A lone thunderstorm formed during the afternoon across Southeast Tennessee which produced a severe wind gust which downed a few trees.
Every event with a place to put it. Tap one for its entry below.
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 MRX wrote it up.
A lone thunderstorm formed during the afternoon across Southeast Tennessee which produced a severe wind gust which downed a few trees.
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 Morristown, TN wrote its last area forecast discussion before the first event at May 20, 2:00 PM EST, 1 hour 51 minutes earlier.
Area Forecast Discussion National Weather Service Morristown TN 300 PM EDT Sun May 20 2018 .SHORT TERM...(Tonight and Monday)...Upper heights continue to rise across the southern Appalachians this afternoon atop weak high pressure at the surface allowing for ample heating. With that, convective initiation has occurred across the higher terrain of both the mtns/Plateau. Further heating this afternoon is expected to favor additional coverage in the southern TN valley as convective temps are reached/exceeded. Guidance still seems to suggest that any weak capping will hold for valley locations north of I40. Thus, the fcst features high end chance to low likely pops close to the GA/AL/TN lines, tapering to slight chances along I40, then down to non mentionable levels closer to KY. As for threats today, any convection that does occur could reach to heights supportive of small hail. Likewise, given relatively weak motion vectors, think storms could also present a concern for brief heavy rainfall and isolated flash flooding, although not likely. Otherwise, coverage will diminish with heating loss tonight leading into a partly cloudy evening. Ample moisture in the decoupled BL could lead to another night of patchy fog, the most dense of which is favored in the valleys of extreme northeast TN and southwest VA, as well an any locales receiving good rainfall today. Much the same on Monday as mainly diurnal heating induced convection is favored while a weak upper disturbance amidst the broader H5 flow rotates atop the FL gulf coast. With that, pops will be a bit higher as deeper moisture advects northward, therefore the fcst will feature regionwide likely pops on Monday. Temperatures on Monday with remain slightly above normal levels .LONG TERM...(Monday night through Sunday)...The Northeastern U.S. upper trough amplifies early in the period helping to push a frontal boundary south through the forecast area. There will be a higher chance of showers and thunderstorms across the forecast area on Tuesday ahead of the front. However, probability will be dropping across much of the area through the end of the work week as drier and slightly more stable air filters into the region. Moisture and instability will be gradually increasing over the weekend ahead of another Midwest upper trough. A few more showers and thunderstorms will be possible across the area in this environment, so raised pops into a higher chance category over the weekend. High temperatures will be generally in the lower and middle 80s through Wednesday, and then may inch up a bit into the middle and upper 80s in the slightly drier airmass behind the boundary. Lows will be mainly in the lower and middle 60s, although may be a little warmer as moisture returns later in the week. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 69 82 66 82 / 40 60 30 50 Knoxville McGhee Tyson Airport, TN 68 82 64 82 / 20 60 30 50 Oak Ridge, TN 67 84 65 83 / 20 60 30 50 Tri Cities Airport, TN 63 82 61 80 / 10 60 30 50 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && CDG/TH
Hazardous Weather Outlook National Weather Service Morristown TN 304 PM EDT Sun May 20 2018 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-211915- Cherokee-Clay-Scott TN-Campbell-Claiborne-Hancock-Hawkins- Sullivan-Johnson-Morgan-Anderson-Union-Grainger-Hamblen- Northwest Cocke-Cocke Smoky Mountains-Northwest Greene- Southeast Greene-Washington TN-Unicoi-Northwest Carter- Southeast Carter-Roane-Loudon-Knox-Jefferson-NW Blount- Blount Smoky Mountains-North Sevier-Sevier Smoky Mountains- Sequatchie-Bledsoe-Rhea-Meigs-McMinn-Northwest Monroe- Southeast Monroe-Marion-Hamilton-Bradley-West Polk-East Polk-Lee- Wise-Scott-Russell-Washington- 304 PM EDT Sun May 20 2018 /204 PM CDT Sun May 20 2018/ This Hazardous Weather Outlook is for portions of Southwest North Carolina...East Tennessee and Southwest Virginia. .DAY ONE...This Afternoon and Tonight Isolated to scattered showers and thunderstorms are expected through the afternoon hours. Some of these storms could become strong with small hail, gusty winds, cloud to ground lightning, and brief heavy rainfall being the primary threats. .DAYS TWO THROUGH SEVEN...Monday through Saturday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. CDG
Special Weather Statement
National Weather Service Morristown TN
252 PM EDT SUN MAY 20 2018
TNZ067-201930-
Roane TN-
252 PM EDT SUN MAY 20 2018
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN ROANE COUNTY UNTIL
330 PM EDT...
At 251 PM EDT, Doppler radar was tracking a strong thunderstorm near
Rockwood. This storm was nearly stationary.
Half inch hail and winds in excess of 30 mph will be possible with
this storm.
Locations impacted include...
