Alert archive / Georgia / Flash Flood Warnings in 2012

Flash Flood Warning 15, NWS Atlanta, GA

July 11, 2012Cobb County, Georgia

NWS Atlanta, GA issued this flash flood warning at Jul 11, 2012, 11:50 PM EDT for Cobb 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: Jul 11, 2012, 11:50 PM EDT (03:50 UTC)
Expired: Jul 12, 2012, 5:45 AM EDT
In force: 6 hr
Issued by: NWS Atlanta, GA
Area: Storm-based polygon
Flood severity: None

County Cobb County, GA

The radar

The Atlanta radar (KFFC), 72 km from the middle of the area, began a volume at 03:52 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
Jul 12, 12:10 AM EDT	FLASH FLOOD	6 E Marietta, GA	THE WATER LEVEL AT A USGS STREAM GAGE ON THE SOPE CREEK AT LOWER ROSWELL ROAD REACHED FLOOD STAGE OF 12 FEET.
Jul 12, 12:40 AM EDT	FLASH FLOOD	6 Ene Marietta, GA	THE WATER LEVEL AT A USGS STREAM GAGE ON THE SEWELL MILL CREEK AT ROSWELL ROAD REACHED FLOOD STAGE OF 12 FEET.

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, 3.8 hours before the alert went out and 71 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: 564 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1486 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 47 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.

628 
WGUS52 KFFC 120350
FFWFFC
GAC067-120945-
/O.NEW.KFFC.FF.W.0015.120712T0350Z-120712T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1150 PM EDT WED JUL 11 2012

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN COBB COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 545 AM EDT THURSDAY

* AT 1138 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  POTENTIAL FLASH FLOODING FROM THUNDERSTORMS OVER THE WARNED AREA.
  RAINFALL AMOUNTS OF 2 TO 3 INCHES HAVE OCCURRED SINCE 930 PM EDT
  OVER THE SEWELL MILL CREEK BASIN. ANOTHER INCH IS POSSIBLE BEFORE
  THE RAIN MOVES OUT OF THE WARNED AREA BY 100 AM EDT ON THURSDAY    
  MORNING.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SWEAT
  MOUNTAIN AND SANDY PLAINS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HIGH WATER IS MOVING DOWN THE SEWELL MILL CREEK. THE USGS GAGE ON 
ROSWELL ROAD WAS AT 7.3 FEET AND RISING AT 1130 PM EDT. FLOOD STAGE 
IS 12 FEET. THE CREEK IS EXPECTED TO REACH OR EXCEED FLOOD STAGE 
LATER TONIGHT...THEN FALL RAPIDLY BY SUNRISE ON THURSDAY.

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. YOU CAN ALSO TWEET YOUR REPORT
USING HASHTAG GAWX.

&&

LAT...LON 3408 8458 3407 8442 3404 8440 3401 8440
      3398 8437 3396 8439 3391 8445 3390 8458

$$

16

4 follow-up statements

229 
WGUS72 KFFC 120455
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1255 AM EDT THU JUL 12 2012

GAC067-120945-
/O.CON.KFFC.FF.W.0015.000000T0000Z-120712T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COBB GA-
1255 AM EDT THU JUL 12 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM EDT FOR
NORTHEASTERN COBB COUNTY...

AT 1245 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE LIGHT RAIN OVER THE WARNED AREA. FLASH FLOODING WAS 
OCCURRING IN THE SEWELL MILL CREEK AND SOPE CREEK BASINS. RAINFALL
AMOUNTS OF 4 TO 6 INCHES HAS OCCURRED BETWEEN SANDY PLAINS AND
MOUNT BETHEL OF NORTHEAST COBB COUNTY SINCE 930 PM EDT WEDNESDAY 
EVENING. 

AT 1230 AM EDT...THE SEWELL MILL CREEK AT ROSWELL ROAD WAS AT 11.8 
FEET AND RISING. FLOOD STAGE IS 12 FEET. THE CREEK SHOULD CREST 
AROUND 13 FEET EARLY THIS MORNING BEFORE FALLING RAPIDLY BY SUNRISE. 
PORTIONS OF THE EAST COBB PARK WILL BE FLOODED.

