Alert archive / Georgia / Flash Flood Watches in 2012

Flash Flood Watch 1, NWS Atlanta, GA

January 21, 201219 counties in Georgia

NWS Atlanta, GA issued this flash flood watch at Jan 21, 2012, 11:07 AM EST for 19 counties in Georgia. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Jan 21, 2012, 11:07 AM EST (16:07 UTC)
Expired
Jan 21, 2012, 2:38 PM EST
In force
4 hr
Issued by
NWS Atlanta, GA
Flood severity
None

Counties Barrow County, GA, Carroll County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, DeKalb County, GA, Douglas County, GA, Fayette County, GA, Forsyth County, GA, Fulton County, GA, Gwinnett County, GA, Haralson County, GA, Heard County, GA, Henry County, GA, Newton County, GA, Paulding County, GA, Rockdale County, GA, Spalding County, GA, Walton County, GA

The radar

The Atlanta radar (KFFC), 38 km from the middle of the area, began a volume at 16:07 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, 4.1 hours before the alert went out and 36 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 2012-01-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 238 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 2012-01-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 265 square meters per square second.1939587897Sfc1 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
238 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
505 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
265 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

737 
WGUS62 KFFC 211607
FFAFFC

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1107 AM EST SAT JAN 21 2012

GAZ001>005-011-211715-
/O.CAN.KFFC.FA.A.0001.000000T0000Z-120122T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DADE-WALKER-CATOOSA-WHITFIELD-MURRAY-CHATTOOGA-
1107 AM EST SAT JAN 21 2012

...FLOOD WATCH IS CANCELLED...

THE FLOOD WATCH FOR A PORTION OF NORTHWEST GEORGIA HAS BEEN
CANCELLED. THE RAIN HAS TAPERED OFF THIS MORNING AND THE THREAT
FOR HEAVY RAIN AND FLOODING HAS ENDED.

$$

GAZ022-031>035-041>048-052>057-220000-
/O.NEW.KFFC.FF.A.0001.120121T1607Z-120122T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FORSYTH-PAULDING-COBB-NORTH FULTON-GWINNETT-BARROW-HARALSON-
CARROLL-DOUGLAS-SOUTH FULTON-DEKALB-ROCKDALE-WALTON-NEWTON-HEARD-
COWETA-FAYETTE-CLAYTON-SPALDING-HENRY-
INCLUDING THE CITIES OF...MARIETTA...ATLANTA...LAWRENCEVILLE...
CARROLLTON...DOUGLASVILLE...EAST POINT...DECATUR...CONYERS...
COVINGTON...NEWNAN...PEACHTREE CITY...GRIFFIN
1107 AM EST SAT JAN 21 2012

...FLASH FLOOD WATCH IN EFFECT UNTIL 7 PM EST THIS EVENING...

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NORTH CENTRAL GEORGIA... 
  NORTHWEST GEORGIA AND WEST CENTRAL GEORGIA. 

* UNTIL 7 PM EST THIS EVENING

* RAINFALL AMOUNTS OF 1 TO 3 INCHES HAS FALLEN OVER PARTS OF
  WESTCENTRAL GEORGIA AND THE ATLANTA METRO AREA. ANOTHER LINE OF
  SHOWERS AND THUNDERSTORMS IS EXPECTED TO AFFECT MUCH OF THIS
  AREA AGAIN TODAY WITH AN ADDITIONAL 1 TO 3 INCHES OF RAIN
  POSSIBLE. SOME MINOR FLOODING HAS ALREADY BEEN REPORTED.

* HEAVY RAIN WILL CAUSE RAPID RISES AND MINOR FLOODING OF SMALLER
  CREEKS AND STREAMS. ROADWAYS MAY BECOME COVERED WITH FLOWING
  WATER. URBAN AREAS WILL ALSO SEE FLOODING...ESPECIALLY IN POOR
  DRAINAGE AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.
NEVER DRIVE INTO FLOODED AREAS. TURN AROUND AND DONT DROWN.

MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION SHOULD
ADDITIONAL FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
2 follow-up statements
676 
WGUS62 KFFC 211900
FFAFFC

FLOOD WATCH
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
200 PM EST SAT JAN 21 2012

GAZ022-031-032-034-035-041>043-047-212000-
/O.CAN.KFFC.FF.A.0001.000000T0000Z-120122T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FORSYTH-PAULDING-COBB-GWINNETT-BARROW-HARALSON-CARROLL-DOUGLAS-
WALTON-
INCLUDING THE CITIES OF...MARIETTA...LAWRENCEVILLE...CARROLLTON...
DOUGLASVILLE
200 PM EST SAT JAN 21 2012

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTH CENTRAL GEORGIA AND
NORTHWEST GEORGIA HAS BEEN CANCELLED. RAIN HAS TAPERED OFF AND
BASED ON THE AMOUNT OF RANI THAT FELL...THE THREAT FOR FLOODING
HAS DIMINISHED.

$$

GAZ033-044>046-048-052>057-220000-
/O.CON.KFFC.FF.A.0001.000000T0000Z-120122T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORTH FULTON-SOUTH FULTON-DEKALB-ROCKDALE-NEWTON-HEARD-COWETA-
FAYETTE-CLAYTON-SPALDING-HENRY-
INCLUDING THE CITIES OF...ATLANTA...EAST POINT...DECATUR...
CONYERS...COVINGTON...NEWNAN...PEACHTREE CITY...GRIFFIN
200 PM EST SAT JAN 21 2012

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 7 PM EST THIS
EVENING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTH CENTRAL GEORGIA AND WEST CENTRAL GEORGIA.

