Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 188, NWS Atlanta, GA

April 21, 20114 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Apr 21, 2011, 2:46 AM EDT for 4 counties in Georgia. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 21, 2011, 2:46 AM EDT (06:46 UTC)
Expired
Apr 21, 2011, 3:30 AM EDT
In force
44 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon

Counties Cobb County, GA, Douglas County, GA, Fulton County, GA, Paulding County, GA

The radar

The Atlanta radar (KFFC), 50 km from the middle of the area, began a volume at 06:48 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 was reported inside it

TimeReportWhereRemark
Apr 21, 2:53 AM EDTTSTM WND DMG4 S Marietta, GAA FEW TREES DOWN ON PAT MELL ROAD. TREE FELL ON CAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 21, 2:32 AM EDTSevere Thunderstorm WatchSPC2 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 6.8 hours before the alert went out and 50 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 00:00Z on 2011-04-21Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 00:00Z on 2011-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
-171 J/kg
Mixed-layer LCL
1406 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
108 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.

096 
WUUS52 KFFC 210646
SVRFFC
GAC067-097-121-223-210730-
/O.NEW.KFFC.SV.W.0188.110421T0646Z-110421T0730Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
246 AM EDT THU APR 21 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  COBB COUNTY IN NORTH CENTRAL GEORGIA
  DOUGLAS COUNTY IN NORTH CENTRAL GEORGIA
  WESTERN FULTON COUNTY IN NORTH CENTRAL GEORGIA
  PAULDING COUNTY IN NORTHWEST GEORGIA

* UNTIL 330 AM EDT

* AT 244 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZED
  HAIL...AND DAMAGING WINDS UP TO 60 MPH.  THESE STORMS WERE LOCATED
  ALONG A LINE EXTENDING FROM ACWORTH TO POWDER SPRINGS TO 12 MILES
  WEST OF FAIRBURN...MOVING EAST AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  KENNESAW...MARIETTA...SMYRNA...UNION CITY...MOUNTAIN PARK...SANDY
  SPRINGS...BUCKHEAD...EAST POINT...COLLEGE PARK...MIDTOWN...
  ROSWELL...ATLANTA...HAPEVILLE AND GRANT PARK-ZOO ATLANTA.

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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT
THURSDAY MORNING FOR NORTHERN GEORGIA.

&&

LAT...LON 3407 8491 3407 8442 3408 8442 3408 8436
      3397 8434 3365 8435 3364 8446 3355 8446
      3353 8458 3353 8472 3366 8469 3363 8490
      3378 8490 3384 8493
TIME...MOT...LOC 0646Z 263DEG 36KT 3409 8466 3386 8461
          3352 8475

$$
1 follow-up statement
726 
WWUS52 KFFC 210713
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
313 AM EDT THU APR 21 2011

GAC097-223-210721-
/O.CAN.KFFC.SV.W.0188.000000T0000Z-110421T0730Z/
PAULDING GA-DOUGLAS GA-
313 AM EDT THU APR 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR DOUGLAS AND EASTERN PAULDING
COUNTIES IS CANCELLED...

THE LINE OF THUNDERSTORMS THAT PROMPTED THE WARNING HAS MOVED OUT OF 
THE COUNTY.

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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT
THURSDAY MORNING FOR NORTHERN GEORGIA.

LAT...LON 3407 8474 3408 8436 3397 8434 3365 8436
      3364 8446 3355 8446 3353 8458 3353 8472
      3365 8469 3366 8466 3368 8465 3374 8458
      3380 8462 3381 8473
TIME...MOT...LOC 0711Z 263DEG 36KT 3412 8436 3389 8431
          3355 8445

$$

GAC067-121-210730-
/O.CON.KFFC.SV.W.0188.000000T0000Z-110421T0730Z/
COBB GA-FULTON GA-
313 AM EDT THU APR 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 AM EDT
FOR WESTERN FULTON AND COBB COUNTIES...

AT 307 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER
SIZED HAIL...AND DAMAGING WINDS UP TO 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM SWEAT MOUNTAIN TO CHASTAIN
MEMORIAL PARK TO UNION CITY...MOVING EAST AT 40 MPH.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT
THURSDAY MORNING FOR NORTHERN GEORGIA.

&&

LAT...LON 3407 8474 3408 8436 3397 8434 3365 8436
      3364 8446 3355 8446 3353 8458 3353 8472
      3365 8469 3366 8466 3368 8465 3374 8458
      3380 8462 3381 8473
TIME...MOT...LOC 0711Z 263DEG 36KT 3412 8436 3389 8431
          3355 8445

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 1:54 AM EDTSevere Thunderstorm WarningFFCCarroll, Haralson51 min
Apr 21, 2:06 AM EDTSevere Thunderstorm WarningFFCBartow, Floyd, Polk39 min
Apr 21, 2:27 AM EDTSevere Thunderstorm WarningFFCCarroll, Coweta, Douglas, Fulton, Heard48 min
Apr 21, 3:08 AM EDTSevere Thunderstorm WarningFFCCherokee, Dawson, DeKalb, Forsyth, Fulton, Gwinnett52 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.