Alert archive / Georgia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 79, NWS Atlanta, GA

March 21, 20179 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Mar 21, 2017, 8:14 PM EDT for 9 counties in Georgia. It was in force for 46 min. 14 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
Mar 21, 2017, 8:14 PM EDT (00:14 UTC)
Expired
Mar 21, 2017, 9:00 PM EDT
In force
46 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Bartow County, GA, Cherokee County, GA, Cobb County, GA, Dawson County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Paulding County, GA, Polk County, GA

The radar

The Atlanta radar (KFFC), 96 km from the middle of the area, began a volume at 00:16 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
Mar 21, 8:15 PM EDTTSTM WND DMGBall Ground, GATREE DOWN NEAR THE INTERSECTION OF CANTON HWY AND MINERAL SPRINGS ROAD CAUSING A 2 CAR ACCIDENT
Mar 21, 8:15 PM EDTTSTM WND DMGHabersham, GATREES DOWNED...SNAPPED ALONG SEMINOLA ROAD NEAR CARTERSVILLE
Mar 21, 8:16 PM EDTTSTM WND DMG2 Se Gober, GASEVERAL TREES DOWN BLOCKING THE ROAD
Mar 21, 8:20 PM EDTTSTM WND DMG1 Wsw Buffington, GA*** 1 INJ *** TREE AND POWERLINES DOWN IN ROADWAY CAUSING A CAR ACCIDENT
Mar 21, 8:20 PM EDTTSTM WND DMGUniveter, GATREE AND POWERLINES DOWN... POSSIBLE ROOF DAMAGE TO NEARBY BUILDING
Mar 21, 8:23 PM EDTTSTM WND DMGCanton, GASEVERAL TREES DOWNED ALONG MAGNOLIA SPRINGS TRACE IN CANTON.
Mar 21, 8:24 PM EDTTSTM WND DMG1 Ese Belaire, GA2 TRACTOR TRAILERS WERE OVERTURNED ON I75 NEAR EXIT 288 DUE TO STRONG WINDS. CLOSEST NEARBY OBSERVING PLATFORM REPORTED 56 MPH GUST.
Mar 21, 8:25 PM EDTTSTM WND DMGWaleska, GAMULTIPLE REPORTS OF TREES AND POWER LINES DOWN IN THE WALESKA AREA...SEVERAL BRUSH FIRES CAUSED BY DOWNED POWER LINES
Mar 21, 8:30 PM EDTTSTM WND DMG1 Sw Avery, GATREES REPORTED DOWN AT THE INTERSECTION OF HICKORY FLAT HIGHWAY AND N STRINGER ROAD
Mar 21, 8:30 PM EDTTSTM WND DMG3 Ssw Matt, GATREES DOWN IN FORSYTH COUNTY...POSSIBLE TREE ON HOUSE ON PLEASANT GROVE ROAD.
Mar 21, 8:30 PM EDTTSTM WND DMGGlenell, GAMULTIPLE TREES DOWN ON POWERLINES AND A HOUSE
Mar 21, 8:30 PM EDTTSTM WND GST 612 S Cumming, GAGDOT RWIS SITE REPORTED 61 MPH WIND GUST WITH THE LINE
Mar 21, 8:35 PM EDTTSTM WND DMG3 Ese Kennesaw, GAPOWER LINES DOWN ON COBB PL BLVD NEAR BARRETT PKWY. ALL SOUTHBOUND LANES BLOCKED THRU WED MORNING.
Mar 21, 8:40 PM EDTTSTM WND DMGKingridge Estates, GAROAD SIGN REPORTED ON TOP OF A CAR AT INTERSECTION OF US-92 AND I-575.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Mar 21, 3:33 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.2 hours before the alert went out and 97 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 2017-03-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 377 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 2017-03-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 square meters per square second.193958Sfc1 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
377 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
2348 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
160 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

723 
WUUS52 KFFC 220014
SVRFFC
GAC015-057-067-085-115-117-121-223-233-220100-
/O.NEW.KFFC.SV.W.0079.170322T0014Z-170322T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Peachtree City GA
814 PM EDT TUE MAR 21 2017

The National Weather Service in Peachtree City has issued a

* Severe Thunderstorm Warning for...
  Northern Paulding County in northwestern Georgia...
  Cherokee County in north central Georgia...
  Western Forsyth County in north central Georgia...
  Northern Cobb County in north central Georgia...
  Southern Floyd County in northwestern Georgia...
  South central Dawson County in north central Georgia...
  Northeastern Fulton County in north central Georgia...
  Polk County in northwestern Georgia...
  Bartow County in northwestern Georgia...

