Alert archive / Georgia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 177, NWS Atlanta, GA

May 12, 2017Barrow County, Gwinnett County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at May 12, 2017, 6:43 PM EDT for Barrow County, Gwinnett County, Georgia. It was in force for 47 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
May 12, 2017, 6:43 PM EDT (22:43 UTC)
Expired
May 12, 2017, 7:30 PM EDT
In force
47 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

The radar

The Atlanta radar (KFFC), 91 km from the middle of the area, began a volume at 22:44 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, 10.7 hours before the alert went out and 87 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 2017-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2017-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1299 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

396 
WUUS52 KFFC 122243
SVRFFC
GAC013-135-122330-
/O.NEW.KFFC.SV.W.0177.170512T2243Z-170512T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Peachtree City GA
643 PM EDT FRI MAY 12 2017

The National Weather Service in Peachtree City has issued a

* Severe Thunderstorm Warning for...
  Southwestern Barrow County in north central Georgia...
  East central Gwinnett County in north central Georgia...

* Until 730 PM EDT

* At 643 PM EDT, a severe thunderstorm was located over Grayson, or
  over Lawrenceville, moving northeast 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...
  Lawrenceville, Snellville, Auburn, Dacula, Grayson, Carl and
  Harbin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3402 8381 3394 8379 3389 8385 3385 8398
      3393 8405 3404 8389
TIME...MOT...LOC 2243Z 231DEG 12KT 3392 8398 

HAIL...1.00IN
WIND...60MPH
 
$$
2 follow-up statements
126 
WWUS52 KFFC 122253
SVSFFC

Severe Weather Statement
National Weather Service Peachtree City GA
653 PM EDT FRI MAY 12 2017

GAC013-135-122330-
/O.CON.KFFC.SV.W.0177.000000T0000Z-170512T2330Z/
Barrow GA-Gwinnett GA-
653 PM EDT FRI MAY 12 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR SOUTHWESTERN BARROW AND EAST CENTRAL GWINNETT COUNTIES...

At 653 PM EDT, a severe thunderstorm was located over Lawrenceville,
moving northeast at 15 mph.

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

SOURCE...Radar indicated. 

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

Locations impacted include...
Lawrenceville, Auburn, Dacula, Grayson, Carl and Harbin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3402 8381 3394 8379 3389 8385 3386 8394
      3395 8402 3404 8389
TIME...MOT...LOC 2253Z 231DEG 12KT 3394 8395 

HAIL...0.75IN
WIND...60MPH
 
$$
027 
WWUS52 KFFC 122321
SVSFFC

Severe Weather Statement
National Weather Service Peachtree City GA
721 PM EDT FRI MAY 12 2017

GAC013-135-122331-
/O.EXP.KFFC.SV.W.0177.000000T0000Z-170512T2330Z/
Barrow GA-Gwinnett GA-
721 PM EDT FRI MAY 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN BARROW AND EAST
CENTRAL GWINNETT COUNTIES WILL EXPIRE AT 730 PM EDT...
                
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 will be allowed to expire.

LAT...LON 3402 8381 3394 8379 3389 8385 3386 8394
      3395 8402 3404 8389
TIME...MOT...LOC 2321Z 231DEG 12KT 3399 8387 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 2:17 PM EDTSpecial Weather StatementFFCCatoosa, Walker28 min
May 12, 3:46 PM EDTSpecial Weather StatementFFCPolk29 min
May 12, 4:13 PM EDTSpecial Weather StatementFFCHaralson47 min
May 12, 4:21 PM EDTSpecial Weather StatementFFCBartow24 min
May 12, 4:46 PM EDTSpecial Weather StatementFFCCherokee44 min
May 12, 5:22 PM EDTSpecial Weather StatementFFCCobb, Paulding23 min
May 12, 5:45 PM EDTSpecial Weather StatementFFCForsyth30 min
May 12, 6:11 PM EDTSpecial Weather StatementFFCGwinnett34 min
May 12, 6:15 PM EDTSevere Thunderstorm WarningFFCDeKalb, Gwinnett30 min
May 12, 6:25 PM EDTSpecial Weather StatementFFCHall50 min
May 12, 7:01 PM EDTSpecial Weather StatementFFCBanks29 min
May 12, 7:47 PM EDTSpecial Weather StatementFFCChattooga43 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2017Every severe thunderstorm warning in 2017

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.