Alert archive / Georgia / Flash Flood Warnings in 2017

Flash Flood Warning 39, NWS Atlanta, GA

August 9, 2017DeKalb County, Fulton County, Gwinnett County, Georgia

NWS Atlanta, GA issued this flash flood warning at Aug 9, 2017, 6:05 AM EDT for DeKalb County, Fulton County, Gwinnett County, Georgia. It was in force for 6 hr. 5 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
Aug 9, 2017, 6:05 AM EDT (10:05 UTC)
Expired
Aug 9, 2017, 12:00 PM EDT
In force
6 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

Counties DeKalb County, GA, Fulton County, GA, Gwinnett County, GA

The radar

The Atlanta radar (KFFC), 71 km from the middle of the area, began a volume at 10:05 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
Aug 9, 7:15 AM EDTHEAVY RAIN 3.243 Nw Clarkston, GACOCORAHS STATION GA-DK-7, NORTH DECATUR 3.0 NNE. ENDING 8 AM.
Aug 9, 7:30 AM EDTHEAVY RAIN 4.021 Sse Dunwoody, GACOCORAHS STATION GA-DK-36, 1 SSE DUNWOODY. ENDING 8 AM
Aug 9, 8:19 AM EDTHEAVY RAIN 4.322 E Tucker, GAMESONET STATION F0560, 2 E TUCKER.
Aug 9, 9:45 AM EDTFLASH FLOODWindsor At Peachtree, GAMEDIA REPORTED THAT THE WINDSOR PKWY BRIDGE OVER NANCY CREEK HAD SEVERAL FEET OF WATER OVER IT DURING PEAK FLOODING ON WEDNESDAY
Aug 9, 11:15 AM EDTFLASH FLOOD1 S East Conway Hill, GAA PROPERTY ON NORTHSIDE DRIVE WAS INUNDATED WITH FLOOD WATERS FROM THE ADJACENT NANCY CREEK. THE WATER WAS RAPIDLY MOVING ACROSS THEIR ENTIRE FRONT YARD AND DRIVEWAY... CUTTING OFF ALL SAFE INGRESS AND EGRESS FROM THE PROPERTY.

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 00:00Z, 10.1 hours before the alert went out and 67 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 2017-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 295 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 2017-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 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
295 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
627 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
-9 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted.

574 
WGUS52 KFFC 091005
FFWFFC
GAC089-121-135-091600-
/O.NEW.KFFC.FF.W.0039.170809T1005Z-170809T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Peachtree City GA
605 AM EDT WED AUG 9 2017

The National Weather Service in Peachtree City has issued a

* Flash Flood Warning for...
  Northern DeKalb County in north central Georgia...
  Southwestern Gwinnett County in north central Georgia...
  East central Fulton County in north central Georgia...

* Until noon EDT

* At 603 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. One to two inches of rain have already fallen in the 
  past one to two hours. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Atlanta, Lawrenceville, Sandy Springs, Roswell, Dunwoody, Duluth,
  Snellville, Lilburn, Chamblee, Norcross, Doraville, Clarkston,
  Stone Mountain, Berkeley Lake, Pine Lake, Tucker, North Decatur,
  North Atlanta, North Druid Hills and Druid Hills.

Additional rainfall amounts of one to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 or tweet us your report at
NWSATLANTA.

&&

LAT...LON 3400 8405 3386 8401 3375 8407 3382 8440
      3394 8440 3403 8434

$$
1 follow-up statement
152 
WGUS72 KFFC 091553
FFSFFC

Flash Flood Statement
National Weather Service Peachtree City GA
1153 AM EDT WED AUG 9 2017

GAC089-121-135-091603-
/O.EXP.KFFC.FF.W.0039.000000T0000Z-170809T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DeKalb GA-Gwinnett GA-Fulton GA-
1153 AM EDT WED AUG 9 2017

...THE FLASH FLOOD WARNING FOR NORTHERN DEKALB...SOUTHWESTERN
GWINNETT AND EAST CENTRAL FULTON COUNTIES WILL EXPIRE AT NOON EDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3400 8405 3386 8401 3375 8407 3382 8440
      3394 8440 3403 8434

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 5:16 AM EDTSpecial Weather StatementFFCDeKalb, Fulton, Gwinnett59 min
Aug 9, 5:19 AM EDTSpecial Weather StatementFFCHancock, Putnam, Taliaferro, Warren56 min
Aug 9, 6:11 AM EDTSpecial Weather StatementFFCHancock64 min
Aug 9, 7:08 AM EDTSpecial Weather StatementFFCBaldwin, Hancock, Putnam, Warren67 min
Aug 9, 7:12 AM EDTRiver Flood WarningFFCDeKalb, Fulton24 hr
Aug 9, 7:20 AM EDTSpecial Weather StatementFFCRockdale55 min
Aug 9, 7:36 AM EDTFlash Flood WarningFFCBaldwin, Hancock6 hr
Aug 9, 9:25 AM EDTRiver Flood WarningFFCDeKalb, Fulton24 hr
Aug 9, 9:36 AM EDTSpecial Weather StatementFFCWashington54 min
Aug 9, 9:43 AM EDTRiver Flood WarningFFCFulton, Gwinnett24 hr
Aug 9, 10:12 AM EDTSpecial Weather StatementFFCWilkinson48 min
Aug 9, 11:03 AM EDTSpecial Weather StatementFFCTwiggs, Wilkinson42 min
Aug 9, 12:49 PM EDTSpecial Weather StatementFFCEmanuel, Treutlen26 min
Aug 9, 1:03 PM EDTSevere Thunderstorm WarningFFCEmanuel27 min
Aug 9, 1:22 PM EDTSpecial Weather StatementFFCDodge, Emanuel, Laurens, Treutlen23 min
Aug 9, 1:50 PM EDTSpecial Weather StatementFFCDodge, Emanuel, Laurens, Treutlen25 min
Aug 9, 4:59 PM EDTSpecial Weather StatementFFCChattahoochee31 min
Aug 9, 5:41 PM EDTSpecial Weather StatementFFCStewart, Sumter, Webster34 min
Aug 9, 5:44 PM EDTSpecial Weather StatementFFCHarris, Troup31 min
Aug 9, 7:05 PM EDTSpecial Weather StatementFFCTroup25 min

Nearby

Flash Flood Warnings in Georgia, 2017Every flash flood warning in 2017

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.