An occluding surface low bringing a trailing cold front forced isolated severe thunderstorms in southwest Virginia, fueled by high effective shear and moderate amounts of instability.
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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 MRX wrote it up.
An occluding surface low bringing a trailing cold front forced isolated severe thunderstorms in southwest Virginia, fueled by high effective shear and moderate amounts of instability.
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, 2:41 PM EST, 1 hour 37 minutes earlier.
Area Forecast Discussion National Weather Service Morristown TN 341 PM EDT Tue May 20 2025 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Wednesday) Issued at 338 PM EDT Tue May 20 2025 Key Messages: 1. The threat for strong to severe storms with all hazards will continue through the early overnight hours. Continue to have multiple ways to receive watch and warning information. 2. Localized flash flooding threat may develop in flood prone location that see repeated strong to severe storms. 3. Severe threats will gradually diminish a few hours after midnight. Cooler and breezy conditions are expected Wednesday. As of 300PM ET a nearly stationary warm front remains draped across central and eastern KY as cold front approaches the Mid-Mississippi river valley. The parent low churns near the tri-state border of IA/MO/IL. On-going convection aided by an outflow boundary, 1000- 15000 J/kg MLCAPE, and 50kts EBShear, has warranted a tornado watch for Scott/Morgan counties northeast into southwest Virginia through 8PM ET in closer proximity of enhanced moisture convergence and low- level shear on southern side of the aforementioned warm front. The main focus point for this tornado threat will be embedded supercell structures within the line which will be capable of damaging straight line winds itself. Hail threat can of course accompany any rotating storm. Additional convection is expected to develop later this evening into the early overnight hours along and ahead of the cold front. This will bring another round of expected strong to severe storms. However, there will be some uncertainty on the northern side of I-40 and how well we destabilize after the on-going activity moves through the region. Some of the higher resolution guidance has started to hint at more pronounced bowing segments along and south of I-40 where the environment will be less tainted. Nonetheless, severe weather is likely with continued strong wind shear, marginal CAPE, and a strong strong swly LLJ near 40-45kts. Most likely timing will be between 8PM - 2AM ET. Some showers and storms will linger a bit longer but the widespread severe threat will diminish rather quickly around 3am or so. Breezy winds and cooler conditions will develop in a post frontal air mass Wednesday. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 338 PM EDT Tue May 20 2025 Key Messages: 1. Scattered showers and thunderstorms early in the period. 2. Cooler and mostly dry weather for Friday into Saturday. 3. Rain chances increase for Sunday through Tuesday. Discussion: We start the period with a broad upper trough over the eastern CONUS. While models are struggling with the details and timing, there is general agreement one or more short waves moving through the northwest flow aloft will bring scattered showers and possibly thunderstorms to our area in the Wednesday night/Thursday/Thursday night time frame. Freezing levels will be on the low side and model mid level lapse rates are steep, so if enough moisture and instability are present (which is still questionable), at least small hail will be possible with any thunderstorms. Surface high pressure will build in for Friday into Saturday, and both days look mostly dry and cool, with temperatures Friday looking to be around 10 degrees below normal and Saturday just a bit higher. The upper levels will be transitioning to more zonal flow for Sunday and Monday, and by Tuesday a strong short wave will be digging in to our west Tuesday. We will see moisture returning and more coverage of showers and thunderstorms for the Sunday through Tuesday period. High temperatures are forecast to be a little warmer, but still generally near to below normal all three days. && .AVIATION... (18Z TAFS) Issued at 142 PM EDT Tue May 20 2025 A line of showers and storms continue to move across central into eastern TN early this afternoon. This is expected to continue eastward into the late afternoon with best coverage along and north of I-40. Higher confidence in convective activity exists along cold front later this evening, generally near or just after midnight. High probabilities(60-80%) of brief MVFR or lower cigs developing behind the front tomorrow morning. Breezy west winds Wednesday afternoon gusting upwards of 20-25kts. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 67 81 60 80 / 80 0 10 20 Knoxville McGhee Tyson Airport, TN 66 78 58 75 / 90 10 10 40 Oak Ridge, TN 65 78 57 75 / 80 10 10 30 Tri Cities Airport, TN 62 76 53 71 / 90 20 10 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && SHORT TERM...KRS AVIATION...KRS
Hazardous Weather Outlook National Weather Service Morristown TN 343 PM EDT Tue May 20 2025 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-211945- 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-Northwest 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 VA-Russell-Washington VA- 343 PM EDT Tue May 20 2025 /243 PM CDT Tue May 20 2025/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...This Afternoon and Tonight Severe thunderstorms are expected to continue this afternoon and into the overnight hours ahead of a cold front. Damaging winds will be the primary risk, but there will be a chance of large hail and tornadoes with the strongest storms. .DAYS TWO THROUGH SEVEN...Wednesday through Monday The probability of widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not needed at this time.
