Alert archive / Georgia / Flash Flood Warnings in 2009

Flash Flood Warning 4, NWS Atlanta, GA

June 4, 2009Gwinnett County, Georgia

NWS Atlanta, GA issued this flash flood warning at Jun 4, 2009, 11:14 PM EDT for Gwinnett County, Georgia. It was in force for 3 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
Jun 4, 2009, 11:14 PM EDT (03:14 UTC)
Expired
Jun 5, 2009, 1:56 AM EDT
In force
3 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

County Gwinnett County, GA

The radar

The Atlanta radar (KFFC), 89 km from the middle of the area, began a volume at 03:18 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, 3.2 hours before the alert went out and 85 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 2009-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 987 joules per kilogram.LCLEL10008507005003002001001 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 2009-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 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
987 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
490 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
11 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.

000 
WGUS52 KFFC 050314
FFWFFC
GAC135-050715-
/O.NEW.KFFC.FF.W.0004.090605T0314Z-090605T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1114 PM EDT THU JUN 4 2009

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL GWINNETT COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 315 AM EDT

* AT 1110 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A BAND OF HEAVY RAIN OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  LAWRENCEVILLE...SUGAR HILL AND BUFORD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PEW CREEK IS RISING RAPIDLY JUST SOUTHWEST OF LAWRENCEVILLE AND IS 
EXPECTED TO CREST BETWEEN 11 FEET AND 12 FEET. FLOOD STAGE ON PEW 
CREEK SOUTHWEST OF LAWRENCEVILLE IS 11 FEET. PEW CREEK SHOULD DROP 
BELOW FLOOD STAGE BY 3 AM. 

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.

&&

LAT...LON 3414 8403 3408 8387 3383 8396 3387 8412

$$
1 follow-up statement
000 
WGUS72 KFFC 050556
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
156 AM EDT FRI JUN 5 2009

GAC135-050630-
/O.CAN.KFFC.FF.W.0004.000000T0000Z-090605T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GWINNETT GA-
156 AM EDT FRI JUN 5 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL GWINNETT
COUNTY...

PEW CREEK JUST SOUTHWEST OF LAWRENCEVILLE CRESTED AT 10.8 FEET AT 
1215 AM EDT. FLOOD STAGE IS 11 FEET. THE CREEK HAS STEADILY FALLEN 
SINCE THEN AND HAS DROPPED TO 7.3 FEET AS OF 145 AM EDT. THE MORE 
WIDESPREAD HEAVY RAIN SHOWERS HAVE MOVED WELL EAST OF GWINNETT 
COUNTY AND FURTHER FLOODING IS NOT EXPECTED TONIGHT.

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

LAT...LON 3414 8403 3408 8387 3383 8396 3387 8412

$$

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.