Alert archive / Georgia / Tornado Warnings in 2011

Tornado Warning 20, NWS Atlanta, GA

April 15, 2011Cobb County, DeKalb County, Fulton County, Georgia

NWS Atlanta, GA issued this tornado warning at Apr 15, 2011, 8:02 PM EDT for Cobb County, DeKalb County, Fulton County, Georgia. It was in force for 43 min. 5 reports 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 15, 2011, 8:02 PM EDT (00:02 UTC)
Expired
Apr 15, 2011, 8:45 PM EDT
In force
43 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon

Counties Cobb County, GA, DeKalb County, GA, Fulton County, GA

The radar

The Atlanta radar (KFFC), 76 km from the middle of the area, began a volume at 00:03 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 15, 8:05 PM EDTHAIL 1.752 Ssw Sandy Springs, GAAT JOHNSON FERRY RD. NEAR FULTON-COBB COUNTY LINE.
Apr 15, 8:08 PM EDTTSTM WND DMGSandy Springs, GAFULTON COUNTY EMA RELAYED A REPORT OF TREE DOWN ACROSS THE NORTHERN AND CENTRAL PARTS OF THE COUNTY. ALSO REPORTS THAT A HOUSE HAS COLLAPSED IN THE SANDY SPRINGS AREA.
Apr 15, 8:14 PM EDTHAIL 11 S Sandy Springs, GANEAR RIVERWOOD HIGH SCHOOL
Apr 15, 8:18 PM EDTHAIL 0.51 N Dunwoody, GA
Apr 15, 8:45 PM EDTHAIL 18 E Marietta, GA

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 15, 5:46 PM EDTTornado WatchSPC3 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.0 hours before the alert went out and 73 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 2011-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 406 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 00:00Z on 2011-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 373 square meters per square second.19395878Sfc1 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
406 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
1138 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
373 m²/s²
0-3 km storm-relative helicity
566 m²/s²
Significant tornado parameter
1.3
Supercell composite
11.3

Open this sounding in Storm Lab

The text

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

251 
WFUS52 KFFC 160002
TORFFC
GAC067-089-121-160045-
/O.NEW.KFFC.TO.W.0020.110416T0002Z-110416T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
802 PM EDT FRI APR 15 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN COBB COUNTY IN NORTH CENTRAL GEORGIA
  NORTHERN DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  NORTHEASTERN FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 845 PM EDT

* AT 800 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SANDY
  SPRINGS...MOVING EAST AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  BUCKHEAD...ROSWELL...DUNWOODY...CHAMBLEE...ALPHARETTA...
  DORAVILLE...TUCKER AND JOHNS CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO A
BASEMENT OR INTERIOR ROOM ON THE GROUND FLOOR. STAY AWAY FROM
WINDOWS. IF DRIVING...DO NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

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 TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT SATURDAY MORNING
FOR NORTHERN GEORGIA.

&&

LAT...LON 3411 8426 3409 8420 3403 8416 3402 8417
      3399 8418 3400 8423 3398 8426 3393 8427
      3387 8420 3384 8415 3382 8453 3400 8454
      3415 8426
TIME...MOT...LOC 0003Z 267DEG 36KT 3391 8440

$$
2 follow-up statements
087 
WWUS52 KFFC 160022
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
822 PM EDT FRI APR 15 2011

GAC067-160031-
/O.CAN.KFFC.TO.W.0020.000000T0000Z-110416T0045Z/
COBB GA-
822 PM EDT FRI APR 15 2011

...THE TORNADO WARNING FOR EASTERN COBB COUNTY IS CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS MOVED EAST OF COBB 
COUNTY...THUS...THE TORNADO WARNING HAS BEEN CANCELED FOR COBB 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 TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT SATURDAY MORNING
FOR NORTHERN GEORGIA.

LAT...LON 3410 8425 3408 8419 3403 8416 3399 8418
      3400 8425 3396 8428 3393 8427 3385 8417
      3388 8436 3393 8443 3398 8437 3406 8442
      3414 8427
TIME...MOT...LOC 0021Z 267DEG 36KT 3392 8418

$$

GAC089-121-160045-
/O.CON.KFFC.TO.W.0020.000000T0000Z-110416T0045Z/
DEKALB GA-FULTON GA-
822 PM EDT FRI APR 15 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 PM EDT FOR
NORTHEASTERN FULTON AND NORTHWESTERN DEKALB COUNTIES...

AT 817 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A STRONG STORM WITH SOME ROTATION LOCATED NEAR 
DORAVILLE...MOVING EAST AT 40 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO JOHNS
CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING GOLF 
BALL SIZED HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

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 TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT SATURDAY MORNING
FOR NORTHERN GEORGIA.

&&

LAT...LON 3410 8425 3408 8419 3403 8416 3399 8418
      3400 8425 3396 8428 3393 8427 3385 8417
      3388 8436 3393 8443 3398 8437 3406 8442
      3414 8427
TIME...MOT...LOC 0021Z 267DEG 36KT 3392 8418

$$
614 
WWUS52 KFFC 160035
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
835 PM EDT FRI APR 15 2011

GAC089-160044-
/O.CAN.KFFC.TO.W.0020.000000T0000Z-110416T0045Z/
DEKALB GA-
835 PM EDT FRI APR 15 2011

...THE TORNADO WARNING FOR NORTHWESTERN DEKALB COUNTY IS CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS MOVED OUT OF DEKALB 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 TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT SATURDAY MORNING
FOR NORTHERN GEORGIA.

