A weakening mid-level wave approaching north Georgia from the Tennessee Valley brought isolated severe thunderstorms to far north Georgia late in the evening.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FFC wrote it up.
A weakening mid-level wave approaching north Georgia from the Tennessee Valley brought isolated severe thunderstorms to far north Georgia late in the evening.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Atlanta, GA wrote its last area forecast discussion before the first event at May 27, 9:15 PM EST, 1 hour 1 minute earlier.
Area Forecast Discussion National Weather Service Peachtree City GA 1015 PM EDT Sat May 27 2017 .UPDATE... ...Severe Thunderstorm Watch In Effect For Portions of North GA... Always a tough call with these NW flow events and in this case...WNW flow event. First wave moved through this morning as just clouds mainly which really stabilized things longer than the models had projected. Making up for lost time now though with CAPE values pushing 2500 J/KG. There has also been an extensive cap to overcome as evidenced by impressive warming on 00Z FFC sounding. Hard to discern how far this extends into North GA and honestly not likely to matter for the first tier of counties given momentum of initial MCS. But certainly could see some weakening prior to entering the southern half of the watch but enough uncertainty there that thought it best in coordination with SPC to go another tier of counties. After that...depends more on further upstream convection and if it makes a late night run at us which would have a better chance of impacting the metro. For now have kept Atlanta area in the chance pops except northern burbs where likely will be in place. Will be a fluid situation with updates to pop grids likely to continue into the overnight period. Deese && .PREV DISCUSSION... /issued 757 PM EDT Sat May 27 2017/ PREV DISCUSSION... /issued 247 PM EDT Sat May 27 2017/ SHORT TERM /Today through Monday/... A rather complicated forecast as a series of disturbances moves across the CWA beginning tonight and through Sunday night. The MCS that was over TN early this morning has dissipated and has not put out an outflow. The hi-res models eventually caught on to this, but they still struggle with developing convection and moving it into GA. The HRRR has flip-flop several times this morning and the WRF/ARW continue to develop convection over TN and move it southeast. The problem with this is that showers that have developed over TN are moving northeast. The other issue is the strong cap over the CWA between 800 and 700 mb. Unless there is forcing, areas in north Georgia would need to rise to near 100 degrees before breaking the cap. Latest models suggest the cap doesn't break down until Sunday morning. Have opted to go with GFS/NAM deep moisture and associated short waves to forecast the best areas for thunderstorms, which at this time both the GFS/NAM agree on extreme north Georgia tonight and Sunday with the better chances in north Georgia Sunday night. As for severe potential, if any storms develop, there is still the risk of isolated severe storms as CAPES continue to run high as well as 0 - 6km bulk shear. 17 LONG TERM /Monday Night through Friday/... A largely unsettled period can be expected through the long-term. Monday continues to exhibit the best chance for strong to severe thunderstorm activity as a front enters the area with abundant instability in place by Monday afternoon. The remainder of the extended will continue to see chances for convection each day with plentiful moisture and southwest flow aloft. Refer to the previous long-term discussion below for additional details. RW PREVIOUS LONG TERM /Issued 356 AM Sat May 27 2017/ Main forecast concern in long term period is chance for strong/severe convection on Monday. 