Alert archive / Georgia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 348, NWS Atlanta, GA

December 20, 20175 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Dec 20, 2017, 12:44 PM EST for 5 counties in Georgia. It was in force for 31 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
Dec 20, 2017, 12:44 PM EST (17:44 UTC)
Expired
Dec 20, 2017, 1:15 PM EST
In force
31 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Tornado
Possible
Hail
0.88 in
Wind
60.0 mph

Counties Coweta County, GA, Fayette County, GA, Meriwether County, GA, Pike County, GA, Spalding County, GA

The radar

The Atlanta radar (KFFC), 16 km from the middle of the area, began a volume at 17:48 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, 5.7 hours before the alert went out and 18 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 2017-12-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 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 2017-12-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 242 square meters per square second.1939587897Sfc1 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
11 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
572 m above ground
0-6 km bulk shear
76 kt
0-1 km storm-relative helicity
242 m²/s²
0-3 km storm-relative helicity
276 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

210 
WUUS52 KFFC 201744
SVRFFC
GAC077-113-199-231-255-201815-
/O.NEW.KFFC.SV.W.0348.171220T1744Z-171220T1815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Peachtree City GA
1244 PM EST WED DEC 20 2017

The National Weather Service in Peachtree City has issued a

* Severe Thunderstorm Warning for...
  Southwestern Spalding County in west central Georgia...
  Northeastern Meriwether County in west central Georgia...
  South central Fayette County in north central Georgia...
  Northwestern Pike County in west central Georgia...
  Southeastern Coweta County in west central Georgia...

* Until 115 PM EST

* At 1243 PM EST, a severe thunderstorm was located over Digbey, or
  13 miles northwest of Zebulon, moving southeast at 50 mph.

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

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Senoia, Brooks, Haralson, Alvaton and Digbey. 

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 3320 8467 3333 8457 3326 8441 3310 8452
TIME...MOT...LOC 1743Z 293DEG 42KT 3323 8453 

TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
 
$$

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 19, 7:34 PM ESTDense Fog AdvisoryFFCBaldwin, Bartow, Bibb, Bleckley, Butts, Carroll and 76 more11 hr
Dec 20, 11:52 AM ESTSpecial Weather StatementFFCHeard, Troup23 min
Dec 20, 12:11 PM ESTSpecial Weather StatementFFCGreene34 min
Dec 20, 12:15 PM ESTSpecial Weather StatementFFCCoweta, Meriwether, Troup30 min
Dec 20, 12:33 PM ESTSpecial Weather StatementFFCHarris27 min
Dec 20, 12:47 PM ESTSpecial Weather StatementFFCGreene, Taliaferro, Warren43 min
Dec 20, 12:50 PM ESTSevere Thunderstorm WarningFFCHarris, Meriwether, Troup25 min
Dec 20, 1:09 PM ESTSevere Thunderstorm WarningFFCLamar, Meriwether, Pike, Upson36 min
Dec 20, 1:24 PM ESTSpecial Weather StatementFFCGlascock, Warren51 min
Dec 20, 1:27 PM ESTSevere Thunderstorm WarningFFCChattahoochee, Harris, Marion, Muscogee, Talbot48 min
Dec 20, 1:45 PM ESTSpecial Weather StatementFFCButts, Jasper, Jones, Lamar, Monroe, Putnam45 min
Dec 20, 2:10 PM ESTSpecial Weather StatementFFCCrawford, Talbot, Taylor50 min
Dec 20, 2:30 PM ESTSpecial Weather StatementFFCBaldwin, Hancock, Jones30 min
Dec 20, 2:55 PM ESTSpecial Weather StatementFFCPeach, Twiggs35 min
Dec 20, 3:01 PM ESTSpecial Weather StatementFFCGlascock, Washington29 min
Dec 20, 3:22 PM ESTSpecial Weather StatementFFCJohnson38 min
Dec 20, 3:43 PM ESTSpecial Weather StatementFFCJefferson, Washington32 min
Dec 20, 4:01 PM ESTSpecial Weather StatementFFCJohnson, Laurens29 min
Dec 20, 4:36 PM ESTSpecial Weather StatementFFCEmanuel, Treutlen24 min
Dec 20, 5:52 PM ESTSpecial Weather StatementFFCCobb, Douglas, Fulton, Heard23 min
Dec 20, 6:20 PM ESTSpecial Weather StatementFFCClayton, Coweta, Fayette, Troup25 min
Dec 20, 6:50 PM ESTSpecial Weather StatementFFCClayton, DeKalb, Fayette, Henry, Meriwether, Newton and 3 more25 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.