Alert archive / Georgia / Flash Flood Warnings in 2011

Flash Flood Warning 13, NWS Atlanta, GA

October 12, 2011Jefferson County, Georgia

NWS Atlanta, GA issued this flash flood warning at Oct 12, 2011, 1:50 AM EDT for Jefferson County, Georgia. It was in force for 6 hr. 2 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: Oct 12, 2011, 1:50 AM EDT (05:50 UTC)
Expired: Oct 12, 2011, 7:45 AM EDT
In force: 6 hr
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Flood severity: None

County Jefferson County, GA

The radar

The Robins AFB radar (KJGX), 99 km from the middle of the area, began a volume at 05:53 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

Time	Report	Where	Remark
Oct 12, 2:35 AM EDT	FLASH FLOOD	1 Ne Stapleton, GA	SHERIFF DEPUTY REPORTED WATER FLOWING OVER HIGHWAY 296 JUST NORTHEAST OF STAPLETON.
Oct 12, 2:40 AM EDT	FLASH FLOOD	1 Ne Wrens, GA	SHERIFF DEPUTY REPORTED WATER OVER HIGHWAY 1 JUST NORTHEAST OF WRENS.

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, 5.8 hours before the alert went out and 192 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 465 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 81 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.

177 
WGUS52 KFFC 120550
FFWFFC
GAC163-121145-
/O.NEW.KFFC.FF.W.0013.111012T0550Z-111012T1145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
150 AM EDT WED OCT 12 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  JEFFERSON COUNTY IN EAST CENTRAL GEORGIA

* UNTIL 745 AM EDT

* AT 148 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  POSSIBLE FLASH FLOODING FROM SLOW MOVING THUNDERSTORMS OVER THE 
  WARNED AREA.  

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WRENS...
  STAPLETON AND AVERA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

3 TO 4 INCHES OF RAIN HAVE FALLEN OVER THE WARNED AREA IN A SHORT 
PERIOD OF TIME AND ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE 
POSSIBLE.

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS...OR WATERS OF UNKNOWN DEPTH...ON FOOT OR IN
AN AUTOMOBILE.

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 3311 8228 3301 8228 3295 8254 3302 8255
      3303 8260 3312 8266 3312 8258 3316 8257
      3317 8259 3318 8257 3332 8239 3332 8234
      3327 8226 3323 8223

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 12, 1:14 AM EDT	Special Weather Statement	FFC	Jefferson, Washington	91 min

Nearby

Flash Flood Warnings in Georgia, 2011 Every flash flood warning in 2011

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.