00Z model guidance in pretty good agreement with Monday forecast. Front progged to continue to sag into the state Monday with above normal sfc temps and dewpoints. SBCAPE rises to fairly high values even for late May, GFS 2500-3500 J/kg. Deep layer shear should be sufficient for severe convection, 0-6km bulk shear mags > 30kts over much of the CWA, however low level shear quite weak with 0-1km bulk shear around 5-10kts. In such environments, we typically see severe storms with large hail and wind threats but very low risk of tornadoes. PW will be fairly high but not too abnormally high for this time of year (GFS values around 1.6 in). With large scale lift not too high, QPF also less than 1 inch in most locations Mon, so will likely see periods of heavy rain but flash flooding risk somewhat low. After front sags into middle or south GA, essentially washes out Tuesday. Moisture remains plentiful but without any forcing, any storms would be fairly isolated thru Thursday. Have kept PoPs fairly low but unlikely we will see a dry period with weak SWly flow aloft. By Thurs Night or Friday, warm advection should kick in with increase in moisture as well. Have bumped up PoPs then. SNELSON AVIATION... 00Z UPDATE... VFR conditions to start out in the short term although do expect to continue with periods of mid level cigs for the next several hours. Biggest issue will be trying to time potential TSRA episodes with guidance all over the place with possibilities. For now...into the overnight looks like the best chances but confidence so low that will only include VCSH for now. Intrusion of lower clouds from the SW overnight will require MVFR cigs aft 10Z for all sites. //ATL CONFIDENCE...00Z UPDATE... Medium on TSRA chances. High on remaining elements. Deese && .PRELIMINARY POINT TEMPS/POPS... Athens 70 89 70 87 / 30 40 30 50 Atlanta 71 87 69 84 / 30 20 20 60 Blairsville 62 84 63 79 / 70 50 60 60 Cartersville 70 86 69 83 / 60 40 50 60 Columbus 71 90 73 87 / 10 10 10 60 Gainesville 69 86 68 83 / 60 50 50 50 Macon 69 93 72 89 / 10 10 10 40 Rome 69 86 69 83 / 60 50 70 60 Peachtree City 69 88 71 85 / 20 20 20 60 Vidalia 70 93 72 92 / 5 10 10 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...Deese LONG TERM....20 AVIATION...Deese
Hazardous Weather Outlook...Updated National Weather Service Peachtree City GA 915 PM EDT Sat May 27 2017 GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086- 089>098-102>113-281815- Baldwin-Banks-Barrow-Bartow-Bibb-Bleckley-Butts-Carroll-Catoosa- Chattahoochee-Chattooga-Cherokee-Clarke-Clayton-Cobb-Coweta- Crawford-Crisp-Dade-Dawson-DeKalb-Dodge-Dooly-Douglas-Emanuel- Fannin-Fayette-Floyd-Forsyth-Gilmer-Glascock-Gordon-Greene- Gwinnett-Hall-Hancock-Haralson-Harris-Heard-Henry-Houston-Jackson- Jasper-Jefferson-Johnson-Jones-Lamar-Laurens-Lumpkin-Macon- Madison-Marion-Meriwether-Monroe-Montgomery-Morgan-Murray- Muscogee-Newton-North Fulton-Oconee-Oglethorpe-Paulding-Peach- Pickens-Pike-Polk-Pulaski-Putnam-Rockdale-Schley-South Fulton- Spalding-Stewart-Sumter-Talbot-Taliaferro-Taylor-Telfair-Toombs- Towns-Treutlen-Troup-Twiggs-Union-Upson-Walker-Walton-Warren- Washington-Webster-Wheeler-White-Whitfield-Wilcox-Wilkes- Wilkinson- 915 PM EDT Sat May 27 2017 This Hazardous Weather Outlook is for portions of North and Central Georgia. .DAY ONE...Tonight... The chance for thunderstorms will increase across far north Georgia this evening into the overnight hours. A few of these storms could become strong or severe with large hail, damaging winds, frequent lightning, and even an isolated tornado. .DAYS TWO THROUGH SEVEN...Sunday through Friday... Thunderstorms will be possible Sunday and especially Monday as a weak cold front moves through the state. The best chance for severe storms will be on Monday with large hail, damaging winds heavy rainfall and frequent lightning likely. As the front washes out, moisture will linger and daytime heating will cause isolated thunderstorms, some possibly strong, on Tuesday through Friday with greater chances on Thursday and Friday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested but spotters are encouraged to submit reports of severe weather through the web by going to weather.gov/atlanta.
The Northeast Alabama radar (KHTX), 83 km away, was scanning. The volume nearest the first event began at 03:15 UTC.
2 thunderstorm wind. Local standard time, as filed.
The Catoosa County 911 center reported a tree blown down near the intersection of Three Notch Road and Buster Ridge Lane.
The Murray County 911 center reported a tree blown down on Mantooth Road south of Halls Chapel Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Georgia in 2017Every state in 2017This day in weather historyWarnings in Georgia, May 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 704277, 704282.