Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 189, NWS Atlanta, GA

April 21, 20116 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Apr 21, 2011, 3:08 AM EDT for 6 counties in Georgia. It was in force for 52 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
Apr 21, 2011, 3:08 AM EDT (07:08 UTC)
Expired
Apr 21, 2011, 4:00 AM EDT
In force
52 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon

Counties Cherokee County, GA, Dawson County, GA, DeKalb County, GA, Forsyth County, GA, Fulton County, GA, Gwinnett County, GA

The radar

The Atlanta radar (KFFC), 98 km from the middle of the area, began a volume at 07:11 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 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, 7.1 hours before the alert went out and 95 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.

181 
WUUS52 KFFC 210708
SVRFFC
GAC057-085-089-117-121-135-210800-
/O.NEW.KFFC.SV.W.0189.110421T0708Z-110421T0800Z/

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

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHEROKEE COUNTY IN NORTH CENTRAL GEORGIA
  SOUTHERN DAWSON COUNTY IN NORTH CENTRAL GEORGIA
  NORTHWESTERN DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  FORSYTH COUNTY IN NORTH CENTRAL GEORGIA
  NORTHEASTERN FULTON COUNTY IN NORTH CENTRAL GEORGIA
  GWINNETT COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 400 AM EDT

* AT 307 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 BALL GROUND TO ALPHARETTA TO
  CHAMBLEE...MOVING EAST AT 55 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MILTON...DORAVILLE...FREE HOME...NORCROSS...BERKELEY LAKE...JOHNS
  CREEK...DULUTH...LILBURN...CUMMING...SUWANEE...SUGAR HILL...
  BUFORD...LAWRENCEVILLE...REST HAVEN AND DACULA.

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 3442 8398 3428 8393 3427 8396 3420 8398
      3419 8405 3417 8406 3409 8386 3411 8382
      3400 8387 3393 8380 3391 8383 3385 8445
      3392 8444 3398 8437 3407 8442 3408 8449
      3440 8465 3437 8439 3438 8426 3441 8426
TIME...MOT...LOC 0708Z 264DEG 47KT 3430 8441 3408 8431
          3389 8431

$$
3 follow-up statements
165 
WWUS52 KFFC 210732
SVSFFC

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

GAC057-210741-
/O.CAN.KFFC.SV.W.0189.000000T0000Z-110421T0800Z/
CHEROKEE GA-
332 AM EDT THU APR 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR CHEROKEE COUNTY IS
CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS EXITED CHEROKEE 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 3442 8398 3428 8393 3427 8396 3420 8398
      3419 8405 3417 8406 3409 8386 3410 8382
      3400 8387 3393 8380 3391 8383 3385 8445
      3392 8444 3398 8437 3410 8442 3413 8436
      3419 8433 3419 8426 3441 8426
TIME...MOT...LOC 0731Z 264DEG 47KT 3433 8405 3411 8395
          3392 8395

$$

GAC085-089-117-121-135-210800-
/O.CON.KFFC.SV.W.0189.000000T0000Z-110421T0800Z/
DAWSON GA-DEKALB GA-FORSYTH GA-GWINNETT GA-FULTON GA-
332 AM EDT THU APR 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 AM EDT
FOR NORTHEASTERN FULTON...GWINNETT...FORSYTH...NORTHWESTERN DEKALB
AND SOUTHERN DAWSON COUNTIES...

AT 325 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 SILVER CITY TO SUGAR HILL TO
LAWRENCEVILLE...MOVING EAST AT 45 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
LUMPKIN...HOG MOUNTAIN...CHESTATEE...OSCARVILLE...DACULA...WAR HILL
PARK AND HARBIN.

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 3442 8398 3428 8393 3427 8396 3420 8398
      3419 8405 3417 8406 3409 8386 3410 8382
      3400 8387 3393 8380 3391 8383 3385 8445
      3392 8444 3398 8437 3410 8442 3413 8436
      3419 8433 3419 8426 3441 8426
TIME...MOT...LOC 0731Z 264DEG 47KT 3433 8405 3411 8395
          3392 8395

$$
998 
WWUS52 KFFC 210742
SVSFFC

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

GAC089-121-210751-
/O.CAN.KFFC.SV.W.0189.000000T0000Z-110421T0800Z/
DEKALB GA-FULTON GA-
342 AM EDT THU APR 21 2011

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

THE STORM THAT PROMPTED THE WARNING HAS EXITED FULTON AND DEKALB 
COUNTIES.

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 3442 8398 3428 8393 3427 8396 3420 8398
      3419 8405 3417 8406 3410 8383 3400 8387
      3393 8380 3391 8383 3387 8421 3393 8427
      3398 8426 3400 8423 3399 8420 3403 8417
      3405 8410 3411 8426 3441 8426
TIME...MOT...LOC 0741Z 264DEG 47KT 3434 8389 3412 8379
          3393 8379

$$

GAC085-117-135-210800-
/O.CON.KFFC.SV.W.0189.000000T0000Z-110421T0800Z/
DAWSON GA-FORSYTH GA-GWINNETT GA-
342 AM EDT THU APR 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 AM EDT
FOR GWINNETT...FORSYTH AND SOUTHERN DAWSON COUNTIES...

AT 339 AM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING QUARTER SIZED HAIL...AND DAMAGING WINDS UP TO 60 MPH.
THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM WAR HILL PARK
TO 8 MILES NORTHEAST OF HOG MOUNTAIN TO HARBIN...MOVING EAST AT 45 
MPH.  THESE STORMS HAVE WEAKENED AND WILL LIKELY CONTINUE TO DO SO.

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 3442 8398 3428 8393 3427 8396 3420 8398
      3419 8405 3417 8406 3410 8383 3400 8387
      3393 8380 3391 8383 3387 8421 3393 8427
      3398 8426 3400 8423 3399 8420 3403 8417
      3405 8410 3411 8426 3441 8426
TIME...MOT...LOC 0741Z 264DEG 47KT 3434 8389 3412 8379
          3393 8379

$$
884 
WWUS52 KFFC 210752
SVSFFC

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

GAC085-117-135-210801-
/O.EXP.KFFC.SV.W.0189.000000T0000Z-110421T0800Z/
DAWSON GA-FORSYTH GA-GWINNETT GA-
352 AM EDT THU APR 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR GWINNETT...FORSYTH AND 
SOUTHERN DAWSON COUNTIES WILL BE ALLOWED TO EXPIRE AT 400 AM EDT...

AT 349 AM EDT...A LINE OF STRONG THUNDERSTORMS WAS REPORTED. THESE 
STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 12 MILES EAST OF WAR 
HILL PARK TO 16 MILES EAST OF HOG MOUNTAIN TO 11 MILES EAST OF 
HARBIN...MOVING EAST AT 55 MPH.

THE STORMS THAT PROMPTED THE WARNING HAVE MOVED OUT OF THE WARNED 
AREA...THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE AT 4 AM.

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 3442 8398 3428 8393 3427 8396 3420 8398
      3419 8405 3417 8406 3410 8383 3400 8387
      3393 8380 3391 8383 3387 8421 3393 8427
      3398 8426 3400 8423 3399 8420 3403 8417
      3405 8410 3411 8426 3441 8426
TIME...MOT...LOC 0751Z 264DEG 47KT 3435 8373 3413 8363
          3394 8363

$$

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, 2:46 AM EDTSevere Thunderstorm WarningFFCCobb, Douglas, Fulton, Paulding44 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.