Alert archive / Georgia / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 122, NWS Atlanta, GA

May 20, 2012Clayton County, DeKalb County, Fulton County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at May 20, 2012, 7:00 PM EDT for Clayton County, DeKalb County, Fulton County, Georgia. It was in force for 31 min. 3 reports 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 20, 2012, 7:00 PM EDT (23:00 UTC)
Expired
May 20, 2012, 7:31 PM EDT
In force
31 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon

Counties Clayton County, GA, DeKalb County, GA, Fulton County, GA

The radar

The Atlanta radar (KFFC), 45 km from the middle of the area, began a volume at 23:00 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

TimeReportWhereRemark
May 20, 7:20 PM EDTHAIL 14 S Atlanta, GAMARBLE TO QUARTER SIZE HAIL WAS REPORTED BY THE MEDIA ON LANGFORD PARKWAY SOUTH OF DOWNTOWN ATLANTA
May 20, 7:25 PM EDTHAIL 0.881 E Lakewood Park, GAPUBLIC REPORTED DIME TO NICKEL SIZED HAIL IN LAKEWOOD HEIGHTS AROUND 1925 EDT.
May 20, 7:40 PM EDTTSTM WND DMG3 Ene Decatur, GADEKALB COUNTY 911 RELAYED A REPORT OF A TREE DOWNED ON MONTREAL ROAD. RADAR ESTIMATED TIME BETWEEN 1940 EDT AND 1945 EDT.

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, 11.0 hours before the alert went out and 41 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 2012-05-20Temperature 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 2012-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -29 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1433 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-29 m²/s²
0-3 km storm-relative helicity
16 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.

864 
WUUS52 KFFC 202300
SVRFFC
GAC063-089-121-202345-
/O.NEW.KFFC.SV.W.0122.120520T2300Z-120520T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
700 PM EDT SUN MAY 20 2012

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN CLAYTON COUNTY IN NORTH CENTRAL GEORGIA
  WESTERN DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  CENTRAL FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 745 PM EDT

* AT 655 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZED HAIL...AND
  DAMAGING WINDS UP TO 60 MPH.  THIS STORM WAS LOCATED NEAR
  DECATUR...MOVING SOUTHWEST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MIDTOWN...ATLANTA...GRANT PARK-ZOO ATLANTA...EAST POINT...
  HAPEVILLE...FOREST PARK...COLLEGE PARK...HARTSFIELD-JACKSON AIRPORT
  AND LAKE CITY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

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. YOU CAN ALSO TWEET YOUR REPORT USING HASHTAG GAWX.

&&

LAT...LON 3389 8431 3384 8420 3365 8424 3364 8428
      3363 8426 3359 8425 3358 8425 3358 8426
      3366 8452
TIME...MOT...LOC 2300Z 026DEG 14KT 3377 8430

$$
1 follow-up statement
821 
WWUS52 KFFC 202331
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
731 PM EDT SUN MAY 20 2012

GAC063-089-121-202341-
/O.CAN.KFFC.SV.W.0122.000000T0000Z-120520T2345Z/
DEKALB GA-CLAYTON GA-FULTON GA-
731 PM EDT SUN MAY 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL FULTON...NORTHERN
CLAYTON AND WESTERN DEKALB COUNTIES IS CANCELLED...

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO EAST
POINT...ELLENWOOD...HAPEVILLE...FORT GILLEM...REX...FOREST PARK...
COLLEGE PARK...HARTSFIELD-JACKSON AIRPORT AND LAKE CITY.

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. YOU CAN ALSO TWEET YOUR REPORT USING HASHTAG GAWX.

LAT...LON 3389 8431 3384 8420 3365 8424 3364 8428
      3363 8426 3359 8425 3358 8425 3358 8426
      3366 8452
TIME...MOT...LOC 2331Z 026DEG 14KT 3366 8436

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 8:28 PM EDTSpecial Weather StatementFFCTowns, Union32 min
May 20, 3:55 PM EDTSpecial Weather StatementFFCWalker35 min
May 20, 5:02 PM EDTSpecial Weather StatementFFCForsyth, Gwinnett28 min
May 20, 5:31 PM EDTSpecial Weather StatementFFCForsyth29 min
May 20, 6:08 PM EDTSpecial Weather StatementFFCDeKalb, Fulton37 min
May 20, 6:09 PM EDTSpecial Weather StatementFFCLumpkin36 min
May 20, 6:27 PM EDTSevere Thunderstorm WarningFFCForsyth22 min
May 20, 6:46 PM EDTSpecial Weather StatementFFCDeKalb29 min
May 20, 7:28 PM EDTSpecial Weather StatementFFCUnion32 min
May 20, 7:36 PM EDTSpecial Weather StatementFFCClayton, Fayette24 min
May 20, 7:58 PM EDTSpecial Weather StatementFFCCoweta, Fayette32 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2012Every severe thunderstorm warning in 2012

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.