AT 1230 AM EDT...THE SOPE CREEK NEAR MARIETTA WAS AT 13.1 FEET AND 
RISING. FLOOD STAGE IS 12 FEET. THE CREEK SHOULD CREST AROUND 14 
FEET EARLY THIS MORNING BEFORE FALLING RAPIDLY BY SUNRISE. YARDS OF 
HOMES NEAR LOWER ROSWELL ROAD WILL BE FLOODED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU SEE SIGNIFICANT FLOODING CALL THE NATIONAL WEATHER SERVICE
TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6. YOU CAN ALSO TWEET YOUR REPORT
USING HASHTAG GAWX.

&&

LAT...LON 3408 8458 3407 8442 3404 8440 3401 8440
      3398 8437 3396 8439 3391 8445 3390 8458

$$

16

866 
WGUS72 KFFC 120647
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
247 AM EDT THU JUL 12 2012

GAC067-120945-
/O.CON.KFFC.FF.W.0015.000000T0000Z-120712T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COBB GA-
247 AM EDT THU JUL 12 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM EDT FOR
NORTHEASTERN COBB COUNTY...

...SIGNIFICANT FLOODING EXPECTED ALONG SOPE CREEK NEAR MARIETTA...

AT 235 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
LIGHT RAIN ENDING OVER THE WARNED AREA. FLASH FLOODING CONTINUED ON
THE SOPE CREEK FROM SOUTH OF ROSWELL ROAD THROUGH THE INDIAN HILLS 
AREA TO PAPER MILL ROAD. THE FLOOD WATER WAS FLOWING INTO THE 
CHATTAHOOCHEE RIVER. THE FLASH FLOODING WAS A RESULT OF 4 TO 6 
INCHES OF RAIN THAT OCCURRED BETWEEN SANDY PLAINS AND MOUNT BETHEL 
OF NORTHEAST COBB COUNTY ON WEDNESDAY EVENING. 

AT 215 AM EDT...THE SOPE CREEK NEAR MARIETTA WAS AT 14.9 FEET AND 
RISING. FLOOD STAGE IS 12 FEET. THE CREEK SHOULD CREST AROUND 15.5 
FEET EARLY THIS MORNING BEFORE FALLING RAPIDLY BY SUNRISE. 
SIGNIFICANT FLOODING OF YARDS OF HOMES NEAR LOWER ROSWELL ROAD...THE 
INDIANS HILLS AREA...AND THE INDIAN HILLS GOLF COURSE WILL OCCUR.

AT 230 AM EDT...THE SEWELL MILL CREEK AT ROSWELL ROAD WAS AT 10.8  
FEET AND FALLING. FLOOD STAGE IS 12 FEET. THE CREEK CREST AT 12.2 
FEET AT 100 AM EDT. PORTIONS OF THE EAST COBB PARK HAVE FLOODED. THE 
CREEK WILL CONTINUE TO FALL THROUGH THE MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. YOU CAN ALSO TWEET YOUR REPORT
USING HASHTAG GAWX.

&&

LAT...LON 3408 8458 3407 8442 3404 8440 3401 8440
      3398 8437 3396 8439 3391 8445 3390 8458

$$

16

447 
WGUS72 KFFC 120805
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
405 AM EDT THU JUL 12 2012

GAC067-120945-
/O.CON.KFFC.FF.W.0015.000000T0000Z-120712T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COBB GA-
405 AM EDT THU JUL 12 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM EDT FOR
NORTHEASTERN COBB COUNTY...

...SIGNIFICANT FLOODING OCCURS ALONG SOPE CREEK NEAR MARIETTA...

AT 355 AM EDT...FLASH FLOODING CONTINUED ON THE SOPE CREEK FROM THE 
INDIAN HILLS AREA TO COLUMNS DRIVE. THE FLOOD WATER WAS FLOWING INTO 
THE CHATTAHOOCHEE RIVER.  

AT 345 AM EDT...THE SOPE CREEK NEAR MARIETTA WAS AT 15.5 FEET AND 
BEGINNING TO FALL. FLOOD STAGE IS 12 FEET. THE CREEK CREST AT 15.7 
FEET AROUND 300 AM EDT EARLIER THIS MORNING. THE CREEK SHOULD FALL 
BELOW FLOOD STAGE BY 600 AM EDT. 

