Alert archive / Georgia / Flash Flood Watches in 2021

Flash Flood Watch 9, NWS Atlanta, GA

July 20, 202145 counties in Georgia

NWS Atlanta, GA issued this flash flood watch at Jul 20, 2021, 3:21 AM EDT for 45 counties in Georgia. It took effect at Jul 20, 2021, 4:00 AM EDT. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued
Jul 20, 2021, 3:21 AM EDT (07:21 UTC)
In effect from
Jul 20, 2021, 4:00 AM EDT
Expired
Jul 20, 2021, 10:00 PM EDT
In force
18 hr
Issued by
NWS Atlanta, GA
Flood severity
None
All 45 counties

Banks County, GA, Barrow County, GA, Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Hall County, GA, Haralson County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Lumpkin County, GA, Madison County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rockdale County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA

The radar

The Atlanta radar (KFFC), 88 km from the middle of the area, began a volume at 07:25 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, 7.4 hours before the alert went out and 87 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 2021-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 569 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 2021-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
569 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
673 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

494 
WGUS62 KFFC 200721
FFAFFC

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Peachtree City GA
321 AM EDT Tue Jul 20 2021

GAZ008-009-015-016-023>025-027-210000-
/O.NEW.KFFC.FF.A.0009.210720T0800Z-210721T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Union-Towns-Lumpkin-White-Hall-Banks-Jackson-Madison-
Including the cities of , Dahlonega, Gainesville, and Cleveland
321 AM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

The National Weather Service in Peachtree City has issued a

* Flash Flood Watch for portions of north central Georgia and 
  northeast Georgia, including the following areas, in north central 
  Georgia, Hall, Lumpkin and Union. In northeast Georgia, Banks, 
  Jackson, Madison, Towns and White.

* Through this evening.

* A stationary front draped across the area will brings periods of 
  moderate to heavy rainfall across portions of northeast Georgia 
  through this evening. New rainfall amounts of 1 to 2 are possible, 
  with locally higher amounts. This area has recently received 
  between 1 to 2 inches of rain with locally higher amounts of 2.5+ 
  inches. With already saturated soils, quickly accumulating 
  rainfall will easily allow for efficient runoff and increase flash 
  flood potential.

* Creeks and streams may rise out of their banks and inundate 
  fields, roads, businesses and other property. Street flooding 
  could also lead to road closures.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$
4 follow-up statements
944 
WGUS62 KFFC 201402
FFAFFC

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Peachtree City GA
1002 AM EDT Tue Jul 20 2021

GAZ001>007-011>014-019>022-030>035-037-038-041>049-052>055-057-
202215-
/O.EXB.KFFC.FF.A.0009.000000T0000Z-210721T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dade-Walker-Catoosa-Whitfield-Murray-Fannin-Gilmer-Chattooga-Gordon-
Pickens-Dawson-Floyd-Bartow-Cherokee-Forsyth-Polk-Paulding-Cobb-
North Fulton-Gwinnett-Barrow-Oconee-Oglethorpe-Haralson-Carroll-
Douglas-South Fulton-DeKalb-Rockdale-Walton-Newton-Morgan-Heard-
Coweta-Fayette-Clayton-Henry-
Including the cities of , Lawrenceville, Cartersville, Newnan, 
Calhoun, East Point, Conyers, Rome, Marietta, Carrollton, Covington, 
Atlanta, Douglasville, Decatur, and Peachtree City
1002 AM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH 10 PM THIS EVENING...

The National Weather Service in Peachtree City has expanded the

* Flash Flood Watch for much of north and west-central Georgia, 
  including the following counties, Barrow, Cherokee, Clayton, Cobb, 
  Dawson, DeKalb, Douglas, Fannin, Fayette, Forsyth, Gilmer, 
  Gwinnett, Henry, Morgan, Newton, Fulton, Pickens, Rockdale, 
  Walton, Oconee, Oglethorpe, Bartow, Carroll, Catoosa, Chattooga, 
  Dade, Floyd, Gordon, Haralson, Murray, Paulding, Polk, Walker and 
  Whitfield, Coweta and Heard.

