Alert archive / Georgia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 80, NWS Atlanta, GA

March 21, 201711 counties in Georgia

NWS Atlanta, GA issued this severe thunderstorm warning at Mar 21, 2017, 8:40 PM EDT for 11 counties in Georgia. It was in force for 50 min. 13 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, 8:40 PM EDT (00:40 UTC)
Expired
Mar 21, 2017, 9:30 PM EDT
In force
50 min
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Carroll County, GA, Clayton County, GA, Cobb County, GA, DeKalb County, GA, Douglas County, GA, Forsyth County, GA, Fulton County, GA, Gwinnett County, GA, Haralson County, GA, Paulding County, GA, Polk County, GA

The radar

The Atlanta radar (KFFC), 65 km from the middle of the area, began a volume at 00:41 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, 8:40 PM EDTTSTM WND DMG1 Nnw Greyfield, GAON GROVE PARKWAY SE... A LARGE TREE GREATER THAN 4 FEET IN DIAMETER WAS UPROOTED AND FELL INTO THE STREET.
Mar 21, 8:55 PM EDTTSTM WND DMG1 Nnw Johns Creek, GATREES REPORTED DOWN NEAR THE INTERSECTION OF FINDLEY CHASE DRIVE AND FINDLEY ROAD
Mar 21, 8:55 PM EDTTSTM WND DMG1 S Chattawood, GATREE ON PARK BLUFF LANE
Mar 21, 8:57 PM EDTTSTM WND DMG1 Nne Johns Creek, GATREES REPORTED DOWN AT THE INTERSECTION OF JOHNS CREEK PARKWAY AND MEDLOCK BRIDGE ROAD
Mar 21, 8:57 PM EDTTSTM WND DMG1 Nw Bethesda, GATREE ON A HOUSE ON FERRITE LOOP IN LAWRENCEVILLE
Mar 21, 8:58 PM EDTTSTM WND DMGRiver Colony, GATREE ON A HOME ALONG RALEIGH WAY IN LAWRENCEVILLE AREA
Mar 21, 8:58 PM EDTTSTM WND GST 831 E Stone Mountain, GAMEASURED WIND GUST OF 83 MPH FROM WEATHER STATION ATOP STONE MOUNTAIN.
Mar 21, 8:59 PM EDTTSTM WND DMG1 E The Wildings, GATREE ON HOUSE ON CARLYSLE INN CT
Mar 21, 8:59 PM EDTTSTM WND DMG1 W Pine Lake, GASEVERAL TREES REPORTED DOWN ON CARS AND HOUSES ALONG VERONA DRIVE. TIME ESTIMATED FROM RADAR.
Mar 21, 9:00 PM EDTTSTM WND DMGOak Grove, GALARGE TREE FELL ON HOME ON CORALWOOD DR
Mar 21, 9:05 PM EDTTSTM WND DMG1 Ese North Dekalb, GALARGE TREE FELL ON HOME ON TANNER DR
Mar 21, 9:05 PM EDTTSTM WND DMG1 Ese North Dekalb, GAPUBLIC AND MEDIA REPORTING MULTIPLE LARGE OAK TREES BLOWN OVER... 2 OF WHICH FELL ON HOMES NEAR TANNER DR
Mar 21, 9:09 PM EDTTSTM WND DMG2 Ene Habersham Hills, GANUMEROUS REPORTS OF TREES DOWN THROUGHOUT GWINNETT COUNTY ACROSS ROADS.. NOTABLY I85 AT MM 117 IN BUFORD.

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, 0.7 hours before the alert went out and 64 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.

075 
WUUS52 KFFC 220040
SVRFFC
GAC045-063-067-089-097-117-121-135-143-223-233-220130-
/O.NEW.KFFC.SV.W.0080.170322T0040Z-170322T0130Z/

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

The National Weather Service in Peachtree City has issued a

* Severe Thunderstorm Warning for...
  Paulding County in northwestern Georgia...
  DeKalb County in north central Georgia...
  Southwestern Forsyth County in north central Georgia...
  Central Carroll County in northwestern Georgia...
  Cobb County in north central Georgia...
  Haralson County in northwestern Georgia...
  Douglas County in north central Georgia...
  Gwinnett County in north central Georgia...
  Fulton County in north central Georgia...
  Northwestern Clayton County in north central Georgia...
  Southern Polk County in northwestern Georgia...

* Until 930 PM EDT

* At 838 PM EDT, severe thunderstorms were located extending from
  near Milton to Sandy Plains to near Eubank Lake to near Piedmont,
  moving southeast at 40 mph.

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

  SOURCE...Radar indicated, plus multiple reports of downed trees 
           and powerlines due to the very strong winds.

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

* Locations impacted include...
  Atlanta, Marietta, Douglasville, Lawrenceville, Carrollton,
  Decatur, Dallas, Cumming, Buchanan, Sandy Springs, Roswell, Johns
  Creek, Alpharetta, Smyrna, Dunwoody, East Point, Milton, Kennesaw,
  Duluth and Acworth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms have been producing 
widespread wind damage across northwest and north central Georgia. 
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 3398 8508 3408 8450 3407 8442 3411 8442
      3412 8437 3415 8436 3423 8418 3393 8380
      3388 8386 3364 8428 3356 8485 3354 8531
      3396 8540
TIME...MOT...LOC 0038Z 334DEG 33KT 3414 8423 3401 8449 3392 8505 3390
8558

HAIL...0.75IN
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, 8:14 PM EDTSevere Thunderstorm WarningFFCBartow, Cherokee, Cobb, Dawson, Floyd, Forsyth and 3 more46 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, 8:44 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.