SIGNIFICANT FLOODING OF YARDS OF HOMES NEAR LOWER ROSWELL ROAD...
THE INDIANS HILLS AREA...AND THE INDIAN HILLS GOLF COURSE HAS BEEN 
OCCURRING. COBB COUNTY PATROL OFFICERS INDICATE THE WATER LEVEL OF 
THE CREEK HAS REACHED THE BOTTOM OF THE COLUMNS DRIVE BRIDGE. 
CONDITIONS WILL IMPROVE OVER THE NEXT FEW HOURS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY...THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE 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. YOU CAN ALSO TWEET YOUR REPORT
USING HASHTAG GAWX.

&&

LAT...LON 3408 8458 3407 8442 3404 8440 3401 8440
      3398 8437 3396 8439 3391 8445 3390 8458

$$

16

212 
WGUS72 KFFC 120937
FFSFFC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
537 AM EDT THU JUL 12 2012

GAC067-120945-
/O.CON.KFFC.FF.W.0015.000000T0000Z-120712T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COBB GA-
537 AM EDT THU JUL 12 2012

...A FLASH FLOOD WARNING WILL EXPIRE AT 545 AM EDT FOR NORTHEASTERN 
COBB COUNTY...

AT 530 AM EDT...ONLY LIGHT RAIN WAS REPORTED OVER THE WARNED AREA.
FLASH FLOODING HAD DIMINISHED ON THE SOPE CREEK FROM THE INDIAN 
HILLS AREA TO COLUMNS DRIVE. THE FLOOD WATER WAS FLOWING INTO THE 
CHATTAHOOCHEE RIVER. 

AT 515 AM EDT...THE SOPE CREEK NEAR MARIETTA WAS AT 12 FEET AND 
FALLING RAPIDLY. FLOOD STAGE IS 12 FEET. THE CREEK CRESTED AT 15.7 
FEET AROUND 300 AM EDT EARLIER THIS MORNING. THE CREEK SHOULD FALL 
BELOW FLOOD STAGE BY 600 AM EDT. 

SIGNIFICANT FLOODING OF YARDS OF HOMES NEAR LOWER ROSWELL ROAD...THE 
INDIANS HILLS AREA...AND THE INDIAN HILLS GOLF COURSE HAD OCCURRED.  
COBB COUNTY PATROL OFFICERS INDICATE THE WATER LEVEL OF THE CREEK 
HAD REACHED THE BOTTOM OF THE COLUMNS DRIVE BRIDGE. CONDITIONS WILL 
IMPROVE OVER THE NEXT FEW HOURS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY...THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE 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. YOU CAN ALSO TWEET YOUR REPORT
USING HASHTAG GAWX.

&&

LAT...LON 3408 8458 3407 8442 3404 8440 3401 8440
      3398 8437 3396 8439 3391 8445 3390 8458

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 8:33 PM EDT	Special Weather Statement	FFC	Greene	27 min
Jul 11, 9:14 PM EDT	Special Weather Statement	FFC	Baldwin	31 min
Jul 11, 9:32 PM EDT	Special Weather Statement	FFC	Cobb	28 min
Jul 11, 9:38 PM EDT	Special Weather Statement	FFC	Cobb	22 min
Jul 11, 9:39 PM EDT	Severe Thunderstorm Warning	FFC	Cobb	39 min
Jul 11, 9:56 PM EDT	Special Weather Statement	FFC	Clayton	34 min
Jul 11, 11:33 PM EDT	Special Weather Statement	FFC	Cobb	42 min
Jul 12, 3:59 PM EDT	Special Weather Statement	FFC	Emanuel	31 min
Jul 12, 5:08 PM EDT	Special Weather Statement	FFC	Johnson	22 min
Jul 12, 5:50 PM EDT	Special Weather Statement	FFC	Floyd	25 min
Jul 12, 6:25 PM EDT	Special Weather Statement	FFC	Putnam	35 min
Jul 12, 6:37 PM EDT	Special Weather Statement	FFC	Floyd	23 min
Jul 12, 6:59 PM EDT	Special Weather Statement	FFC	Carroll, Heard, Troup	46 min
Jul 12, 7:01 PM EDT	Special Weather Statement	FFC	Haralson	29 min

Nearby

Flash Flood Warnings in Georgia, 2012 Every flash flood warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.