Alert archive / Georgia / Flash Flood Warnings in 2009

Flash Flood Warning 47, NWS Atlanta, GA

September 26, 20094 counties in Georgia

NWS Atlanta, GA issued this flash flood warning at Sep 26, 2009, 5:00 PM EDT for 4 counties in Georgia. It was in force for 4 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
Sep 26, 2009, 5:00 PM EDT (21:00 UTC)
Expired
Sep 26, 2009, 8:42 PM EDT
In force
4 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

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

The radar

The Atlanta radar (KFFC), 62 km from the middle of the area, began a volume at 21:03 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, 9.0 hours before the alert went out and 60 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 2009-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1105 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 2009-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
1105 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
824 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

000 
WGUS52 KFFC 262100
FFWFFC
GAC089-117-121-135-270300-
/O.NEW.KFFC.FF.W.0047.090926T2100Z-090927T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
500 PM EDT SAT SEP 26 2009

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DEKALB COUNTY IN NORTH CENTRAL GEORGIA
  SOUTHERN FORSYTH COUNTY IN NORTH CENTRAL GEORGIA
  FULTON COUNTY IN NORTH CENTRAL GEORGIA
  GWINNETT COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 1100 PM EDT

* AT 454 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A LINE OF THUNDERSTORMS WITH HEAVY RAIN FROM ALPHARETTA THROUGH    
  ATLANTA AND DOUGLASVILLE TO WHITESBURG. HEAVY RAINFALL AMOUNTS UP  
  TO TWO INCHES MAY OCCUR IN ONE HOUR AS THESE STORMS MOVE THROUGH   
  THE WARNED AREA. THIS MAY CAUSE SOME FLASH FLOODING OF SMALL       
  STREAMS AND CREEKS DUE TO SATURATED SOILS. RAINFALL AMOUNTS UP TO  
  ONE INCH HAVE ALREADY OCCURRED TODAY IN THE WARNED AREA. THIS AREA 
  IS STILL RECOVERING FROM FLOODING EARLIER THIS WEEK AND MAY HAVE
  DEBRIS BLOCKAGE OF STORM DRAINS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  DORAVILLE...MOUNTAIN PARK...SUWANEE...SUGAR HILL...REST HAVEN...
  NORCROSS...LAWRENCEVILLE...DULUTH...DACULA...BUFORD...BERKELEY
  LAKE...DUNWOODY...JOHNS CREEK...MILTON...SANDY SPRINGS...ROSWELL...
  ALPHARETTA AND CUMMING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 3363 8475 3366 8467 3383 8446 3390 8444
      3397 8437 3410 8442 3419 8433 3419 8426
      3426 8426 3422 8398 3418 8406 3410 8383
      3400 8386 3393 8380 3372 8406 3362 8412
      3365 8427 3365 8445 3356 8446 3352 8483

$$
2 follow-up statements
000 
WGUS72 KFFC 262338
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
738 PM EDT SAT SEP 26 2009

GAC089-117-121-135-270300-
/O.CON.KFFC.FF.W.0047.000000T0000Z-090927T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DEKALB GA-GWINNETT GA-FORSYTH GA-FULTON GA-
738 PM EDT SAT SEP 26 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
FULTON...SOUTHERN FORSYTH...GWINNETT AND DEKALB COUNTIES...

AT 730 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATES 
ONLY LIGHT RAIN PASSING OVER THE WARNED AREA AND THIS WILL CONTINUE 
FOR ANOTHER HOUR OR TWO. TOTAL RAINFALL AMOUNTS OF 1 TO 2 INCHES 
OCCURRED IN THE WARNED AREA...WITH UP TO 3 INCHES IN SOUTHWEST 
DEKALB AND NORTHEAST GWINNETT COUNTIES. 

THE NORTH FORK PEACHTREE CREEK AT BUFORD HIGHWAY REACHED 12.1 FEET 
AT 715 PM EDT...AND WAS IN MINOR FLOOD. FLOOD STAGE IS 12 FEET. 
THE CREEK WILL CONTINUE TO RISE SLOWLY TO NEAR 12.5 FEET IN THE 
NEXT HOUR THEN FALL BELOW FLOOD STAGE BY 1000 PM EDT.

