 8426 3387 8420 3386 8416
      3379 8408 3364 8417 3365 8421 3380 8450
TIME...MOT...LOC 2347Z 296DEG 11KT 3386 8440

$$
1 follow-up statement
124 
WWUS52 KFFC 220013
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
813 PM EDT SUN AUG 21 2011

GAC089-121-220022-
/O.CAN.KFFC.SV.W.0480.000000T0000Z-110822T0030Z/
DEKALB GA-FULTON GA-
813 PM EDT SUN AUG 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL FULTON AND DEKALB
COUNTIES IS CANCELLED...

THE THUNDERSTORM HAS WEAKENED AND IS NO LONGER EXPECTED TO PRODUCE 
SEVERE WEATHER. HOWEVER...STRONG GUSTY WINDS UP TO 45 MPH...VERY 
HEAVY RAIN...AND OCCASIONAL LIGHTNING ARE STILL POSSIBLE WITH THIS 
STORM.

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL AFTER THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

LAT...LON 3383 8445 3385 8446 3388 8444 3391 8445
      3396 8439 3392 8426 3387 8420 3386 8416
      3379 8408 3364 8417 3365 8421 3380 8450
TIME...MOT...LOC 0012Z 296DEG 11KT 3383 8432

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 5:41 PM EDTSpecial Weather StatementFFCGordon, Murray, Pickens, Whitfield49 min
Aug 21, 6:10 PM EDTSpecial Weather StatementFFCDouglas35 min
Aug 21, 6:22 PM EDTSevere Thunderstorm WarningFFCDouglas, Fulton38 min
Aug 21, 6:40 PM EDTSpecial Weather StatementFFCCherokee, Pickens50 min
Aug 21, 6:52 PM EDTSpecial Weather StatementFFCCoweta23 min
Aug 21, 7:05 PM EDTSpecial Weather StatementFFCDouglas25 min
Aug 21, 7:22 PM EDTSpecial Weather StatementFFCDeKalb, Fulton38 min
Aug 21, 7:30 PM EDTSpecial Weather StatementFFCCherokee30 min
Aug 21, 7:36 PM EDTSpecial Weather StatementFFCDouglas39 min
Aug 21, 7:43 PM EDTSevere Thunderstorm WarningFFCForsyth, Fulton, Gwinnett33 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2011Every severe thunderstorm warning in 2011

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.