Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 431, NWS Atlanta, GA

July 5, 2011Gwinnett County, Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Jul 5, 2011, 8:55 PM EDT for Gwinnett County, Georgia. It was in force for 41 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: Jul 5, 2011, 8:55 PM EDT (00:55 UTC)
Expired: Jul 5, 2011, 9:36 PM EDT
In force: 41 min
Issued by: NWS Atlanta, GA
Area: Storm-based polygon

County Gwinnett County, GA

The radar

The Atlanta radar (KFFC), 93 km from the middle of the area, began a volume at 00:56 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, 0.9 hours before the alert went out and 89 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: 276 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 1741 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 0 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.

157 
WUUS52 KFFC 060055
SVRFFC
GAC135-060145-
/O.NEW.KFFC.SV.W.0431.110706T0055Z-110706T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
855 PM EDT TUE JUL 5 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN GWINNETT COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 945 PM EDT

* AT 851 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZED
  HAIL...AND DAMAGING WINDS UP TO 60 MPH.  THESE STORMS WERE LOCATED
  BETWEEN SUWANEE AND DULUTH...WITH ANOTHER POSSIBLE SEVERE
  THUNDERSTORM BETWEEN LAWRENCEVILLE AND HARBIN...MOVING NORTHEAST 
  AT 10 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO   
  LAWRENCEVILLE...DACULA...SUGAR HILL...REST HAVEN AND BUFORD
  AND HOG MOUNTAIN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

&&

LAT...LON 3410 8388 3411 8385 3408 8383 3400 8387
      3393 8380 3388 8387 3390 8404 3401 8418
      3403 8416 3405 8410 3407 8412 3415 8409
      3417 8406
TIME...MOT...LOC 0054Z 225DEG 7KT 3400 8406

$$

3 follow-up statements

580 
WWUS52 KFFC 060114
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
914 PM EDT TUE JUL 5 2011

GAC135-060145-
/O.CON.KFFC.SV.W.0431.000000T0000Z-110706T0145Z/
GWINNETT GA-
914 PM EDT TUE JUL 5 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR NORTHEASTERN GWINNETT COUNTY...

AT 910 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZED
HAIL...AND DAMAGING WINDS UP TO 60 MPH. THIS STORM WAS LOCATED NEAR
SUWANEE...MOVING NORTHEAST AT 10 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
HARBIN...DACULA...SUGAR HILL...BUFORD DAM-LAKE LANIER PARKS...HOG
MOUNTAIN...REST HAVEN AND BUFORD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE SEVERE WEATHER THREAT...VERY HEAVY RAINFALL ON 
THE ORDER OF 1.0 TO 2.0 INCHES PER HOUR CAN BE EXPECTED WITH THESE 
THUNDERSTORMS. DOPPLER RADAR ESTIMATES THAT UP TO 2.5 INCHES OF RAIN 
HAS ALREADY FALLEN ACROSS PARTS OF EASTERN GWINNETT COUNTY. 
ADDITIONAL RAINFALL WILL RESULT IN RUNOFF INTO AREA 
CREEKS...STREAMS...AND RIVERS. PONDING OF WATER ON ROADWAYS AND 
FLOODING OF LOW-LYING AND FLOOD PRONE AREAS WILL BE POSSIBLE DURING 
THE NEXT HOUR.

BE ESPECIALLY CAREFUL WHEN DRIVING IN AREAS OF HEAVY RAIN AT NIGHT. 
DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. THE WATER DEPTH 
MAY BE TOO GREAT FOR YOU TO PROCEED SAFELY. TURN AROUND...DON'T 
DROWN!

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL AFTER THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

&&

LAT...LON 3410 8388 3410 8385 3408 8383 3400 8387
      3393 8380 3389 8385 3388 8387 3398 8407
      3405 8410 3407 8412 3414 8409 3417 8406
TIME...MOT...LOC 0112Z 225DEG 7KT 3402 8403

$$



19

920 
WWUS52 KFFC 060115 CCA
SVSFFC

SEVERE WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
914 PM EDT TUE JUL 5 2011

GAC135-060145-
/O.COR.KFFC.SV.W.0431.000000T0000Z-110706T0145Z/
GWINNETT GA-
914 PM EDT TUE JUL 5 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR EASTERN GWINNETT COUNTY...

AT 910 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZED
HAIL...AND DAMAGING WINDS UP TO 60 MPH. THIS STORM WAS LOCATED NEAR
SUWANEE...MOVING NORTHEAST AT 10 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
HARBIN...DACULA...SUGAR HILL...BUFORD DAM-LAKE LANIER PARKS...HOG
MOUNTAIN...REST HAVEN AND BUFORD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE SEVERE WEATHER THREAT...VERY HEAVY RAINFALL ON 
THE ORDER OF 1.0 TO 2.0 INCHES PER HOUR CAN BE EXPECTED WITH THESE 
THUNDERSTORMS. DOPPLER RADAR ESTIMATES THAT UP TO 2.5 INCHES OF RAIN 
HAS ALREADY FALLEN ACROSS PARTS OF EASTERN GWINNETT COUNTY. 
ADDITIONAL RAINFALL WILL RESULT IN RUNOFF INTO AREA 
CREEKS...STREAMS...AND RIVERS. PONDING OF WATER ON ROADWAYS AND 
FLOODING OF LOW-LYING AND FLOOD PRONE AREAS WILL BE POSSIBLE DURING 
THE NEXT HOUR.

