Alert archive / Georgia / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 321, NWS Atlanta, GA

September 26, 20184 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Sep 26, 2018, 5:08 PM EDT for 4 counties in Georgia. It was in force for 29 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
Sep 26, 2018, 5:08 PM EDT (21:08 UTC)
Expired
Sep 26, 2018, 5:37 PM EDT
In force
29 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Barrow County, GA, Gwinnett County, GA, Hall County, GA, Jackson County, GA

The radar

The Atlanta radar (KFFC), 105 km from the middle of the area, began a volume at 21:10 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, 9.1 hours before the alert went out and 101 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 2018-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 903 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 2018-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
903 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
681 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

803 
WUUS52 KFFC 262108
SVRFFC
GAC013-135-139-157-262200-
/O.NEW.KFFC.SV.W.0321.180926T2108Z-180926T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Peachtree City GA
508 PM EDT WED SEP 26 2018

The National Weather Service in Peachtree City has issued a

* Severe Thunderstorm Warning for...
  Central Barrow County in north central Georgia...
  Northeastern Gwinnett County in north central Georgia...
  Southeastern Hall County in north central Georgia...
  Western Jackson County in northeastern Georgia...

* Until 600 PM EDT.

* At 508 PM EDT, a severe thunderstorm was located over Hog Mountain,
  or 10 miles northeast of Lawrenceville, moving east at 15 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Winder, Jefferson, Sugar Hill, Buford, Braselton, Auburn, Flowery
  Branch, Dacula, Hoschton, Pendergrass, Carl, Talmo, Rest Haven,
  Candler, County Line, Thompsons Mill, Chateau Elan, Chestnut
  Mountain, Road Atlanta-Lanier Speedway and Hog Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

If you see wind damage...hail or 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 or tweet us your report at NWSATLANTA.

&&

LAT...LON 3399 8401 3413 8403 3425 8375 3417 8356
      3398 8361
TIME...MOT...LOC 2108Z 248DEG 15KT 3408 8391 

HAIL...1.00IN
WIND...60MPH
 
$$
2 follow-up statements
557 
WWUS52 KFFC 262131
SVSFFC

Severe Weather Statement
National Weather Service Peachtree City GA
531 PM EDT WED SEP 26 2018

GAC135-262140-
/O.CAN.KFFC.SV.W.0321.000000T0000Z-180926T2200Z/
Gwinnett GA-
531 PM EDT WED SEP 26 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN GWINNETT COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3417 8356 3398 8361 3399 8383 3408 8384
      3412 8382 3412 8384 3421 8385 3422 8384
      3425 8375
TIME...MOT...LOC 2130Z 248DEG 15KT 3412 8380 

$$

GAC013-139-157-262200-
/O.CON.KFFC.SV.W.0321.000000T0000Z-180926T2200Z/
Barrow GA-Hall GA-Jackson GA-
531 PM EDT WED SEP 26 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR CENTRAL BARROW...SOUTHEASTERN HALL AND WESTERN JACKSON
COUNTIES...

At 530 PM EDT, a severe thunderstorm was located over Thompsons Mill,
or 9 miles northwest of Winder, moving east at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Winder, Jefferson, Braselton, Auburn, Hoschton, Pendergrass, Carl,
Talmo, Candler, County Line, Thompsons Mill, Chateau Elan, Chestnut
Mountain and Road Atlanta-Lanier Speedway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3417 8356 3398 8361 3399 8383 3408 8384
      3412 8382 3412 8384 3421 8385 3422 8384
      3425 8375
TIME...MOT...LOC 2130Z 248DEG 15KT 3412 8380 

HAIL...<.75IN
WIND...60MPH
 
$$
207 
WWUS52 KFFC 262137
SVSFFC

Severe Weather Statement
National Weather Service Peachtree City GA
537 PM EDT WED SEP 26 2018

GAC013-139-157-262146-
/O.CAN.KFFC.SV.W.0321.000000T0000Z-180926T2200Z/
Barrow GA-Hall GA-Jackson GA-
537 PM EDT WED SEP 26 2018

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL BARROW...SOUTHEASTERN
HALL AND WESTERN JACKSON COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.

LAT...LON 3417 8356 3398 8361 3399 8383 3408 8384
      3412 8382 3412 8384 3421 8385 3422 8384
      3425 8375
TIME...MOT...LOC 2135Z 248DEG 15KT 3413 8377 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 26, 3:44 AM EDTFlash Flood WatchFFCBartow, Catoosa, Chattooga, Dade, Fannin, Floyd and 9 more40 hr
Sep 26, 1:38 PM EDTSpecial Weather StatementFFCChattooga, Floyd, Walker37 min
Sep 26, 3:05 PM EDTSpecial Weather StatementFFCCarroll25 min
Sep 26, 4:17 PM EDTSpecial Weather StatementFFCClayton28 min
Sep 26, 4:24 PM EDTSpecial Weather StatementFFCTroup36 min
Sep 26, 4:35 PM EDTSpecial Weather StatementFFCHenry40 min
Sep 26, 4:53 PM EDTSpecial Weather StatementFFCGwinnett37 min
Sep 26, 5:08 PM EDTSpecial Weather StatementFFCNewton, Rockdale, Walton37 min
Sep 26, 5:20 PM EDTSpecial Weather StatementFFCCoweta40 min
Sep 26, 5:35 PM EDTSpecial Weather StatementFFCBanks25 min
Sep 26, 5:36 PM EDTSpecial Weather StatementFFCMorgan, Oconee, Walton39 min
Sep 26, 7:27 PM EDTSpecial Weather StatementFFCHeard, Troup63 min
Sep 26, 7:46 PM EDTSpecial Weather StatementFFCHancock29 min
Sep 26, 7:52 PM EDTSevere Thunderstorm WarningFFCHancock, Warren38 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2018Every severe thunderstorm warning in 2018

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.