Preliminary Local Storm Report
National Weather Service Morristown TN
336 PM EDT Tue May 20 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0310 PM Tstm Wnd Dmg 1 NNW Oliver Springs 36.05N 84.34W
05/20/2025 Roane TN 911 Call Center
Power lines down at lookout ave.
&&Preliminary Local Storm Report
National Weather Service Morristown TN
355 PM EDT Tue May 20 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 PM Tstm Wnd Gst Powell 36.03N 84.03W
05/20/2025 E60 MPH Knox TN NWS Employee
&&Special Weather Statement
National Weather Service Morristown TN
420 PM EDT Tue May 20 2025
TNZ016-038>040-042-070-202100-
Jefferson TN-Hamblen TN-Northwest Greene TN-Northwest Cocke TN-
Grainger TN-Hawkins TN-
420 PM EDT Tue May 20 2025
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN HAWKINS...
NORTHEASTERN JEFFERSON...NORTHERN COCKE...WESTERN GREENE...CENTRAL
GRAINGER AND HAMBLEN COUNTIES THROUGH 500 PM EDT...
At 420 PM EDT, Doppler radar was tracking a strong thunderstorm near
Jefferson City, moving east at 40 mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Caney Branch, Panther Creek State Park, Bulls Gap, Russellville,
McCloud, Romeo, Bybee, White Pine, Alpha, and Morristown.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until 800 PM EDT for east
Tennessee.
&&
LAT...LON 3603 8291 3603 8293 3601 8295 3609 8355
3624 8351 3639 8294
TIME...MOT...LOC 2020Z 262DEG 35KT 3614 8342
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPHSpecial Weather Statement
National Weather Service Morristown TN
454 PM EDT Tue May 20 2025
VAZ002-005-006-008-202145-
Washington VA-Scott VA-Wise VA-Russell VA-
454 PM EDT Tue May 20 2025
...STRONG THUNDERSTORMS WILL IMPACT SOUTHWESTERN RUSSELL...CENTRAL
SCOTT...WISE AND NORTHWESTERN WASHINGTON COUNTIES AND THE CITY OF
NORTON THROUGH 545 PM EDT...
At 454 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Norton to 6 miles north of Gate City.
Movement was northeast at 40 mph.
HAZARD...Wind gusts up to 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Coeburn, Dungannon, St. Paul, Norton, Wise, Big Stone Gap, Cleveland
Va, Lebanon, Collingwood, and Appalachia.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until 800 PM EDT for southwestern
Virginia.
&&
LAT...LON 3703 8248 3698 8237 3696 8236 3700 8229
3699 8226 3703 8220 3704 8215 3679 8199
3662 8271 3678 8280 3680 8277 3685 8284
3691 8288 3693 8286 3696 8287 3709 8252
TIME...MOT...LOC 2054Z 246DEG 35KT 3694 8272 3674 8260
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
SRSpecial Weather Statement
National Weather Service Morristown TN
456 PM EDT Tue May 20 2025
TNZ016-017-042-044-202145-
Sullivan TN-Washington TN-Northwest Greene TN-Hawkins TN-
456 PM EDT Tue May 20 2025
...A STRONG THUNDERSTORM WILL IMPACT WESTERN SULLIVAN...HAWKINS...
NORTHWESTERN WASHINGTON AND NORTHEASTERN GREENE COUNTIES THROUGH 545
PM EDT...
At 456 PM EDT, Doppler radar was tracking a strong thunderstorm near
Rogersville, moving east at 40 mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Gray, Mount Carmel, Oak Grove, McCloud, Spurgeon, Surgoinsville, Bays
Mountain Park, Sullivan Gardens, Fall Branch, and Warriors Path State
Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until 800 PM EDT for east
Tennessee...and southwestern Virginia.
&&
LAT...LON 3635 8242 3633 8308 3652 8310 3653 8309
3655 8295 3654 8295 3655 8294 3660 8255
3659 8245
TIME...MOT...LOC 2056Z 264DEG 37KT 3643 8296
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
SRPreliminary Local Storm Report
National Weather Service Morristown TN
501 PM EDT Tue May 20 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0427 PM Tstm Wnd Dmg 2 SSE Morristown 36.19N 83.29W
05/20/2025 Hamblen TN 911 Call Center
Numerous trees down HWY160 near Pinebrook.
&&The Jackson,KY radar (KJKL), 96 km away, was scanning. The volume nearest the first event began at 21:16 UTC.
3 thunderstorm wind. Local standard time, as filed.
Several trees were blown down by severe thunderstorm wind gusts.
Unknown sized hail fell during the storm in addition to the severe wind gusts felling several trees.
Several trees blown down by severe thunderstorm wind gusts.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2025Every state in 2025This day in weather historyWarnings in Virginia, May 2025
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: 1262925, 1262926, 1262927.