Alert archive / Georgia / Flash Flood Warnings in 2013

Flash Flood Warning 62, NWS Atlanta, GA

July 21, 2013Cobb County, Douglas County, Fulton County, Georgia

NWS Atlanta, GA issued this flash flood warning at Jul 21, 2013, 7:01 PM EDT for Cobb County, Douglas County, Fulton County, 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
Jul 21, 2013, 7:01 PM EDT (23:01 UTC)
Expired
Jul 22, 2013, 1:00 AM EDT
In force
6 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

Counties Cobb County, GA, Douglas County, GA, Fulton County, GA

The radar

The Atlanta radar (KFFC), 46 km from the middle of the area, began a volume at 23:01 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, 11.0 hours before the alert went out and 47 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 2013-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 966 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 2013-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 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
966 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
487 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
1 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.

252 
WGUS52 KFFC 212301
FFWFFC
GAC067-097-121-220500-
/O.NEW.KFFC.FF.W.0062.130721T2301Z-130722T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
701 PM EDT SUN JUL 21 2013

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL COBB COUNTY IN NORTH CENTRAL GEORGIA
  EASTERN DOUGLAS COUNTY IN NORTH CENTRAL GEORGIA
  CENTRAL FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 100 AM EDT MONDAY

* AT 656 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  2.5 TO 3 INCHES OF RAIN HAD FALLEN OVER PORTIONS OF EASTERN        
  DOUGLAS COUNTY SINCE 5 PM EDT...WITH LOCALLY HIGHER                
  AMOUNTS...RESULTING IN FLASH FLOODING.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  DOUGLASVILLE...LITHIA SPRINGS...AUSTELL AND SMYRNA....INCLUDING    
  AREAS IN THE CHATTAHOOCHEE...SWEETWATER CREEK...SLATER MILL        
  CREEK...AND LITTLE BEAR CREEK BASINS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 0.5 TO 1.0 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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 3379 8475 3379 8473 3380 8472 3392 8443
      3381 8441 3359 8474 3362 8481 3376 8482

$$
1 follow-up statement
900 
WGUS72 KFFC 220243
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1043 PM EDT SUN JUL 21 2013

GAC067-097-121-220251-
/O.CAN.KFFC.FF.W.0062.000000T0000Z-130722T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COBB GA-DOUGLAS GA-FULTON GA-
1043 PM EDT SUN JUL 21 2013

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL FULTON...
EASTERN DOUGLAS AND SOUTH CENTRAL COBB COUNTIES...

NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATES INDICATE 3 TO 4 
INCHES OF RAIN FELL ACROSS EASTERN DOUGLAS...WITH SLIGHTLY LOWER 
AMOUNTS IN FULTON AND COBB COUNTIES. MANY OF THE RIVERS AND CREEKS 
IN THE AREA THAT HAD RISEN AS A RESULT HAVE NOW CREST AND ARE ON 
THEIR WAY BACK DOWN. A FEW LIGHT RAIN SHOWERS ARE STILL POSSIBLE 
OVERNIGHT...WITH ADDITIONAL RAINFALL AMOUNTS GENERALLY A TENTH OF AN 
INCH OR LESS. AT THIS TIME...THE RISK OF FLASH FLOODING HAS 
DIMINISHED ACROSS THE AREA.

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 3379 8475 3379 8473 3380 8472 3392 8443
      3381 8441 3359 8474 3362 8481 3376 8482

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:28 PM EDTSpecial Weather StatementFFCOconee, Oglethorpe32 min
Jul 21, 2:36 PM EDTSpecial Weather StatementFFCWheeler24 min
Jul 21, 2:40 PM EDTSpecial Weather StatementFFCMacon35 min
Jul 21, 3:10 PM EDTSpecial Weather StatementFFCCrisp35 min
Jul 21, 4:15 PM EDTSpecial Weather StatementFFCSchley30 min
Jul 21, 4:26 PM EDTSpecial Weather StatementFFCFannin34 min
Jul 21, 5:27 PM EDTSpecial Weather StatementFFCMeriwether33 min
Jul 21, 5:32 PM EDTSpecial Weather StatementFFCCoweta28 min
Jul 21, 5:49 PM EDTSpecial Weather StatementFFCFayette26 min
Jul 21, 5:52 PM EDTSevere Thunderstorm WarningFFCCoweta, Fayette38 min
Jul 21, 6:00 PM EDTSpecial Weather StatementFFCClayton, DeKalb, Fulton30 min
Jul 21, 6:15 PM EDTSpecial Weather StatementFFCHenry30 min
Jul 21, 6:19 PM EDTSevere Thunderstorm WarningFFCButts, Clayton, Henry, Spalding41 min

Nearby

Flash Flood Warnings in Georgia, 2013Every flash flood warning in 2013

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.