Alert archive / Georgia / Flash Flood Warnings in 2014

Flash Flood Warning 25, NWS Atlanta, GA

August 9, 20144 counties in Georgia

NWS Atlanta, GA issued this flash flood warning at Aug 9, 2014, 9:49 PM 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 9, 2014, 9:49 PM EDT (01:49 UTC)
Expired: Aug 10, 2014, 3:45 AM EDT
In force: 6 hr
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Flood severity: None

Counties Dawson County, GA, Forsyth County, GA, Hall County, GA, Lumpkin County, GA

The radar

The Atlanta radar (KFFC), 130 km from the middle of the area, began a volume at 01:50 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, 1.8 hours before the alert went out and 127 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 321 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 1237 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -68 m²/s²
0-3 km storm-relative helicity: -3 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.

240 
WGUS52 KFFC 100149
FFWFFC
GAC085-117-139-187-100745-
/O.NEW.KFFC.FF.W.0025.140810T0149Z-140810T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
949 PM EDT SAT AUG 9 2014

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN DAWSON COUNTY IN NORTH CENTRAL GEORGIA
  FORSYTH COUNTY IN NORTH CENTRAL GEORGIA
  HALL COUNTY IN NORTH CENTRAL GEORGIA
  SOUTHEASTERN LUMPKIN COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 345 AM EDT

* AT 947 PM EDT...VERY HEAVY RAIN WAS REPORTED FROM A THUNDERSTORM
  OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LULA...
  CLERMONT...DAHLONEGA AND DAWSONVILLE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

IF YOU SEE SIGNIFICANT FLOODING 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 3456 8386 3453 8383 3450 8384 3452 8378
      3450 8365 3441 8363 3439 8366 3436 8367
      3429 8363 3410 8386 3417 8406 3416 8408
      3419 8426 3434 8425 3456 8402

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 8:00 PM EDT	Special Weather Statement	FFC	DeKalb	30 min
Aug 9, 8:20 PM EDT	Flash Flood Warning	FFC	DeKalb, Fulton, Gwinnett	6 hr
Aug 9, 8:27 PM EDT	Special Weather Statement	FFC	DeKalb, Gwinnett	63 min
Aug 9, 8:58 PM EDT	Special Weather Statement	FFC	Forsyth, Hall	62 min
Aug 9, 9:56 PM EDT	Special Weather Statement	FFC	Baldwin	64 min
Aug 9, 9:59 PM EDT	Special Weather Statement	FFC	White	61 min
Aug 9, 10:25 PM EDT	Special Weather Statement	FFC	Washington	65 min
Aug 10, 3:37 PM EDT	Special Weather Statement	FFC	DeKalb, Rockdale	23 min
Aug 10, 3:53 PM EDT	Flash Flood Warning	FFC	DeKalb, Henry, Rockdale	6 hr
Aug 10, 7:05 PM EDT	Special Weather Statement	FFC	Houston, Peach	55 min
Aug 10, 7:29 PM EDT	Special Weather Statement	FFC	Crawford	61 min

Nearby

Flash Flood Warnings in Georgia, 2014 Every flash flood warning in 2014

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.