Alert archive / Georgia / Flash Flood Warnings in 2018

Flash Flood Warning 47, NWS Atlanta, GA

November 12, 20184 counties in Georgia

NWS Atlanta, GA issued this flash flood warning at Nov 12, 2018, 5:10 PM EST for 4 counties in Georgia. It was in force for 6 hr. 2 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
Nov 12, 2018, 5:10 PM EST (22:10 UTC)
Expired
Nov 12, 2018, 11:15 PM EST
In force
6 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

Counties Dawson County, GA, Forsyth County, GA, Gilmer County, GA, Lumpkin County, GA

The radar

The Atlanta radar (KFFC), 130 km from the middle of the area, began a volume at 22:13 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
Nov 12, 5:10 PM ESTFLASH FLOOD3 Ne Coal Mountain, GATHE ROADWAY NEAR SETTINGDOWN ROAD AND HAMPTON PARK DRIVE WAS REPORTED TO HAVE WATER ON THE ROADWAY.
Nov 12, 5:10 PM ESTFLASH FLOODBrookwood, GAMULTIPLE ROADS WERE REPORTED WITH WATER IN THE ROADWAY INCLUDING NEAR THE INTERSECTION OF CANEY ROAD AND CHRISTOPHER ROBIN RD AS WELL AS VAUGHAN DRIVE AND BROOKWOOD ROAD.

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, 10.2 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-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 12:00Z on 2018-11-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2018-11-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 189 square meters per square second.1939587897Sfc1 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
445 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
189 m²/s²
0-3 km storm-relative helicity
278 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

818 
WGUS52 KFFC 122210
FFWFFC
GAC085-117-123-187-130415-
/O.NEW.KFFC.FF.W.0047.181112T2210Z-181113T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Peachtree City GA
510 PM EST MON NOV 12 2018

The National Weather Service in Peachtree City has issued a

* Flash Flood Warning for...
  Forsyth County in north central Georgia...
  Lumpkin County in north central Georgia...
  Southeastern Gilmer County in north central Georgia...
  Dawson County in north central Georgia...

* Until 1115 PM EST Monday.

* At 508 PM EST, several reports of water over roadways have 
  occurred in an area that received up to three inches of heavy 
  rain. An additional half to one inch may fall this evening as 
  well. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Cumming, Dahlonega, Dawsonville, Alpharetta, Sugar Hill, Suwanee,
  Dougherty, Amicalola Falls State Park, Drew, Coal Mountain,
  Brookwood, Hightower, Juno, Fausett Lake, Matt, Len Foote Hike Inn,
  Cartecay, Turners Corner, War Hill Park and McKee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 3462 8388 3452 8383 3441 8398 3428 8393
      3420 8399 3419 8405 3415 8408 3405 8410
      3411 8426 3447 8426 3447 8432 3456 8435
      3455 8445 3467 8438 3468 8425 3460 8419
      3466 8413 3464 8404 3469 8399 3470 8386

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 12, 1:08 PM ESTRiver Flood WarningFFCForsyth, Fulton4 days
Nov 12, 1:32 PM ESTRiver Flood WarningFFCGwinnett24 hr
Nov 12, 1:37 PM ESTRiver Flood WarningFFCFulton, Gwinnett9 hr
Nov 12, 1:42 PM ESTRiver Flood WarningFFCCobb24 hr
Nov 12, 2:27 PM ESTFlood WatchFFCBanks, Barrow, Bartow, Carroll, Catoosa, Chattooga and 38 more12 hr
Nov 12, 3:09 PM ESTRiver Flood WarningFFCForsyth24 hr
Nov 12, 3:37 PM ESTRiver Flood WarningFFCGwinnett9 hr
Nov 12, 3:50 PM ESTRiver Flood WarningFFCCherokee, Cobb24 hr
Nov 12, 4:00 PM ESTRiver Flood WarningFFCPolk24 hr
Nov 12, 4:05 PM ESTRiver Flood WarningFFCCobb24 hr
Nov 12, 4:39 PM ESTFlash Flood WarningFFCBartow, Carroll, Cherokee, Cobb, Floyd, Fulton and 4 more6 hr
Nov 12, 4:56 PM ESTRiver Flood WarningFFCCobb24 hr
Nov 12, 5:18 PM ESTRiver Flood WarningFFCCobb, Fulton13 hr
Nov 12, 6:02 PM ESTRiver Flood WarningFFCCobb, Fulton9 hr
Nov 12, 6:21 PM ESTRiver Flood WarningFFCDawson, Forsyth15 hr
Nov 12, 6:31 PM ESTRiver Flood WarningFFCCherokee15 hr
Nov 12, 6:38 PM ESTRiver Flood WarningFFCCobb24 hr
Nov 12, 6:52 PM ESTRiver Flood WarningFFCFulton24 hr
Nov 12, 6:59 PM ESTRiver Flood WarningFFCGwinnett, Walton24 hr

Nearby

Flash Flood Warnings in Georgia, 2018Every flash flood warning in 2018

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.