Alert archive / Georgia / Flash Flood Warnings in 2012

Flash Flood Warning 16, NWS Atlanta, GA

August 2, 2012DeKalb County, Fulton County, Georgia

NWS Atlanta, GA issued this flash flood warning at Aug 2, 2012, 8:05 PM EDT for DeKalb County, Fulton County, Georgia. It was in force for 4 hr. 1 report 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 2, 2012, 8:05 PM EDT (00:05 UTC)
Expired
Aug 2, 2012, 11:35 PM EDT
In force
4 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

Counties DeKalb County, GA, Fulton County, GA

The radar

The Atlanta radar (KFFC), 53 km from the middle of the area, began a volume at 00:06 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 2, 8:20 PM EDTFLASH FLOOD3 N Druid Hills, GASOCIAL MEDIA SITES PROVIDED VIDEO OF FLASH FLOODING IN THE NORTH DRUID HILLS AREA. VIDEOS SHOW STREAMS OVER FLOWING...ROADS COVERED IN EXCESS OF TWO FEET OF WATER ALONG WITH FLOODED YARDS.

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, 0.1 hours before the alert went out and 51 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 2012-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 872 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 2012-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 107 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
872 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
1131 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
107 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

387 
WGUS52 KFFC 030005
FFWFFC
GAC089-121-030600-
/O.NEW.KFFC.FF.W.0016.120803T0005Z-120803T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
805 PM EDT THU AUG 2 2012

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  CENTRAL FULTON COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 200 AM EDT

* AT 801 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BUCKHEAD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS IN EXCESS OF ONE INCH ARE LIKELY 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.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY...THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

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 3382 8442 3386 8439 3386 8430 3375 8428
      3376 8440

$$
2 follow-up statements
626 
WGUS72 KFFC 030105
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
905 PM EDT THU AUG 2 2012

GAC089-121-030600-
/O.CON.KFFC.FF.W.0016.000000T0000Z-120803T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DEKALB GA-FULTON GA-
905 PM EDT THU AUG 2 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 200 AM EDT FOR
CENTRAL FULTON AND WEST CENTRAL DEKALB COUNTIES...

AT 857 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETERMINED 
THAT THE CONTINUED RAINFALL THREAT HAS GREATLY DIMINISHED BUT FLASH 
FLOODING CONCERNS WILL CONTINUE. RADAR AND GAUGE ESTIMATES INDICATE 
THAT AROUND 3 INCHES OF RAIN FELL BETWEEN LA VISTA AND MIDTOWN.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BUCKHEAD

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.

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.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY...THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

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 3382 8442 3386 8439 3386 8430 3375 8428
      3376 8440

$$
550 
WGUS72 KFFC 030335
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1135 PM EDT THU AUG 2 2012

GAC089-121-030344-
/O.CAN.KFFC.FF.W.0016.000000T0000Z-120803T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DEKALB GA-FULTON GA-
1135 PM EDT THU AUG 2 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL FULTON AND
WEST CENTRAL DEKALB COUNTIES...

ALTHOUGH ADDITIONAL RAINFALL IS NOT EXPECTED TONIGHT AND STREAMS AND 
CREEKS REMAIN WITHIN THEIR BANKS...STANDING WATER MAY REMAIN IN 
LOCATIONS WHERE OVER THREE INCHES OF RAIN FELL.

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 3382 8442 3386 8439 3386 8430 3375 8428
      3376 8440

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 8:53 PM EDTSpecial Weather StatementFFCSpalding52 min
Aug 3, 5:35 PM EDTSpecial Weather StatementFFCCobb40 min
Aug 3, 6:11 PM EDTSpecial Weather StatementFFCUnion34 min
Aug 3, 6:42 PM EDTSpecial Weather StatementFFCDeKalb, Gwinnett33 min
Aug 3, 6:51 PM EDTSevere Thunderstorm WarningFFCDeKalb, Gwinnett, Rockdale, Walton39 min
Aug 3, 7:36 PM EDTSpecial Weather StatementFFCFayette39 min
Aug 3, 7:44 PM EDTSevere Thunderstorm WarningFFCClayton, DeKalb, Fayette, Fulton, Henry46 min
Aug 3, 7:59 PM EDTSpecial Weather StatementFFCGwinnett46 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.