Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 21, NWS Atlanta, GA

February 28, 20115 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Feb 28, 2011, 6:12 PM EST for 5 counties in Georgia. It was in force for 33 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: Feb 28, 2011, 6:12 PM EST (23:12 UTC)
Expired: Feb 28, 2011, 6:45 PM EST
In force: 33 min
Issued by: NWS Atlanta, GA
Area: Storm-based polygon

Counties Clayton County, GA, DeKalb County, GA, Henry County, GA, Newton County, GA, Rockdale County, GA

The radar

The Atlanta radar (KFFC), 44 km from the middle of the area, began a volume at 23:13 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.

Issued	Product	Office	Lasted
Feb 28, 1:29 PM EST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 11.2 hours before the alert went out and 39 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1162 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 229 m²/s²
0-3 km storm-relative helicity: 350 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.

411 
WUUS52 KFFC 282312
SVRFFC
GAC063-089-151-217-247-282345-
/O.NEW.KFFC.SV.W.0021.110228T2312Z-110228T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
612 PM EST MON FEB 28 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN CLAYTON COUNTY IN NORTH CENTRAL GEORGIA
  SOUTHERN DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  NORTHERN HENRY COUNTY IN NORTH CENTRAL GEORGIA
  WESTERN NEWTON COUNTY IN NORTH CENTRAL GEORGIA
  ROCKDALE COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 645 PM EST

* AT 609 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS UP TO 60
  MPH.  THIS STORM WAS LOCATED NEAR HARTSFIELD-JACKSON AIRPORT...
  MOVING EAST AT 65 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  RIVERDALE...FOREST PARK...LAKE CITY...MORROW...STOCKBRIDGE...
  LITHONIA...LAKEVIEW ESTATES...CONYERS AND GEORGIA INTERNATIONAL
  HORSE PARK.

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 TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM EST MONDAY EVENING FOR
NORTHERN GEORGIA.

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1000 PM EST
MONDAY EVENING FOR NORTHERN GEORGIA.

&&

LAT...LON 3365 8434 3375 8434 3374 8390 3373 8389
      3347 8392 3354 8443 3356 8445 3364 8445
TIME...MOT...LOC 2311Z 276DEG 60KT 3365 8446

$$

16

1 follow-up statement

344 
WWUS52 KFFC 282341
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
641 PM EST MON FEB 28 2011

GAC089-282349-
/O.CAN.KFFC.SV.W.0021.000000T0000Z-110228T2345Z/
DEKALB GA-
641 PM EST MON FEB 28 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN DEKALB COUNTY HAS 
BEEN CANCELLED...

MODERATE RAIN AND OCCASIONAL CLOUD-TO-GROUND LIGHTNING CAN BE 
EXPECTED ACROSS SOUTHERN DEKALB COUNTY DURING THE NEXT HOUR. 
HOWEVER...SEVERE THUNDERSTORMS ARE NO LONGER EXPECTED AT THIS TIME.

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 800 PM EST MONDAY EVENING FOR
NORTHERN GEORGIA.

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1000 PM EST
MONDAY EVENING FOR NORTHERN GEORGIA.

LAT...LON 3364 8445 3365 8427 3364 8423 3365 8422
      3364 8414 3362 8412 3374 8404 3374 8390
      3373 8389 3347 8392 3354 8443 3356 8445
TIME...MOT...LOC 2339Z 276DEG 60KT 3360 8390

$$

GAC063-151-217-247-282345-
/O.CON.KFFC.SV.W.0021.000000T0000Z-110228T2345Z/
HENRY GA-CLAYTON GA-NEWTON GA-ROCKDALE GA-
641 PM EST MON FEB 28 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EST
FOR ROCKDALE...WESTERN NEWTON...NORTHERN CLAYTON AND NORTHERN HENRY
COUNTIES...

AT 637 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A LINE OF SEVERE THUNDERSTORMS FROM CONYERS...TO THE 
ATLANTA HARTSFIELD-JACKSON INTERNATIONAL AIRPORT...MOVING EAST AT 70 
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 TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM EST MONDAY EVENING FOR
NORTHERN GEORGIA.

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1000 PM EST
MONDAY EVENING FOR NORTHERN GEORGIA.

&&

LAT...LON 3364 8445 3365 8427 3364 8423 3365 8422
      3364 8414 3362 8412 3374 8404 3374 8390
      3373 8389 3347 8392 3354 8443 3356 8445
TIME...MOT...LOC 2339Z 276DEG 60KT 3360 8390

$$



19

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 28, 4:04 AM EST	Wind Advisory	FFC	Baldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 90 more	15 hr
Feb 28, 2:25 PM EST	Severe Thunderstorm Warning	FFC	Catoosa, Dade, Walker	50 min
Feb 28, 2:45 PM EST	Severe Thunderstorm Warning	FFC	Murray, Whitfield	45 min
Feb 28, 3:08 PM EST	Severe Thunderstorm Warning	FFC	Chattooga, Dade, Floyd, Walker	37 min
Feb 28, 3:13 PM EST	Severe Thunderstorm Warning	FFC	Fannin, Gilmer	32 min
Feb 28, 3:29 PM EST	Severe Thunderstorm Warning	FFC	Towns, Union	31 min
Feb 28, 3:42 PM EST	Severe Thunderstorm Warning	FFC	Bartow, Chattooga, Floyd, Gordon	48 min
Feb 28, 3:50 PM EST	Severe Thunderstorm Warning	FFC	Bartow, Floyd, Polk	25 min
Feb 28, 4:09 PM EST	Severe Thunderstorm Warning	FFC	Bartow, Cherokee, Pickens	51 min
Feb 28, 4:17 PM EST	Severe Thunderstorm Warning	FFC	Bartow, Floyd	13 min
Feb 28, 4:32 PM EST	Tornado Warning	FFC	Bartow, Cherokee, Cobb, Paulding	28 min
Feb 28, 4:40 PM EST	Severe Thunderstorm Warning	FFC	Dawson, Forsyth, Hall	50 min
Feb 28, 4:56 PM EST	Tornado Warning	FFC	Cherokee, Cobb, Forsyth, Fulton	35 min
Feb 28, 5:04 PM EST	Severe Thunderstorm Warning	FFC	Carroll, Haralson, Paulding, Polk	41 min
Feb 28, 5:16 PM EST	Severe Thunderstorm Warning	FFC	Banks, Barrow, Clarke, Gwinnett, Hall, Jackson and 3 more	44 min
Feb 28, 5:49 PM EST	Severe Thunderstorm Warning	FFC	Carroll, Cobb, Douglas, Fulton, Paulding	41 min
Feb 28, 5:55 PM EST	Tornado Warning	FFC	Douglas, Fulton	35 min
Feb 28, 6:36 PM EST	Severe Thunderstorm Warning	FFC	Meriwether, Troup	39 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2011 Every 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.