Alert archive / Georgia / Flash Flood Warnings in 2010

Flash Flood Warning 22, NWS Atlanta, GA

September 27, 2010Gwinnett County, Georgia

NWS Atlanta, GA issued this flash flood warning at Sep 27, 2010, 8:57 PM EDT for Gwinnett County, Georgia. It was in force for 65 min. 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 27, 2010, 8:57 PM EDT (00:57 UTC)
Expired
Sep 27, 2010, 10:02 PM EDT
In force
65 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

County Gwinnett County, GA

The radar

The Atlanta radar (KFFC), 93 km from the middle of the area, began a volume at 00:58 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, 1.0 hours before the alert went out and 90 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 2010-09-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 200 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 2010-09-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
200 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
1287 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

010 
WGUS52 KFFC 280057
FFWFFC
GAC135-280645-
/O.NEW.KFFC.FF.W.0022.100928T0057Z-100928T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
857 PM EDT MON SEP 27 2010

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

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

* UNTIL 245 AM EDT

* AT 848 PM EDT...THE WATER LEVEL ON LEVEL CREEK THREE MILES NNW OF
  SUWANEE WAS AT 8.7 FEET...AND RISING. FLOOD STAGE IS 9.0 FEET.

* WHILE RAIN HAS ENDED IN THIS AREA...THUNDERSTORMS WHICH MOVED 
THROUGH
  THE AREA EARLIER TODAY DUMPED AN ADDITIONAL 1 TO 1.25 INCHES OF 
RAIN
  IN THE LEVEL CREEK BASIN. THIS RAINFALL WAS IN ADDITION TO THE 2 
TO 3
  INCHES OF RAIN THAT FELL ACROSS THIS AREA SUNDAY THROUGH EARLY 
MONDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE STAGE ON LEVEL CREEK NEAR SUWANEE IS EXPECTED TO RISE TO 9.0 FEET
WITHIN THE NEXT HOUR. DO NOT ATTEMPT TO CROSS WATER COVERED 
BRIDGES...DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A 
FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER 
MOVE UP 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 3410 8411 3411 8408 3411 8404 3410 8402
      3409 8405 3408 8407 3407 8411

$$
1 follow-up statement
353 
WGUS72 KFFC 280202
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1002 PM EDT MON SEP 27 2010

GAC135-280208-
/O.CAN.KFFC.FF.W.0022.000000T0000Z-100928T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GWINNETT GA-
1002 PM EDT MON SEP 27 2010

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

LEVEL CREEK THREE NORTH-NORTHWEST OF SUWANEE REACHED 8.9 FEET AND 
HAS NOW FALLEN TO 8.7 FEET AND CONTINUES TO FALL. THE CREEK IS 
EXPECTED TO REMAIN BELOW FLOOD STAGE...THUS FLASH FLOODING IS NO 
LONGER EXPECTED AT THIS TIME.

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

LAT...LON 3410 8411 3411 8408 3411 8404 3410 8402
      3409 8405 3408 8407 3407 8411

$$



19

Nearby

Flash Flood Warnings in Georgia, 2010Every flash flood warning in 2010

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.