* UNTIL 7 PM EST THIS EVENING

* RAINFALL AMOUNTS OF 1 TO 4 INCHES HAS FALLEN OVER PARTS OF
  WESTCENTRAL GEORGIA AND THE ATLANTA METRO AREA. AN ADDITIONAL
  ONE HALF TO ONE INCH OF RAIN REMAINS POSSIBLE. EVEN AFTER THE
  RAIN TAPERS OFF...RUNOFF FROM THE PREVIOUS HEAVY RAIN WILL
  CONTINUE TO CAUSE RISES IN CREEKS AND STREAMS. SEVERAL CREEKS
  AND RIVERS ARE ALREADY OUT OF THEIR BANKS.

* HEAVY RAIN WILL CAUSE RAPID RISES AND MINOR FLOODING OF 
  SMALLER CREEKS AND STREAMS. ROADWAYS MAY BECOME COVERED WITH 
  FLOWING WATER. URBAN AREAS WILL ALSO SEE FLOODING... 
  ESPECIALLY IN POOR DRAINAGE AREAS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.
NEVER DRIVE INTO FLOODED AREAS. TURN AROUND AND DONT DROWN. 

NEVER PLAY IN FLOODED AREAS. DRAINAGE PIPES AND WATERWAYS CAN BE
UNDERWATER AND IMPOSSIBLE TO SEE AND COULD CAUSE AN INDIVIDUAL TO
BE TRAPPED QUICKLY.

MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION SHOULD
ADDITIONAL FLASH FLOOD WARNINGS BE ISSUED.

&&

$$
416 
WGUS62 KFFC 211938
FFAFFC

FLOOD WATCH
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
238 PM EST SAT JAN 21 2012

GAZ033-044>046-048-052>057-212045-
/O.CAN.KFFC.FF.A.0001.000000T0000Z-120122T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORTH FULTON-SOUTH FULTON-DEKALB-ROCKDALE-NEWTON-HEARD-COWETA-
FAYETTE-CLAYTON-SPALDING-HENRY-
INCLUDING THE CITIES OF...ATLANTA...EAST POINT...DECATUR...
CONYERS...COVINGTON...NEWNAN...PEACHTREE CITY...GRIFFIN
238 PM EST SAT JAN 21 2012

