Alert archive / Georgia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 176, NWS Atlanta, GA

May 12, 2017DeKalb County, Gwinnett County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at May 12, 2017, 6:15 PM EDT for DeKalb County, Gwinnett County, Georgia. It was in force for 30 min. 1 report 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: May 12, 2017, 6:15 PM EDT (22:15 UTC)
Expired: May 12, 2017, 6:45 PM EDT
In force: 30 min
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties DeKalb County, GA, Gwinnett County, GA

The radar

The Atlanta radar (KFFC), 80 km from the middle of the area, began a volume at 22:19 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

Time	Report	Where	Remark
May 12, 6:23 PM EDT	HAIL 1	Lester Woods, GA	1 INCH HAIL WAS REPORTED NEAR MURPHY USA GAS STATION IN LILBURN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 10.3 hours before the alert went out and 76 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: 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.

487 
WUUS52 KFFC 122215
SVRFFC
GAC089-135-122245-
/O.NEW.KFFC.SV.W.0176.170512T2215Z-170512T2245Z/

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

The National Weather Service in Peachtree City has issued a

* Severe Thunderstorm Warning for...
  Central DeKalb County in north central Georgia...
  Central Gwinnett County in north central Georgia...

* Until 645 PM EDT

* At 615 PM EDT, a severe thunderstorm was located over Lilburn, or 9
  miles northeast of Decatur, 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, Duluth, Sugar Hill, Snellville, Suwanee, Lilburn,
  Norcross, Stone Mountain, Grayson, Tucker and Mountain Park.

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 3411 8406 3391 8384 3379 8417 3387 8424
TIME...MOT...LOC 2215Z 232DEG 13KT 3386 8416 

HAIL...1.00IN
WIND...60MPH
 
$$

1 follow-up statement

098 
WWUS52 KFFC 122227
SVSFFC

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

GAC089-122237-
/O.CAN.KFFC.SV.W.0176.000000T0000Z-170512T2245Z/
DeKalb GA-
627 PM EDT FRI MAY 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL DEKALB 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 3407 8409 3390 8386 3384 8403 3382 8409
      3386 8416 3391 8421
TIME...MOT...LOC 2227Z 231DEG 14KT 3390 8411 

$$

GAC135-122245-
/O.CON.KFFC.SV.W.0176.000000T0000Z-170512T2245Z/
Gwinnett GA-
627 PM EDT FRI MAY 12 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR CENTRAL GWINNETT COUNTY...

At 627 PM EDT, a severe thunderstorm was located over Lilburn, or 7
miles southwest of 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, Duluth, Snellville, Suwanee, Lilburn, Norcross,
Grayson and Mountain Park.

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 3407 8409 3390 8386 3384 8403 3382 8409
      3386 8416 3391 8421
TIME...MOT...LOC 2227Z 231DEG 14KT 3390 8411 

HAIL...1.00IN
WIND...60MPH
 
$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 12, 2:17 PM EDT	Special Weather Statement	FFC	Catoosa, Walker	28 min
May 12, 3:46 PM EDT	Special Weather Statement	FFC	Polk	29 min
May 12, 4:13 PM EDT	Special Weather Statement	FFC	Haralson	47 min
May 12, 4:21 PM EDT	Special Weather Statement	FFC	Bartow	24 min
May 12, 4:46 PM EDT	Special Weather Statement	FFC	Cherokee	44 min
May 12, 5:22 PM EDT	Special Weather Statement	FFC	Cobb, Paulding	23 min
May 12, 5:45 PM EDT	Special Weather Statement	FFC	Forsyth	30 min
May 12, 6:11 PM EDT	Special Weather Statement	FFC	Gwinnett	34 min
May 12, 6:25 PM EDT	Special Weather Statement	FFC	Hall	50 min
May 12, 6:43 PM EDT	Severe Thunderstorm Warning	FFC	Barrow, Gwinnett	47 min
May 12, 7:01 PM EDT	Special Weather Statement	FFC	Banks	29 min
May 12, 7:47 PM EDT	Special Weather Statement	FFC	Chattooga	43 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2017 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.