Alert archive / Georgia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 183, NWS Atlanta, GA

April 20, 20118 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Apr 20, 2011, 7:39 AM EDT for 8 counties in Georgia. It was in force for 51 min. 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
Apr 20, 2011, 7:39 AM EDT (11:39 UTC)
Expired
Apr 20, 2011, 8:30 AM EDT
In force
51 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon

Counties Catoosa County, GA, Chattooga County, GA, Dade County, GA, Floyd County, GA, Gordon County, GA, Murray County, GA, Walker County, GA, Whitfield County, GA

The radar

The Northeast Alabama radar (KHTX), 78 km from the middle of the area, began a volume at 11:40 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

TimeReportWhereRemark
Apr 20, 7:54 AM EDTTSTM WND DMG3 Ese Cedar Grove, GAWALKER COUNTY 911 RELAYED A REPORT OF TWO TREES DOWN ESE OF CEDAR GROVE.
Apr 20, 7:55 AM EDTHAIL 0.25Tunnel Hill, GA

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, 11.7 hours before the alert went out and 165 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 2011-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3375 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
97 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.

301 
WUUS52 KFFC 201139
SVRFFC
GAC047-055-083-115-129-213-295-313-201230-
/O.NEW.KFFC.SV.W.0183.110420T1139Z-110420T1230Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
739 AM EDT WED APR 20 2011

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CATOOSA COUNTY IN NORTHWEST GEORGIA
  CHATTOOGA COUNTY IN NORTHWEST GEORGIA
  DADE COUNTY IN NORTHWEST GEORGIA
  NORTHERN FLOYD COUNTY IN NORTHWEST GEORGIA
  WESTERN GORDON COUNTY IN NORTHWEST GEORGIA
  WEST CENTRAL MURRAY COUNTY IN NORTHWEST GEORGIA
  WALKER COUNTY IN NORTHWEST GEORGIA
  WHITFIELD COUNTY IN NORTHWEST GEORGIA

* UNTIL 830 AM EDT

* AT 736 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZED
  HAIL...AND DAMAGING WINDS UP TO 60 MPH.  THESE STORMS WERE LOCATED
  ALONG A LINE EXTENDING FROM 5 MILES NORTHWEST OF TRENTON TO 20
  MILES SOUTHWEST OF TRENTON TO 30 MILES WEST OF SUMMERVILLE...MOVING
  EAST AT 45 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  LOOKOUT MOUNTAIN...FORT OGLETHORPE...CHICKAMAUGA...LAFAYETTE...
  RINGGOLD...TRION...TUNNEL HILL...VARNELL...COHUTTA...DALTON AND
  ROME.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3499 8517 3496 8483 3472 8492 3460 8501
      3421 8511 3428 8547 3429 8547 3486 8559
      3495 8561 3499 8560
TIME...MOT...LOC 1138Z 275DEG 41KT 3494 8557 3466 8577
          3445 8586

$$
1 follow-up statement
698 
WWUS52 KFFC 201222
SVSFFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
822 AM EDT WED APR 20 2011

GAC083-201232-
/O.CAN.KFFC.SV.W.0183.000000T0000Z-110420T1230Z/
DADE GA-
822 AM EDT WED APR 20 2011

...THE SEVERE THUNDERSTORM WARNING FOR DADE COUNTY IS CANCELLED...


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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL NOON EDT
WEDNESDAY FOR NORTHERN GEORGIA.

LAT...LON 3426 8524 3432 8523 3481 8526 3490 8523
      3497 8521 3499 8517 3496 8483 3472 8492
      3460 8501 3421 8511
TIME...MOT...LOC 1222Z 275DEG 41KT 3489 8496 3461 8516
          3440 8525

$$

GAC047-055-115-129-213-295-313-201230-
/O.CON.KFFC.SV.W.0183.000000T0000Z-110420T1230Z/
WHITFIELD GA-WALKER GA-MURRAY GA-CATOOSA GA-CHATTOOGA GA-FLOYD GA-
GORDON GA-
822 AM EDT WED APR 20 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 AM EDT
FOR WESTERN GORDON...CENTRAL FLOYD...NORTHEASTERN CHATTOOGA...
CATOOSA...EXTREME WEST CENTRAL MURRAY...EASTERN WALKER AND WHITFIELD
COUNTIES...

AT 821 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS UP TO 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM VARNELL TO SUTTLES MILL TO ARMUCHEE...MOVING EAST AT 45 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MILL
CREEK...ROME...DALTON...EVERETT SPRINGS...LAKE MARVIN AND BEAVERDALE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL NOON EDT
WEDNESDAY FOR NORTHERN GEORGIA.

&&

LAT...LON 3426 8524 3432 8523 3481 8526 3490 8523
      3497 8521 3499 8517 3496 8483 3472 8492
      3460 8501 3421 8511
TIME...MOT...LOC 1222Z 275DEG 41KT 3489 8496 3461 8516
          3440 8525

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 20, 8:15 AM EDTSevere Thunderstorm WarningFFCFannin, Gilmer, Gordon, Murray, Pickens, Whitfield45 min
Apr 20, 8:18 AM EDTFlash Flood WarningFFCWhitfield116 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2011Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.