...FLASH FLOOD WATCH IS CANCELLED...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTH CENTRAL GEORGIA AND
WEST CENTRAL GEORGIA HAS BEEN CANCELLED. RAIN HAS TAPERED OFF AND
BASED ON THE AMOUNT OF RAIN THAT FELL...THE THREAT FOR FLOODING HAS
ENDED.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 21, 7:19 AM ESTSpecial Weather StatementFFCCarroll, Douglas, Fulton41 min
Jan 21, 8:00 AM ESTSpecial Weather StatementFFCCarroll, Douglas, Fulton45 min
Jan 21, 8:18 AM ESTSpecial Weather StatementFFCMurray27 min
Jan 21, 8:43 AM ESTSpecial Weather StatementFFCDouglas, Newton, Rockdale47 min
Jan 21, 8:56 AM ESTSpecial Weather StatementFFCChattooga, Gordon, Murray, Whitfield34 min
Jan 21, 9:27 AM ESTSpecial Weather StatementFFCFannin, Union33 min
Jan 21, 9:47 AM ESTSpecial Weather StatementFFCFloyd43 min
Jan 21, 10:04 AM ESTSpecial Weather StatementFFCCarroll, Douglas, Fulton41 min
Jan 21, 10:19 AM ESTFlash Flood WarningFFCCarroll, Douglas4 hr
Jan 21, 10:22 AM ESTSevere Thunderstorm WarningFFCDeKalb, Fulton38 min
Jan 21, 10:24 AM ESTSpecial Weather StatementFFCDawson36 min
Jan 21, 10:43 AM ESTSpecial Weather StatementFFCForsyth, Hall32 min
Jan 21, 10:50 AM ESTFlash Flood WarningFFCDeKalb, Fulton5 hr
Jan 21, 10:50 AM ESTSpecial Weather StatementFFCDeKalb, Rockdale, Walton40 min
Jan 21, 10:59 AM ESTSevere Thunderstorm WarningFFCHaralson, Paulding46 min
Jan 21, 11:22 AM ESTSevere Thunderstorm WarningFFCCobb, DeKalb, Fulton38 min
Jan 21, 11:27 AM ESTSpecial Weather StatementFFCBanks, Jackson, Madison33 min
Jan 21, 11:28 AM ESTSpecial Weather StatementFFCCarroll, Douglas, Fulton47 min
Jan 21, 11:32 AM ESTSpecial Weather StatementFFCOconee, Walton28 min
Jan 21, 11:32 AM ESTSevere Thunderstorm WarningFFCCarroll, Douglas, Fulton28 min
Jan 21, 11:34 AM ESTTornado WarningFFCCoweta, Heard41 min
Jan 21, 11:44 AM ESTSevere Thunderstorm WarningFFCClarke, Greene, Morgan, Oconee, Oglethorpe, Walton46 min
Jan 21, 11:57 AM ESTSpecial Weather StatementFFCMeriwether, Troup33 min
Jan 21, 12:04 PM ESTFlash Flood WarningFFCClayton2 hr
Jan 21, 12:16 PM ESTTornado WarningFFCCoweta, Fayette28 min
Jan 21, 12:26 PM ESTSevere Thunderstorm WarningFFCLamar, Meriwether, Pike, Upson49 min
Jan 21, 12:29 PM ESTSpecial Weather StatementFFCOglethorpe, Wilkes46 min
Jan 21, 12:38 PM ESTSevere Thunderstorm WarningFFCButts, Clayton, Henry, Spalding52 min
Jan 21, 12:43 PM ESTSpecial Weather StatementFFCMorgan32 min
Jan 21, 1:00 PM ESTSevere Thunderstorm WarningFFCBibb, Jones, Lamar, Monroe, Upson45 min
Jan 21, 1:05 PM ESTSevere Thunderstorm WarningFFCJasper, Newton40 min
Jan 21, 1:11 PM ESTSpecial Weather StatementFFCHarris34 min
Jan 21, 1:20 PM ESTTornado WarningFFCHarris40 min
Jan 21, 1:30 PM ESTSpecial Weather StatementFFCUpson30 min
Jan 21, 1:44 PM ESTSevere Thunderstorm WarningFFCBaldwin, Hancock, Jasper, Jones, Putnam, Washington and 1 more46 min
Jan 21, 1:57 PM ESTTornado WarningFFCTalbot32 min
Jan 21, 1:59 PM ESTSpecial Weather StatementFFCMuscogee31 min
Jan 21, 2:05 PM ESTSevere Thunderstorm WarningFFCHarris, Muscogee25 min
Jan 21, 2:14 PM ESTSevere Thunderstorm WarningFFCUpson34 min
Jan 21, 2:21 PM ESTTornado WarningFFCBaldwin, Hancock, Washington, Wilkinson39 min
Jan 21, 2:27 PM ESTSevere Thunderstorm WarningFFCBibb, Crawford, Peach, Taylor48 min
Jan 21, 2:32 PM ESTSpecial Weather StatementFFCTaylor28 min
Jan 21, 2:59 PM ESTSpecial Weather StatementFFCJefferson, Washington31 min
Jan 21, 2:59 PM ESTSevere Thunderstorm WarningFFCChattahoochee, Marion, Muscogee, Schley46 min
Jan 21, 3:06 PM ESTSevere Thunderstorm WarningFFCMacon, Taylor39 min
Jan 21, 3:07 PM ESTTornado WarningFFCJefferson, Washington38 min
Jan 21, 3:20 PM ESTSpecial Weather StatementFFCBleckley, Houston, Peach, Twiggs25 min
Jan 21, 3:28 PM ESTTornado WarningFFCMacon47 min
Jan 21, 3:53 PM ESTTornado WarningFFCDooly, Houston37 min
Jan 21, 4:00 PM ESTSevere Thunderstorm WarningFFCEmanuel, Johnson60 min
Jan 21, 4:02 PM ESTSevere Thunderstorm WarningFFCChattahoochee, Marion43 min
Jan 21, 4:18 PM ESTSevere Thunderstorm WarningFFCPulaski, Wilcox42 min
Jan 21, 4:27 PM ESTSevere Thunderstorm WarningFFCDooly, Houston18 min
Jan 21, 4:29 PM ESTSpecial Weather StatementFFCStewart31 min
Jan 21, 4:36 PM ESTTornado WarningFFCPulaski24 min
Jan 21, 4:43 PM ESTSevere Thunderstorm WarningFFCStewart, Webster62 min
Jan 21, 4:49 PM ESTSevere Thunderstorm WarningFFCDodge41 min
Jan 21, 4:50 PM ESTSevere Thunderstorm WarningFFCMarion, Schley, Sumter39 min
Jan 21, 5:24 PM ESTSpecial Weather StatementFFCMontgomery, Telfair, Wheeler66 min
Jan 21, 5:27 PM ESTSevere Thunderstorm WarningFFCTelfair, Wheeler48 min
Jan 21, 5:33 PM ESTSevere Thunderstorm WarningFFCDodge, Wilcox15 min
Jan 21, 5:39 PM ESTSpecial Weather StatementFFCCrisp66 min
Jan 21, 5:50 PM ESTSpecial Weather StatementFFCTelfair, Wilcox40 min
Jan 21, 6:12 PM ESTSevere Thunderstorm WarningFFCMontgomery, Toombs, Wheeler33 min

Nearby

Flash Flood Watches in Georgia, 2012Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.