* Until 10 PM EDT this evening.

* A stationary front draped across the area will brings periods of 
  moderate to locally heavy rainfall through this evening. New 
  rainfall amounts of 1 to 2 are possible, with locally higher 
  amounts. This area has recently received between 1.5 to 4 inches 
  of rain, with locally higher amounts of up to 5 inches, since 
  Monday morning. With already saturated soils, quickly accumulating 
  rainfall could easily allow for efficient runoff and an increase 
  in flash flood potential, especially along creeks, streams, 
  low-lying and poor drainage areas.

* Fast-responding creeks and streams may rise out of their banks and 
  inundate fields, roads, businesses and other property. Street 
  flooding from persistent heavy rain could quickly lead to 
  problems, especially in urban areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

GAZ008-009-015-016-023>025-027-202215-
/O.EXT.KFFC.FF.A.0009.000000T0000Z-210721T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Union-Towns-Lumpkin-White-Hall-Banks-Jackson-Madison-
Including the cities of , Dahlonega, Gainesville, and Cleveland
1002 AM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH 10 PM THIS EVENING...

The Flash Flood Watch is now in effect for

* Portions of north central and northeast Georgia, including the 
  following counties, Hall, Lumpkin, Union, Banks, Jackson, Madison, 
  Towns and White.

* Until 10 PM EDT this evening.

* A stationary front draped across the area will brings periods of 
  moderate to locally heavy rainfall through this evening. New 
  rainfall amounts of 1 to 2 are possible, with locally higher 
  amounts. This area has recently received between 1.5 to 4 inches 
  of rain, with locally higher amounts of up to 5 inches, since 
  Monday morning. With already saturated soils, quickly accumulating 
  rainfall could easily allow for efficient runoff and an increase 
  in flash flood potential, especially along creeks, streams, 
  low-lying and poor drainage areas.

* Fast-responding creeks and streams may rise out of their banks and 
  inundate fields, roads, businesses and other property. Street 
  flooding from persistent heavy rain could quickly lead to 
  problems, especially in urban areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued. If you encounter running 
water over roadways, find an alternate route and remember to turn 
around don't drown!

&&

$$

DJN
217 
WGUS62 KFFC 201409
FFAFFC

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Peachtree City GA
1009 AM EDT Tue Jul 20 2021

GAZ036-202215-
/O.EXA.KFFC.FF.A.0009.000000T0000Z-210721T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clarke-
Including the cities of Athens
1009 AM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH IN EFFECT UNTIL 10 PM EDT THIS EVENING...

The National Weather Service in Peachtree City has expanded the

* Flash Flood Watch to include Clarke County.

* Until 10 PM EDT this evening.

* A stationary front draped across the area will brings periods of 
  moderate to locally heavy rainfall through this evening. New 
  rainfall amounts of 1 to 2 are possible, with locally higher 
  amounts. This area has recently received between 1 and 3 inches of 
  rain, since Monday morning. With already saturated soils, quickly 
  accumulating rainfall could easily allow for efficient runoff and 
  an increase in flash flood potential, especially along creeks, 
  streams, low-lying and poor drainage areas.

* Fast-responding creeks and streams may rise out of their banks and 
  inundate fields, roads, businesses and other property. Street 
  flooding from persistent heavy rain could quickly lead to 
  problems, especially in urban areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued. If you encounter running 
water over roadways, find an alternate route and remember to turn 
around don't drown!

