Alert archive / Georgia / Flash Flood Warnings in 2012

Flash Flood Warning 19, NWS Atlanta, GA

August 24, 20124 counties in Georgia

NWS Atlanta, GA issued this flash flood warning at Aug 24, 2012, 1:12 AM EDT for 4 counties in Georgia. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 24, 2012, 1:12 AM EDT (05:12 UTC)
Expired
Aug 24, 2012, 7:15 AM EDT
In force
6 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

Counties Banks County, GA, Hall County, GA, Lumpkin County, GA, White County, GA

The radar

The Greer radar (KGSP), 141 km from the middle of the area, began a volume at 05:15 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, 5.2 hours before the alert went out and 147 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 2012-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 516 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 2012-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
516 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1473 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
38 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.

042 
WGUS52 KFFC 240512
FFWFFC
GAC011-139-187-311-241115-
/O.NEW.KFFC.FF.W.0019.120824T0512Z-120824T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
112 AM EDT FRI AUG 24 2012

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN HALL COUNTY IN NORTH CENTRAL GEORGIA
  SOUTHEASTERN LUMPKIN COUNTY IN NORTH CENTRAL GEORGIA
  EXTREME WEST CENTRAL BANKS COUNTY IN NORTHEAST GEORGIA
  SOUTHERN WHITE COUNTY IN NORTHEAST GEORGIA

* UNTIL 715 AM EDT

* AT 101 AM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS INDICATED 
FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA ESTIMATED TO 
PRODUCE 3 TO 4 INCHES OF RAINFALL WITHIN AN HOUR.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO CLEVELAND 
AND CLERMONT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...AS WELL AS HIGHWAYS AND UNDERPASSES.
ADDITIONALLY...COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF
CREEKS...STREAMS AND OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING.

IF YOU SEE SIGNIFICANT FLOODING 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 3460 8363 3456 8362 3453 8362 3451 8365
      3450 8365 3446 8362 3440 8363 3441 8389
      3452 8391 3461 8387

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 24, 12:46 AM EDTSpecial Weather StatementFFCHall44 min
Aug 24, 1:18 AM EDTSevere Thunderstorm WarningFFCDawson, Forsyth, Hall, Lumpkin42 min
Aug 24, 2:06 AM EDTSpecial Weather StatementFFCForsyth39 min
Aug 24, 2:36 AM EDTSpecial Weather StatementFFCGwinnett39 min
Aug 24, 4:09 PM EDTSpecial Weather StatementFFCUnion36 min
Aug 24, 4:46 PM EDTSpecial Weather StatementFFCUnion29 min
Aug 24, 4:50 PM EDTSpecial Weather StatementFFCFannin25 min
Aug 24, 4:55 PM EDTSpecial Weather StatementFFCTowns35 min
Aug 24, 5:37 PM EDTSpecial Weather StatementFFCFannin23 min
Aug 24, 6:04 PM EDTSpecial Weather StatementFFCFannin26 min
Aug 24, 6:21 PM EDTSpecial Weather StatementFFCDouglas24 min

Nearby

Flash Flood Warnings in Georgia, 2012Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.