Alert archive / Georgia / Special Weather Statements in 2012

Special Weather Statement, NWS Atlanta, GA

September 18, 2012Johnson County, Laurens County, Wilkinson County, Georgia

NWS Atlanta, GA issued this special weather statement at Sep 18, 2012, 12:21 AM EDT for Johnson County, Laurens County, Wilkinson County, Georgia. It was in force for 24 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 18, 2012, 12:21 AM EDT (04:21 UTC)
Expired
Sep 18, 2012, 12:45 AM EDT
In force
24 min
Issued by
NWS Atlanta, GA

Counties Johnson County, GA, Laurens County, GA, Wilkinson County, GA

The radar

The Robins AFB radar (KJGX), 34 km from the middle of the area, began a volume at 04:22 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 00:00Z, 4.4 hours before the alert went out and 157 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 00:00Z on 2012-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 405 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 00:00Z on 2012-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 220 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
405 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
706 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
220 m²/s²
0-3 km storm-relative helicity
203 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

752 
WWUS82 KFFC 180421
SPSFFC

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1221 AM EDT TUE SEP 18 2012

GAZ073-074-083>085-096-097-109-180445-
1221 AM EDT TUE SEP 18 2012

...SIGNIFICANT WEATHER ADVISORY FOR 40 MPH WINDS IN WASHINGTON...
TWIGGS...LAURENS...JOHNSON...WILKINSON...BALDWIN...BLECKLEY AND DODGE
COUNTIES UNTIL 1245 AM EDT...

AT 1217 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
LINE OF SHOWERS WITH STRONG WINDS FROM 5 MILES NORTH OF DANVILLE TO 
CADWELL...MOVING NORTHEAST AT 35 MPH.

WIND GUSTS OF 40 MPH ARE LIKELY AS THIS ACTIVITY MOVES ACROSS 
WASHINGTON...TWIGGS...LAURENS...JOHNSON...WILKINSON...BALDWIN...BLECK
LEY AND DODGE COUNTIES THROUGH 1245 AM EDT. SOME LOCATIONS IN THE 
PATH OF THESE STORMS INCLUDE 
RENTZ...MONTROSE...DEXTER...CADWELL...ALLENTOWN...DANVILLE...JEFFERSO
NVILLE...DUDLEY...HARLOW...NICKLESVILLE...MCINTYRE...CHAPPELLS 
MILL...IRWINTON...MINTER AND EAST DUBLIN.

&&

LAT...LON 3307 8299 3298 8283 3265 8257 3222 8304
      3251 8320 3269 8336
TIME...MOT...LOC 0421Z 212DEG 32KT 3271 8323 3261 8314
          3238 8300

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 1:06 AM EDTSpecial Weather StatementFFCDade54 min
Sep 18, 3:27 AM EDTRiver Flood WarningFFCDade15 hr
Sep 18, 6:25 AM EDTSpecial Weather StatementFFCChattooga65 min
Sep 18, 7:18 AM EDTSpecial Weather StatementFFCMarion, Schley, Webster42 min
Sep 18, 7:52 AM EDTSpecial Weather StatementFFCCrawford, Macon, Peach, Schley38 min
Sep 18, 8:22 AM EDTSpecial Weather StatementFFCBaldwin, Jones23 min
Sep 18, 11:33 AM EDTSpecial Weather StatementFFCCoweta, Troup27 min
Sep 18, 11:57 AM EDTSpecial Weather StatementFFCClayton, Coweta, Fayette33 min
Sep 18, 1:29 PM EDTSpecial Weather StatementFFCButts, Spalding46 min
Sep 18, 2:16 PM EDTSpecial Weather StatementFFCMonroe, Upson29 min
Sep 18, 2:46 PM EDTSpecial Weather StatementFFCBibb, Jones, Monroe29 min
Sep 18, 3:42 PM EDTSpecial Weather StatementFFCHancock, Putnam48 min

Nearby

Special Weather Statements in Georgia, 2012Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.