LAT...LON 3410 8425 3408 8419 3403 8416 3402 8417
      3399 8418 3400 8423 3400 8425 3397 8427
      3402 8431 3414 8427
TIME...MOT...LOC 0034Z 267DEG 36KT 3393 8402

$$

GAC121-160045-
/O.CON.KFFC.TO.W.0020.000000T0000Z-110416T0045Z/
FULTON GA-
835 PM EDT FRI APR 15 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 PM EDT FOR
NORTHEASTERN FULTON COUNTY...

AT 833 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE STRONG STORM WITH SOME ROTATION LOCATED 11 MILES SOUTHEAST 
OF JOHNS CREEK...MOVING EAST AT 40 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM IS CAPABLE OF PRODUCING GOLF BALL SIZED HAIL AND 
DESTRUCTIVE STRAIGHT LINE WINDS.

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 TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT SATURDAY MORNING
FOR NORTHERN GEORGIA.

&&

LAT...LON 3410 8425 3408 8419 3403 8416 3402 8417
      3399 8418 3400 8423 3400 8425 3397 8427
      3402 8431 3414 8427
TIME...MOT...LOC 0034Z 267DEG 36KT 3393 8402

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 15, 8:12 PM EDTSevere Thunderstorm WarningFFCLamar, Meriwether, Pike, Talbot, Upson48 min
Apr 15, 8:19 PM EDTSevere Thunderstorm WarningFFCBarrow, Gwinnett41 min
Apr 15, 8:28 PM EDTSevere Thunderstorm WarningFFCForsyth, Hall47 min
Apr 15, 8:45 PM EDTSevere Thunderstorm WarningFFCCobb, Douglas, Paulding45 min
Apr 15, 8:56 PM EDTSevere Thunderstorm WarningFFCButts, Lamar, Monroe, Pike, Upson49 min
Apr 15, 9:18 PM EDTSevere Thunderstorm WarningFFCButts, Jasper, Jones, Monroe42 min
Apr 15, 9:19 PM EDTSevere Thunderstorm WarningFFCDeKalb, Forsyth, Fulton, Gwinnett41 min
Apr 15, 10:44 PM EDTRiver Flood WarningFFCForsyth, Fulton40 hr
Apr 15, 11:44 PM EDTRiver Flood WarningFFCCobb6 hr
Apr 16, 12:17 AM EDTRiver Flood WarningFFCForsyth14 hr
Apr 16, 12:47 AM EDTRiver Flood WarningFFCDade34 hr
Apr 16, 1:25 AM EDTSevere Thunderstorm WarningFFCHeard, Troup50 min
Apr 16, 1:40 AM EDTSevere Thunderstorm WarningFFCBartow, Carroll, Haralson, Paulding50 min
Apr 16, 1:54 AM EDTSevere Thunderstorm WarningFFCCarroll, Coweta, Fulton, Meriwether51 min
Apr 16, 2:10 AM EDTTornado WarningFFCCarroll, Cobb, Douglas, Fulton, Paulding50 min
Apr 16, 2:38 AM EDTSevere Thunderstorm WarningFFCClayton, DeKalb, Fayette, Fulton, Henry, Newton and 1 more52 min
Apr 16, 2:46 AM EDTSevere Thunderstorm WarningFFCHarris44 min
Apr 16, 3:15 AM EDTSevere Thunderstorm WarningFFCHarris, Muscogee45 min
Apr 16, 3:26 AM EDTSevere Thunderstorm WarningFFCMeriwether49 min
Apr 16, 3:35 AM EDTWind AdvisoryFFCBaldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 90 more16 hr
Apr 16, 3:39 AM EDTTornado WarningFFCHarris, Talbot36 min
Apr 16, 3:51 AM EDTSevere Thunderstorm WarningFFCLamar, Meriwether, Pike, Spalding39 min
Apr 16, 4:04 AM EDTSevere Thunderstorm WarningFFCMeriwether, Pike, Talbot, Upson26 min
Apr 16, 4:40 AM EDTSevere Thunderstorm WarningFFCChattahoochee, Macon, Marion, Muscogee, Talbot50 min
Apr 16, 4:45 AM EDTTornado WarningFFCChattahoochee, Marion, Muscogee45 min
Apr 16, 5:12 AM EDTSevere Thunderstorm WarningFFCChattahoochee, Crawford, Marion, Talbot, Taylor, Upson48 min
Apr 16, 5:48 AM EDTTornado WarningFFCBibb, Crawford, Monroe, Taylor42 min
Apr 16, 6:14 AM EDTTornado WarningFFCBaldwin, Jones, Putnam46 min
Apr 16, 6:26 AM EDTRiver Flood WarningFFCWhitfield64 hr
Apr 16, 8:42 AM EDTRiver Flood WarningFFCCobb7 hr
Apr 16, 10:34 AM EDTRiver Flood WarningFFCGordon, Murray, Whitfield28 hr

Nearby

Tornado Warnings in Georgia, 2011Every tornado warning in 2011Tornadoes 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.