* Until 900 PM EDT

* At 812 PM EDT, severe thunderstorms were located extending from
  near Hightower to near Canton to near Taylorsville to near Forney,
  moving southeast at 50 mph.

  HAZARD...60 mph wind gusts and nickel size hail. 

  SOURCE...Radar indicated, plus multiple reports of very strong 
           winds knocking down trees and powerlines across northwest 
           Georgia.

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Marietta, Rome, Canton, Cartersville, Dallas, Cedartown, Cumming,
  Sandy Springs, Roswell, Alpharetta, Milton, Kennesaw, Woodstock,
  Acworth, Holly Springs, Rockmart, Euharlee, Emerson, Ball Ground
  and Aragon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage across portions of north Georgia in the last hour. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows! 

If you see wind damage...hail or 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 or tweet us your report at NWSATLANTA.

&&

LAT...LON 3429 8538 3422 8524 3438 8456 3438 8444
      3435 8414 3417 8406 3394 8448 3391 8495
      3392 8539 3428 8546
TIME...MOT...LOC 0012Z 314DEG 42KT 3434 8418 3424 8455 3414 8503 3414
8546

HAIL...0.88IN
WIND...60MPH
 
$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 21, 8:00 PM EDTSpecial Weather StatementFFCWalton30 min
Mar 21, 8:02 PM EDTSevere Thunderstorm WarningFFCBanks, Jackson, Madison31 min
Mar 21, 8:07 PM EDTSevere Thunderstorm WarningFFCDawson, Fannin, Gilmer, Hall, Lumpkin, Pickens and 3 more38 min
Mar 21, 8:08 PM EDTSevere Thunderstorm WarningFFCMorgan, Oconee, Walton52 min
Mar 21, 8:19 PM EDTFlash Flood WarningFFCClarke, Greene, Oconee, Oglethorpe, Taliaferro, Wilkes6 hr
Mar 21, 8:30 PM EDTSpecial Weather StatementFFCOglethorpe45 min
Mar 21, 8:40 PM EDTSevere Thunderstorm WarningFFCCarroll, Clayton, Cobb, DeKalb, Douglas, Forsyth and 5 more50 min
Mar 21, 8:44 PM EDTSevere Thunderstorm WarningFFCBanks, Barrow, Forsyth, Gwinnett, Hall, Jackson and 2 more46 min
Mar 21, 8:49 PM EDTSevere Thunderstorm WarningFFCGreene, Oconee, Oglethorpe41 min
Mar 21, 9:20 PM EDTSpecial Weather StatementFFCButts, Clayton, Coweta, Fayette, Heard, Henry and 8 more40 min
Mar 21, 9:22 PM EDTSevere Thunderstorm WarningFFCBarrow, Clarke, Greene, Jackson, Madison, Morgan and 5 more38 min
Mar 21, 9:45 PM EDTSevere Thunderstorm WarningFFCGlascock, Greene, Hancock, Morgan, Oglethorpe, Putnam and 4 more45 min
Mar 21, 9:53 PM EDTSpecial Weather StatementFFCBaldwin, Butts, Harris, Jasper, Jones, Lamar and 7 more52 min
Mar 21, 10:24 PM EDTSpecial Weather StatementFFCBaldwin, Glascock, Hancock, Jefferson, Jones, Washington36 min
Mar 21, 10:55 PM EDTSpecial Weather StatementFFCEmanuel, Johnson, Wilkinson50 min
Mar 21, 11:51 PM EDTSpecial Weather StatementFFCMontgomery, Toombs39 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2017Every severe thunderstorm warning in 2017

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.