&&

$$

GAZ001>009-011>016-019>025-027-030>035-037-038-041>049-052>055-057-
202215-
/O.CON.KFFC.FF.A.0009.000000T0000Z-210721T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dade-Walker-Catoosa-Whitfield-Murray-Fannin-Gilmer-Union-Towns-
Chattooga-Gordon-Pickens-Dawson-Lumpkin-White-Floyd-Bartow-Cherokee-
Forsyth-Hall-Banks-Jackson-Madison-Polk-Paulding-Cobb-North Fulton-
Gwinnett-Barrow-Oconee-Oglethorpe-Haralson-Carroll-Douglas-South
Fulton-DeKalb-Rockdale-Walton-Newton-Morgan-Heard-Coweta-Fayette-
Clayton-Henry-
Including the cities of , Conyers, Lawrenceville, Decatur, 
Dahlonega, Newnan, Gainesville, Calhoun, East Point, Marietta, 
Covington, Rome, Carrollton, Cleveland, Atlanta, Douglasville, 
Cartersville, and Peachtree City
1009 AM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM EDT THIS 
EVENING...

The Flash Flood Watch continues for

* Much of north and west central Georgia.

* Until 10 PM EDT this evening.

* A stationary front draped across the area will brings periods of 
  moderate to locally heavy rainfall through this evening. New 
  rainfall amounts of 1 to 2 are possible, with locally higher 
  amounts. This area has recently received between 1.5 to 4 inches 
  of rain, with locally higher amounts of up to 5 inches, since 
  Monday morning. With already saturated soils, quickly accumulating 
  rainfall could easily allow for efficient runoff and an increase 
  in flash flood potential, especially along creeks, streams, 
  low-lying and poor drainage areas.

* Fast-responding creeks and streams may rise out of their banks and 
  inundate fields, roads, businesses and other property. Street 
  flooding from persistent heavy rain could quickly lead to 
  problems, especially in urban areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued. If you encounter running 
water over roadways, find an alternate route and remember to turn 
around don't drown!

&&

$$

DJN
660 
WGUS62 KFFC 201823
FFAFFC

Flood Watch
National Weather Service Peachtree City GA
223 PM EDT Tue Jul 20 2021

GAZ001>009-011>016-019>025-027-030>038-041>049-052>055-057-210200-
/O.CON.KFFC.FF.A.0009.000000T0000Z-210721T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dade-Walker-Catoosa-Whitfield-Murray-Fannin-Gilmer-Union-Towns-
Chattooga-Gordon-Pickens-Dawson-Lumpkin-White-Floyd-Bartow-Cherokee-
Forsyth-Hall-Banks-Jackson-Madison-Polk-Paulding-Cobb-North Fulton-
Gwinnett-Barrow-Clarke-Oconee-Oglethorpe-Haralson-Carroll-Douglas-
South Fulton-DeKalb-Rockdale-Walton-Newton-Morgan-Heard-Coweta-
Fayette-Clayton-Henry-
Including the cities of , East Point, Conyers, Lawrenceville, 
Decatur, Dahlonega, Newnan, Gainesville, Calhoun, Athens, Marietta, 
Covington, Rome, Carrollton, Cleveland, Atlanta, Douglasville, 
Cartersville, and Peachtree City
223 PM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM EDT THIS 
EVENING...

The Flash Flood Watch continues for

* Much of north and west-central Georgia.

* Until 10 PM EDT this evening.

* A stationary front draped across the area will brings periods of 
  moderate to locally heavy rainfall through this evening. New 
  rainfall amounts of 1 to 2 are possible, with locally higher 
  amounts. This area has recently received between 1.5 to 4 inches 
  of rain, with locally higher amounts of up to 5 inches, since 
  Monday morning. With already saturated soils, quickly accumulating 
  rainfall could easily allow for efficient runoff and an increase 
  in flash flood potential, especially along creeks, streams, 
  low-lying and poor drainage areas.

* Fast-responding creeks and streams may rise out of their banks and 
  inundate fields, roads, businesses and other property. Street 
  flooding from persistent heavy rain could quickly lead to 
  problems, especially in urban areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued. If you encounter running 
water over roadways, find an alternate route and remember to turn 
around don't drown!

