Showers and thunderstorms moved out of Middle Tennessee into a moist and unstable atmosphere across East Tennessee. The result was multiple severe thunderstorms that produced damaging wind gusts.
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.
Showers and thunderstorms moved out of Middle Tennessee into a moist and unstable atmosphere across East Tennessee. The result was multiple severe thunderstorms that produced damaging wind gusts.
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 31, 1:51 PM EST, 1 hour 54 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Morristown TN 251 PM EDT Fri Jul 31 2020 .SHORT TERM... (Today through Tomorrow)... A line of showers and thunderstorms across Middle Tennessee will continue move eastward south of the front through the rest of the afternoon and evening. Satellite imagery shows that the eastern Tennessee Valley has cleared today allowing temperatures to warm and the atmosphere to destabilize after the round of morning storms. Mesoanalysis indicates upwards of 2500 J/kg of MLCAPE over east Tennessee this afternoon. DCAPE values this afternoon are around 800 J/kg, but very little shear this far north. In addition the PWAT values will remain very high, close to 2 inches, meaning there will be abundant moisture for storms to tap into. So the main threats with storms this afternoon remains strong straight-line winds and heavy downpours leading to flooding. High resolution CAMs are indicating this initial wave moves through this afternoon helping to stabilize and clear out most of the area, but another round moving out of middle Tennessee up towards the Cumberland Plateau closer to midnight as the surface low and front move nearer to the region. With all the rain we've already received and more expected this evening, we may see fog develop overnight and into the morning hours, especially along the Cumberland Plateau over towards SW Virginia where rain will occur later in the evening/night. Tomorrow, the front will be approaching the region, and another round of showers and thunderstorms can be expected ahead of it. Better jet dynamics closer to the low/trough means that storms will be capable of becoming more organized in the afternoon/evening, but shear still looks somewhat weak at this point based on forecast soundings. A lot of it will depend on how much we clear out tonight/tomorrow ahead of any storm formation. But once again, the biggest threat with storms tomorrow will be damaging straight-line winds and heavy downpours leading to flooding. ABM .LONG TERM...(Saturday night through Friday)... Overall, not much change compared to the last long term issuance. We begin the period with an unseasonably deep trough across the area. This trough lingers through Tuesday night/Wednesday and will allow for increased chances for showers and storms. Saturday night, a surface low is lifting off to the northeast into the Ohio River Valley. A few lingering storms can be expected from the afternoon hours but coverage should be on the decrease. The cold front associated with the low passes through Saturday night but will get hung up across the Appalachians on Sunday. This will provide focus for showers and storms through the day but with the highest POPs along the foothills of the Appalachians and Appalachians themselves. Chance POPs in place elsewhere. On Monday, another area of low pressure moves down into the existing trough and into the Ohio River Valley. The associated cold front will begin to move across west TN through the day. At the same time, what is currently Hurricane Isaias, will be approaching the coastal Carolinas and spreading moisture northwest into the Appalachian region. The approaching cold front and increasing moisture from Isaias will provide another day of chance and likely POPs. Tuesday we step back down to Chance POPs across all areas as drier air moves in behind the front. Temperatures during this period will be in the low to mid 80s, which is near normal to a few degrees below normal. Wednesday through Friday the flow begins to become more zonal as the trough lifts off to the north. During the time, we can expect a return to normal summer-time conditions where the highest POPs will be along the high terrain with lower chances down in the valley. This activity will be diurnally driven, which is what we expect for this time of year. Temperatures during the last few days of the period will be warming back into the mid and upper 80s, closer to normal. SR && .AVIATION... 18Z TAF DISCUSSION. Line of storms currently across Middle Tennessee is expected to move eastward through the afternoon. Conditions should likely remain VFR but if/when a storm hits it will quickly degrade with strong storms. Should recover relatively quickly after storms move through. Depending on where rain occurs this afternoon/evening we could see fog develop tomorrow morning, but left it out of the TAFs due to uncertainty at this time. Another round of storms is expected tomorrow. ABM && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 73 90 70 88 68 / 50 50 30 30 30 Knoxville McGhee Tyson Airport, TN 72 91 71 87 68 / 60 50 40 40 30 Oak Ridge, TN 71 89 69 87 67 / 60 50 40 30 30 Tri Cities Airport, TN 69 90 69 86 66 / 60 50 40 60 50 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
Hazardous Weather Outlook National Weather Service Morristown TN 241 PM EDT Fri Jul 31 2020 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-011845- 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- 241 PM EDT Fri Jul 31 2020 /141 PM CDT Fri Jul 31 2020/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...This Afternoon and Tonight A round of storms is expected this afternoon through this evening. A moist and unstable airmass will produce scattered strong to possible severe thunderstorms. Main concern will be torrential rains and potentially more flash flooding. Isolated damaging winds are also possible. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Strong to severe storms will be possible late Saturday afternoon into the evening. Best chances for severe weather will generally be along and west of Interstate 75. The main threat from these storms will be isolated damaging wind gusts. Heavy rainfall with these storms could also lead to the possibility of localized flash flooding. A strong to marginally severe storm cannot be ruled out again on Sunday afternoon across northeast Tennessee and southwest Virginia with an isolated damaging wind gust being the main threat. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed this afternoon and again on Saturday.
Special Weather Statement
National Weather Service Morristown TN
420 PM EDT Fri Jul 31 2020
TNZ067-083-084-312045-
Rhea TN-Roane TN-Meigs TN-
420 PM EDT Fri Jul 31 2020
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN RHEA...NORTHEASTERN
MEIGS AND SOUTHWESTERN ROANE COUNTIES UNTIL 445 PM EDT...
At 419 PM EDT, Doppler radar was tracking a strong thunderstorm near
Spring City, or 13 miles southwest of Rockwood, moving northeast at
15 mph.
Pea size hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Rockwood, Spring City, Grandview, Piney Falls State Park and Eagle
Furnace.
LAT...LON 3575 8493 3578 8490 3578 8488 3583 8480
3582 8478 3586 8473 3590 8471 3590 8468
3570 8454 3565 8486
TIME...MOT...LOC 2019Z 240DEG 12KT 3574 8485
CEDThe Knoxville radar (KMRX), 127 km away, was scanning. The volume nearest the first event began at 20:44 UTC.
19 thunderstorm wind. Local standard time, as filed.
Numerous trees down in Rockwood and Philadelphia as well as south of River Road.
Snapped trees and downed power lines were reported in Huntsville.
Many trees reported down across the county along with widespread power outages.
Several trees reported down in Dutch Valley.
Several trees reported down in the Briceville area.
Strong winds contributed to a partial barn collapse in Halls.
Numerous trees reported down on Tell Mynatt Road in Halls.
Multiple trees reported down across the county.
Multiple trees reported down across the county.
Reports of a lot of trees and power lines down in Tazewell. A tree fell on a home near Cane Circle and one home had some siding blown off.
Numerous trees reported down across the county.
Many trees and power lines were reported down across the county.
Trees and power lines were reported down across the county.
Several trees were reported down across the Morristown area.
Several trees were down in the Newman Ridge area north of Sneedville.
Many trees reported down across the county.
Numerous trees down across the county.
Many trees were reported down across the county.
Several trees were reported down from Milligan College to Hampton and southeast to Roan Mountain. One tree fell on a home in Hampton.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2020Every state in 2020This day in weather historyWarnings in Tennessee, 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: 900061, 900062, 900063, 900064, 900065, 900066, 900067, 900068, 900158, 900069, 900070, 900071, 900072, 900073, 900074, 900075, 900076, 900077, 900078.