Kingston, Rockwood, Fairview, Midtown, Harriman and Eagle Furnace.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3572 8468 3572 8470 3574 8470 3576 8476
3579 8474 3582 8479 3586 8473 3589 8471
3593 8465 3585 8449 3572 8463 3573 8464
3570 8467
TIME...MOT...LOC 1851Z 311DEG 4KT 3585 8475
CDGSpecial Weather Statement
National Weather Service Morristown TN
323 PM EDT SUN MAY 20 2018
TNZ082-083-099-202015-
Rhea TN-Bledsoe TN-Hamilton TN-
323 PM EDT SUN MAY 20 2018
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN RHEA...SOUTH
CENTRAL BLEDSOE AND NORTHEASTERN HAMILTON COUNTIES UNTIL 415 PM
EDT/315 PM CDT/...
At 323 PM EDT/223 PM CDT/, Doppler radar was tracking a strong
thunderstorm near Dayton, moving southeast at 5 mph.
Dime size hail and winds in excess of 30 mph will be possible with
this storm.
Locations impacted include...
Dayton, Graysville, Brayton and Sale Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3548 8521 3555 8509 3544 8493 3545 8496
3540 8502 3538 8503 3532 8514
TIME...MOT...LOC 1923Z 323DEG 8KT 3547 8511
CDGSpecial Weather Statement National Weather Service Morristown TN 337 PM EDT SUN MAY 20 2018 TNZ081-098-099-202015- Sequatchie TN-Marion TN-Hamilton TN- 337 PM EDT SUN MAY 20 2018 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN SEQUATCHIE...EASTERN MARION AND WEST CENTRAL HAMILTON COUNTIES UNTIL 415 PM EDT/315 PM CDT/... At 337 PM EDT/237 PM CDT/, Doppler radar was tracking a strong thunderstorm near Whitwell, or 8 miles southwest of Dunlap, moving southeast at 5 mph. Half inch hail and winds in excess of 30 mph will be possible with this storm. Locations impacted include... Chattanooga, Dunlap, Soddy-Daisy, Signal Mountain, Walden, Whitwell, Fairmount, Powells Crossroads, Martin Springs, Cartwright, North Chickamauga Creek Gorge, Griffith Creek, Chimneys State Park, Hicks Gap State Park, Lone Oak, Falling Water, Middle Valley and Mowbray Mountain. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3528 8563 3539 8545 3522 8518 3502 8546 TIME...MOT...LOC 1937Z 323DEG 7KT 3528 8550 CDG
Special Weather Statement National Weather Service Morristown TN 410 PM EDT SUN MAY 20 2018 TNZ081-098-099-202045- Sequatchie TN-Marion TN-Hamilton TN- 410 PM EDT SUN MAY 20 2018 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN SEQUATCHIE...EASTERN MARION AND SOUTHWESTERN HAMILTON COUNTIES UNTIL 445 PM EDT/345 PM CDT/... At 410 PM EDT/310 PM CDT/, Doppler radar was tracking a strong thunderstorm near Fairmount, or 11 miles northwest of Chattanooga. This storm was nearly stationary. Dime size hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Chattanooga, Soddy-Daisy, Signal Mountain, Walden, Whitwell, Fairmount, Red Bank, Powells Crossroads, Cartwright, Hicks Gap State Park, Lone Oak, Falling Water, Middle Valley, Chimneys State Park and North Chickamauga Creek Gorge. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3524 8556 3532 8543 3517 8516 3501 8547 TIME...MOT...LOC 2010Z 319DEG 1KT 3520 8539 JLB
Special Weather Statement National Weather Service Morristown TN 412 PM EDT SUN MAY 20 2018 TNZ083>085-099-100-202045- Rhea TN-Bradley TN-Hamilton TN-Meigs TN-McMinn TN- 412 PM EDT SUN MAY 20 2018 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL RHEA...NORTH CENTRAL BRADLEY...SOUTHWESTERN MEIGS...SOUTHWESTERN MCMINN AND NORTHEASTERN HAMILTON COUNTIES UNTIL 445 PM EDT... At 412 PM EDT, Doppler radar was tracking a strong thunderstorm 8 miles southeast of Dayton, moving south at 10 mph. Nickel size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Charleston, Birchwood, Hillsview, Big Spring and Sale Creek. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3544 8506 3548 8484 3529 8476 3526 8509 TIME...MOT...LOC 2012Z 345DEG 10KT 3540 8493 JLB
Special Weather Statement National Weather Service Morristown TN 425 PM EDT SUN MAY 20 2018 TNZ067-068-085-086-202100- Northwest Monroe TN-Roane TN-Loudon TN-McMinn TN- 425 PM EDT SUN MAY 20 2018 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL LOUDON...NORTH CENTRAL MCMINN...NORTHWESTERN MONROE AND CENTRAL ROANE COUNTIES UNTIL 500 PM EDT... At 424 PM EDT, Doppler radar was tracking a strong thunderstorm near Kingston, moving south at 15 mph. Dime size hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Oak Ridge, Lenoir City, Kingston, Loudon, Midtown, Harriman, Philadelphia, Paint Rock, Bradbury and Tellico Village. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3590 8455 3593 8433 3564 8425 3562 8458 TIME...MOT...LOC 2024Z 353DEG 14KT 3584 8444 JLB
The Northeast Alabama radar (KHTX), 101 km away, was scanning. The volume nearest the first event began at 20:52 UTC.
1 thunderstorm wind. Local standard time, as filed.
Several trees were reported down along highway 64 near the Hamilton County line.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2018Every state in 2018This day in weather historyWarnings in Tennessee, May 2018
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: 745944.