&&

$$

DJN
295 
WGUS62 KFFC 210211
FFAFFC

Flood Watch
National Weather Service Peachtree City GA
1011 PM EDT Tue Jul 20 2021

GAZ001>009-011>016-019>025-027-030>038-041>049-052>055-057-210315-
/O.EXP.KFFC.FF.A.0009.000000T0000Z-210721T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dade-Walker-Catoosa-Whitfield-Murray-Fannin-Gilmer-Union-Towns-
Chattooga-Gordon-Pickens-Dawson-Lumpkin-White-Floyd-Bartow-Cherokee-
Forsyth-Hall-Banks-Jackson-Madison-Polk-Paulding-Cobb-North Fulton-
Gwinnett-Barrow-Clarke-Oconee-Oglethorpe-Haralson-Carroll-Douglas-
South Fulton-DeKalb-Rockdale-Walton-Newton-Morgan-Heard-Coweta-
Fayette-Clayton-Henry-
Including the cities of , East Point, Conyers, Lawrenceville, 
Decatur, Dahlonega, Newnan, Gainesville, Calhoun, Athens, Marietta, 
Covington, Rome, Carrollton, Cleveland, Atlanta, Douglasville, 
Cartersville, and Peachtree City
1011 PM EDT Tue Jul 20 2021

...FLASH FLOOD WATCH HAS EXPIRED...

The Flash Flood Watch for portions of north central Georgia, 
northeast Georgia, northwest Georgia and west central Georgia, 
including the following areas, in north central Georgia, Barrow, 
Cherokee, Clayton, Cobb, Dawson, DeKalb, Douglas, Fannin, Fayette, 
Forsyth, Gilmer, Gwinnett, Hall, Henry, Lumpkin, Morgan, Newton, 
North Fulton, Pickens, Rockdale, South Fulton, Union and Walton. In 
northeast Georgia, Banks, Clarke, Jackson, Madison, Oconee, 
Oglethorpe, Towns and White. In northwest Georgia, Bartow, Carroll, 
Catoosa, Chattooga, Dade, Floyd, Gordon, Haralson, Murray, Paulding, 
Polk, Walker and Whitfield. In west central Georgia, Coweta and 
Heard has expired.

The Flash Flood Watch is cancelled. Flooding is no longer expected 
to pose a threat across the majority of the area. A couple Flash 
Flood Warnings remain across western Georgia. Although the rain has 
ended, there may still be some residual instances of flooding. 
Please continue to heed remaining road closures.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 9:37 PM EDTSpecial Weather StatementFFCCoweta53 min
Jul 19, 10:07 PM EDTFlash Flood WarningFFCCoweta, Heard, Troup6 hr
Jul 19, 10:13 PM EDTFlash Flood WarningFFCClayton, DeKalb, Fulton6 hr
Jul 19, 10:22 PM EDTRiver Flood WarningFFCDeKalb4 hr
Jul 19, 10:31 PM EDTRiver Flood WarningFFCDeKalb2 hr
Jul 19, 11:09 PM EDTRiver Flood WarningFFCDeKalb98 min
Jul 20, 1:45 PM EDTSpecial Weather StatementFFCHancock30 min
Jul 20, 3:54 PM EDTSpecial Weather StatementFFCNewton36 min
Jul 20, 4:22 PM EDTSpecial Weather StatementFFCMorgan23 min
Jul 20, 5:01 PM EDTSpecial Weather StatementFFCWilkes44 min
Jul 20, 5:40 PM EDTSpecial Weather StatementFFCMeriwether, Troup35 min
Jul 20, 5:55 PM EDTSpecial Weather StatementFFCBibb35 min
Jul 20, 7:17 PM EDTFlash Flood WarningFFCCarroll, Haralson6 hr
Jul 20, 7:41 PM EDTSpecial Weather StatementFFCLamar, Pike49 min
Jul 20, 7:57 PM EDTSpecial Weather StatementFFCJohnson48 min

Nearby

Flash Flood Watches in Georgia, 2021Every flash flood watch in 2021

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.