SEVERAL PUBLIC REPORTS OF TEMPORARY STREET FLOODING HAVE BEEN 
RECEIVED. NANCY CREEK IN ATLANTA...CROOKED CREEK NEAR NORCROSS
AND PEW CREEK NEAR LAWRENCEVILLE WERE ABOVE BANKFULL AND SLOWLY
RISING. ALL OF THESE CREEKS SHOULD CREST JUST BELOW THEIR 
RESPECTIVE FLOOD STAGES IN THE NEXT FEW HOURS.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO GRAYSON...
SUWANEE...SUGAR HILL...REST HAVEN...NORCROSS...LAWRENCEVILLE...
DULUTH...DACULA...BUFORD...BERKELEY LAKE...DORAVILLE...DUNWOODY...
JOHNS CREEK...MILTON...SANDY SPRINGS...ROSWELL...ALPHARETTA AND
CUMMING

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU SEE SIGNIFICANT FLOODING CALL THE NATIONAL WEATHER SERVICE
TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

&&

LAT...LON 3363 8475 3366 8467 3383 8446 3390 8444
      3397 8437 3410 8442 3419 8433 3419 8426
      3426 8426 3422 8398 3418 8406 3410 8383
      3400 8386 3393 8380 3372 8406 3362 8412
      3365 8427 3365 8445 3356 8446 3352 8483

$$
000 
WGUS72 KFFC 270042
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
842 PM EDT SAT SEP 26 2009

GAC089-117-121-135-270055-
/O.CAN.KFFC.FF.W.0047.000000T0000Z-090927T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DEKALB GA-GWINNETT GA-FORSYTH GA-FULTON GA-
842 PM EDT SAT SEP 26 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR FULTON...SOUTHERN
FORSYTH...GWINNETT AND DEKALB COUNTIES...

AT 840 PM EDT...RADAR INDICATES ONLY SPOTTY LIGHT RAIN PASSING OVER 
THE PREVIOUSLY WARNED AREA. THE TEMPORARY STREET FLOODING...SMALL 
STREAM AND CREEK FLOODING THAT OCCURRED EARLIER WITH THE HEAVY RAIN 
HAVE RECEDED.

AT 815 PM EDT...THE NORTH FORK PEACHTREE CREEK AT BUFORD HIGHWAY WAS 
AT 11.8 FEET AND FALLING. FLOOD STAGE IS 12 FEET. THE CREEK CRESTED 
AT 12.1 FEET AT 715 PM EDT. THE CREEK WILL CONTINUE TO FALL.

LAT...LON 3363 8475 3366 8467 3383 8446 3390 8444
      3397 8437 3410 8442 3419 8433 3419 8426
      3426 8426 3422 8398 3418 8406 3410 8383
      3400 8386 3393 8380 3372 8406 3362 8412
      3365 8427 3365 8445 3356 8446 3352 8483

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 26, 2:56 AM EDTFlash Flood WarningFFCMurray, Whitfield6 hr
Sep 26, 9:15 AM EDTFlash Flood WarningFFCChattooga, Floyd, Gordon, Murray, Walker, Whitfield6 hr
Sep 26, 12:21 PM EDTFlash Flood WarningFFCCatoosa, Chattooga, Dade, Floyd, Walker, Whitfield6 hr
Sep 26, 3:24 PM EDTAreal Flood WarningFFCGordon, Murray, Whitfield4 hr
Sep 26, 3:47 PM EDTFlash Flood WarningFFCCarroll, Cherokee, Cobb, Douglas, Paulding6 hr
Sep 26, 4:20 PM EDTSevere Thunderstorm WarningFFCHeard40 min
Sep 26, 5:26 PM EDTRiver Flood WarningFFCGordon, Murray, Whitfield3 days
Sep 26, 5:46 PM EDTSevere Thunderstorm WarningFFCMorgan44 min
Sep 26, 6:20 PM EDTSevere Thunderstorm WarningFFCPutnam40 min
Sep 26, 6:35 PM EDTSevere Thunderstorm WarningFFCBaldwin, Jones40 min
Sep 26, 6:40 PM EDTSevere Thunderstorm WarningFFCChattahoochee, Marion, Muscogee, Talbot39 min
Sep 26, 6:50 PM EDTRiver Flood WarningFFCMurray, Whitfield44 hr
Sep 26, 6:50 PM EDTRiver Flood WarningFFCWhitfield69 hr

Nearby

Flash Flood Warnings in Georgia, 2009Every flash flood warning in 2009

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.