A weak frontal boundary, low level instability and abundant low level moisture produced scattered severe thunderstorms across the area.
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 weak frontal boundary, low level instability and abundant low level moisture produced scattered severe thunderstorms across the area.
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 Jul 24, 2:17 PM EST, 2 hours 43 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Morristown TN 317 PM EDT Fri Jul 24 2020 .SHORT TERM (Tonight and Saturday)... Convection will decrease in coverage after loss of daytime heating and the associated stabilizing of the atmosphere. Expect clearing conditions overnight with fog near areas that received rainfall. Upper ridging remains anchored across the middle of the nation with a 594-595dam upper 500mb ridge centered across Kansas and Missouri producing weak northerly flow across the region. Low level SE flow between a ridge across the Mid- Atlantic and Tropical Storm Hanna near south Texas. This will continue to produce an area of weak 850mb-700mb convergence across southern and central portions of the forecast area. Synoptic forcing is very weak on Saturday allowing mesoscale factors to be the primary contributors to convective development and organization. With daytime heating, instability will be on the increase with NAM soundings showing MLCAPE between 1500 to 2500 J/Kg by early afternoon. With differential heating along the higher terrain, thunderstorm initiation is expected by midday. Pulse convection will be the primary mode with deep layer shear less than 10 kt. In addition, DCAPE values will be higher on Saturday which may enhance the risk of isolated microbursts with descending thunderstorm cores. HREF guidance shows low-level moisture will remain high with PW values across the southern half of the forecast area between 1.8 to 2.0 inches contributing to locally heavy rainfall and isolated flooding. Convective coverage will follow a diurnal curve with a decrease in activity during the late evening and early overnight hours. JB .LONG TERM (Saturday night through Friday night)... Through the weekend, an elongated ridge of high pressure aloft will stretch from the southern plains east through the mid Atlantic. A northern stream shortwave will move through southern Canada and the northern plains. Typical summertime weather will result with afternoon scattered showers and thunderstorms expected. Temperatures near to slightly above normal can be expected Saturday night and Sunday. On Monday, the northern stream shortwave drops out of southern Canada and into the Great Lakes with an attendant cold front moving through the Ohio valley. Lower heights and southerly low level flow will enhance precipitation chances Monday and Monday night before the cold front approaches on Tuesday. Increased cloud cover and precipitation should keep temperatures slightly cooler on Monday. Frontal passage occurs on Tuesday and Tuesday night. Upper disturbance ejects northeast allowing the cold front to weaken as it moves through the region. Coverage of showers and thunderstorms should pick up on Tuesday with this period likely having the highest PoPs. Start to see model diverge regarding the strength of the ridge across the southeast. The ECMWF seems to break the ridge down more with a more amplified pattern while the GFS keeps the ridge, although still weak. However, guidance does agree that northwest flow will setup across the Tennessee valley toward the end of the period with continued chances of showers and thunderstorms and near normal temperatures. Diegan && .AVIATION... 18Z TAF DISCUSSION. Scattered showers and thunderstorms are expected this afternoon with the highest coverage forecast to be near TYS and CHA. This will result in tempo MVFR, and potential brief IFR, conditions. Convection will decrease after sunset with drier conditions overnight. With some clearing, expect patchy fog to develop. Highest confidence in MVFR or lower vis is at TRI where guidance is in good agreement with MVFR or IFR fog development late tonight and early Saturday morning. JB && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 73 92 72 91 73 / 30 40 20 50 20 Knoxville McGhee Tyson Airport, TN 71 90 71 91 72 / 20 30 20 50 20 Oak Ridge, TN 71 90 70 91 71 / 20 40 20 50 20 Tri Cities Airport, TN 67 89 67 89 68 / 30 30 20 50 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
Hazardous Weather Outlook National Weather Service Morristown TN 319 PM EDT Fri Jul 24 2020 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-251930- Cherokee-Clay-Scott-Campbell-Claiborne-Hancock-Hawkins-Sullivan- Johnson-Morgan-Anderson-Union-Grainger-Hamblen-Northwest Cocke- Cocke Smoky Mountains-Northwest Greene-Southeast Greene- Washington-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-Russell- 319 PM EDT Fri Jul 24 2020 /219 PM CDT Fri Jul 24 2020/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...This Afternoon and Tonight Scattered showers and thunderstorms are expected this afternoon and early evening with a few strong to marginally severe storms possible. Isolated damaging wind gusts and brief heavy rainfall are the main concerns. .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter reports of severe weather or flooding are encouraged. Please relay any information about severe weather to the NWS while following local, state, and CDC guidelines.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
520 PM EDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0430 PM TSTM WND DMG 2 S PAULETTE 36.16N 83.90W
07/24/2020 KNOX TN LAW ENFORCEMENT
SEVERAL TREES DOWN.