BE ESPECIALLY CAREFUL WHEN DRIVING IN AREAS OF HEAVY RAIN AT NIGHT. 
DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. THE WATER DEPTH 
MAY BE TOO GREAT FOR YOU TO PROCEED SAFELY. TURN AROUND...DON'T 
DROWN!

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL AFTER THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

&&

LAT...LON 3410 8388 3410 8385 3408 8383 3400 8387
      3393 8380 3389 8385 3388 8387 3398 8407
      3405 8410 3407 8412 3414 8409 3417 8406
TIME...MOT...LOC 0112Z 225DEG 7KT 3402 8403

$$



19

154 
WWUS52 KFFC 060136
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
936 PM EDT TUE JUL 5 2011

GAC135-060144-
/O.CAN.KFFC.SV.W.0431.000000T0000Z-110706T0145Z/
GWINNETT GA-
936 PM EDT TUE JUL 5 2011

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN GWINNETT COUNTY HAS 
BEEN CANCELLED...

THE THUNDERSTORMS THAT EARLIER PROMPTED THE WARNING FOR EASTERN 
GWINNETT COUNTY HAVE WEAKENED AND ARE NO LONGER EXPECTED TO PRODUCE 
SEVERE WEATHER. HOWEVER...HEAVY RAIN AND OCCASIONAL CLOUD-TO-GROUND 
LIGHTNING WILL CONTINUE ACROSS EASTERN GWINNETT COUNTY THROUGH 100 
PM EDT.

HEAVY RAINFALL...ON THE ORDER OF 2.0 TO 2.5 INCHES HAS FALLEN ACROSS 
MANY PARTS OF EASTERN GWINNETT COUNTY DURING THE PAST COUPLE OF 
HOURS. ADDITIONAL RAINFALL UP TO 0.5 INCH WILL BE POSSIBLE EAST OF 
SUWANEE AND LAWRENCEVILLE DURING THE NEXT 30 MINUTES. MINOR FLOODING 
ON ROADWAYS AND IN LOW-LYING...FLOOD PRONE AREAS WILL REMAIN 
POSSIBLE DURING THE NEXT HOUR. BE ESPECIALLY CAREFUL WHEN DRIVING IN 
AREAS OF HEAVY RAIN AT NIGHT. DO NOT DRIVE INTO AREAS WHERE WATER 
COVERS THE ROAD. THE WATER DEPTH MAY BE TOO GREAT FOR YOU TO PROCEED 
SAFELY. TURN AROUND...DON'T DROWN!

IF YOU SEE WIND DAMAGE...LARGE HAIL OR SIGNIFICANT FLOODING...WAIT
UNTIL AFTER THE STORM HAS PASSED...AND THEN CALL THE NATIONAL WEATHER
SERVICE TOLL FREE AT 1 8 6 6 7 6 3 4 4 6 6.

LAT...LON 3410 8388 3410 8385 3408 8383 3400 8387
      3393 8380 3389 8385 3388 8387 3398 8407
      3405 8410 3407 8412 3414 8409 3417 8406
TIME...MOT...LOC 0134Z 225DEG 7KT 3405 8399

$$



19

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 8:32 PM EDT	Special Weather Statement	FFC	Hall	43 min
Jul 5, 8:43 PM EDT	Special Weather Statement	FFC	Gwinnett	32 min
Jul 5, 9:03 PM EDT	Special Weather Statement	FFC	Polk	27 min
Jul 5, 10:32 PM EDT	Special Weather Statement	FFC	Douglas, Paulding	28 min
Jul 5, 11:02 PM EDT	Special Weather Statement	FFC	Cobb	43 min
Jul 6, 1:30 PM EDT	Special Weather Statement	FFC	Newton, Rockdale	45 min
Jul 6, 2:03 PM EDT	Special Weather Statement	FFC	Oglethorpe	27 min
Jul 6, 3:24 PM EDT	Special Weather Statement	FFC	Houston, Peach	36 min
Jul 6, 3:44 PM EDT	Special Weather Statement	FFC	Walker	31 min
Jul 6, 3:47 PM EDT	Special Weather Statement	FFC	Emanuel	28 min
Jul 6, 4:42 PM EDT	Special Weather Statement	FFC	Laurens	48 min
Jul 6, 5:24 PM EDT	Special Weather Statement	FFC	Montgomery, Toombs	51 min
Jul 6, 5:32 PM EDT	Special Weather Statement	FFC	Emanuel	28 min
Jul 6, 6:12 PM EDT	Special Weather Statement	FFC	Candler	33 min
Jul 6, 7:59 PM EDT	Special Weather Statement	FFC	Putnam	31 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2011 Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.