&&
DHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
529 PM EDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0529 PM TSTM WND DMG 4 SSE HOWARD QUARTER 36.42N 83.40W
07/24/2020 CLAIBORNE TN PUBLIC
A FEW TREES DOWN.
&&
DHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
540 PM EDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0530 PM TSTM WND DMG 2 ENE SNEEDVILLE 36.55N 83.17W
07/24/2020 HANCOCK TN LAW ENFORCEMENT
SEVERAL TREES DOWN.
&&
DHPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MORRISTOWN TN
549 PM EDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0449 PM TSTM WND DMG MAYNARDVILLE 36.24N 83.80W
07/24/2020 UNION TN LAW ENFORCEMENT
SEVERAL TREES DOWN ACROSS THE AREA.
0503 PM TSTM WND DMG 2 E TURTLETOWN 35.12N 84.32W
07/24/2020 POLK TN PUBLIC
SEVERAL TREES DOWN AND HAIL UP TO PENNY
SIZE.
0513 PM TSTM WND DMG 2 NNE MALONEYVILLE 36.11N 83.82W
07/24/2020 KNOX TN LAW ENFORCEMENT
SEVERAL TREES AND POWER LINES DOWN.
0430 PM TSTM WND DMG 2 S PAULETTE 36.16N 83.90W
07/24/2020 KNOX TN LAW ENFORCEMENT
SEVERAL TREES DOWN.
0530 PM TSTM WND DMG 2 ENE SNEEDVILLE 36.55N 83.17W
07/24/2020 HANCOCK TN LAW ENFORCEMENT
SEVERAL TREES DOWN.
0505 PM TSTM WND DMG 1 N SNEEDVILLE 36.56N 83.21W
07/24/2020 HANCOCK TN LAW ENFORCEMENT
SEVERAL TREES DOWN ACROSS THE AREA.
0529 PM TSTM WND DMG 4 SSE HOWARD QUARTER 36.42N 83.40W
07/24/2020 CLAIBORNE TN PUBLIC
A FEW TREES DOWN.
0437 PM TSTM WND DMG 7 NW HOWARD QUARTER 36.55N 83.49W
07/24/2020 CLAIBORNE TN PUBLIC
SEVERAL TREES DOWN WITH HIGH WINDS.
0419 PM TSTM WND DMG 2 E DUFF 36.45N 84.03W
07/24/2020 CAMPBELL TN PUBLIC
SEVERAL TREES DOWN.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
554 PM EDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0554 PM TSTM WND DMG 1 W RUSSELLVILLE 36.26N 83.21W
07/24/2020 HAMBLEN TN PUBLIC
SEVERAL TREES DOWN ACROSS THE AREA.
&&
DHSpecial Weather Statement National Weather Service Morristown TN 559 PM EDT Fri Jul 24 2020 TNZ086-242245- Northwest Monroe TN- 559 PM EDT Fri Jul 24 2020 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL MONROE COUNTY UNTIL 645 PM EDT... At 559 PM EDT, Doppler radar was tracking a strong thunderstorm over Madisonville, moving southeast at 5 mph. Winds in excess of 45 mph will be possible with this storm. Locations impacted include... Madisonville, Vonore, Tellico Plains, Tariffville and Mount Vernon. 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. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 3552 8444 3560 8429 3547 8413 3535 8433 TIME...MOT...LOC 2159Z 324DEG 5KT 3552 8433 DH
The Knoxville radar (KMRX), 106 km away, was scanning. The volume nearest the first event began at 21:59 UTC.
2 thunderstorm wind. Local standard time, as filed.
Several trees reported down just northeast of Fort Blackmore.
A few trees were reported down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2020Every state in 2020This day in weather historyWarnings in Virginia, July 2020
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: 900052, 900053.