A line of rain showers was moving eastward along a frontal boundary during the afternoon. A brief spin up tornado occurred with one of these stronger rain showers within an area of weak rotation across eastern Roane County near the Oral community.
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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.
A line of rain showers was moving eastward along a frontal boundary during the afternoon. A brief spin up tornado occurred with one of these stronger rain showers within an area of weak rotation across eastern Roane County near the Oral community. Severe downdraft winds occurred sporadically in association with this briefly tornadic thunderstorm.
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 Aug 3, 1:12 PM EST, 8 minutes earlier.
Area Forecast Discussion National Weather Service Morristown TN 212 PM EDT Thu Aug 3 2023 ...New AVIATION... .UPDATE... Issued at 922 AM EDT Thu Aug 3 2023 Widespread showers continue this morning associated with isentropic ascent and a shortwave axis apparent on WV imagery moving across Kentucky. Recent surface analysis places an area of low pressure somewhere near STL or western Illinois with a surface boundary extended east across Kentucky and into portions of East Tennessee. Another convectively induced boundary is apparent from Arkansas, across southwest Tennessee, and northern Mississippi. The upper level disturbance is spreading large scale ascent across the region and will continue its eastward propagation late this morning and into the afternoon with a westerly low level jet continuing to focus low level moisture flux. Near term analysis places the best boundary layer convergence generally north of I-40 over the next 3-6 hours which is where FFG values are lowest. Luckily, instability remains weak with nearly moist adiabatic lapse rates limiting convective potential. However, deep warm cloud depths, and high PW values will continue to favor efficient warm rain process. Any training, and topographic effects could certainly add to the flash flood potential. Further south, the forecast is a bit more uncertain. Obviously this area has been much drier and the convective activity across west/middle Tennessee will likely stay mostly south of the forecast area. Still, some heavier rains will move into the southern southern zones through the morning and afternoon, but FFG is higher across these areas. As far as the current forecast, only small changes in PoPs were needed to match recent radar trends and near term guidance. Otherwise the forecast won't need any updates this morning. Updated && .SHORT TERM... (Today and tonight) Issued at 347 AM EDT Thu Aug 3 2023 Key Messages: 1. Isolated flash flooding threat possible today and tonight, mainly for central and northern areas where flash flood guidance is lower. 2. Possibility of some localized damaging winds exists in the far southern plateau and far southern TN valley later today. Better chances will be further south, in northern Alabama and northwest Georgia though. Discussion: Synoptically, the forecast area will remain situated beneath northwest flow aloft between an upper ridge over the southern plains and southern Miss river valley, and upper troughing over the Great Lakes and Ohio river valley areas. Multiple rounds of showers and embedded thunderstorms are expected to move through forecast area through the period, resulting in some chances for some localized flash flooding as well as a chance for some severe storms. In regards to the flooding chances... Isentropic analysis shows an area of focused ascent along the 305K surface across the northern half of the forecast area, and specifically northeast of the Morristown area. This lines up well with current radar imagery which shows the best coverage and intensity of ongoing showers in that same general area. The NAM seems to have this modeled well, and shows this ascent continue to strengthen through 12z this morning on the nose of the LLJ. Have already seen some 3-6hr radar estimates over 1.75" in the Claiborne/Hancock county line areas, and wouldn't be surprised to see some similar totals further east through daybreak. This area of ascent shifts east after daybreak, only to be replaced by chances for more widespread showers and embedded thunderstorms later in the morning as a decaying MCS moves into the southern valley and a convectively enhanced shortwave trough approaches from the northwest. Points in favor of some degree of flash flooding threat include forecast PWATs exceeding 2", very high freezing levels promoting efficient warm rain processes, and the possibility of convection training over the same areas from time to time. That being said, outside of the northeast parts of the forecast area (including the Claiborne/Hancock county area mentioned above), flash flood guidance on the 1hr, 3hr, and 6hr time scales are fairly high. Believe there is certainly a risk for some isolated flash flooding issues, but I'm not confident there's a widespread enough risk for any flood related headlines at this point. My gut instinct is to say the risk for any flooding issues is likely in the north, despite chances for stronger convection in the south later today. Storm motions will be faster there and combined with lower FFGs, may mitigate the flooding threat. Will opt to forego those at this time and just message flood risk through HWO and other avenues. Regarding the severe chances for today... Guidance supports a decaying MCS approaching the southern plateau around daybreak or so. This shouldn't pose any severe risk I don't believe, but a convectively enhanced shortwave will swing southeast across the CWA later today and should help spark off additional convection as it does so. SPC has just barely clipped our area (Marion county mostly) with a Slight risk area, and a 2 percent tornado contour as well. There is some support, both via deep layer shear and low level helicity, for a damaging wind threat and even risk of tornado via planar fields and BUFR soundings at Chattanooga. However, it must be said that the consensus is for a stronger signal south and west of our CWA. CAM guidance supports this as well. Overall, not very confident that there's any substantial severe threat in our forecast area but definitely worth monitoring as the day progresses. Otherwise, once the aforementioned shortwave moves through the area this evening, we should see rain chances shift south and east of the CWA along outflow induced boundaries and closer to better upper support. Don't have rain chances completely tailing off by the end of the period, but the trend in guidance is definitely towards drier conditions. Surface high pressure attempts to build back in tonight into early Friday morning. && .LONG TERM... (Friday through Wednesday) Issued at 347 AM EDT Thu Aug 3 2023 Key Messages: 1. Potential of lingering flooding concerns Friday has trended downwards along with expected coverage of showers/storms. 2. Daily chances of showers and storms exist through the extended, with Sunday and Monday currently looking like the best chances to see additional activity. Discussion: For Friday the synoptic pattern will gradually begin to shift to a more quasi-zonal flow setup with minor disturbances moving through mean flow aloft at times. These disturbances will combine with diurnal heating and result in daily chances of showers and thunderstorms, however, CAMs have trended with lower coverage of lingering storms, especially across northeastern portions of the area Friday. Cannot rule out isolated to weakly scattered activity but the best chance will exist in the southern valley/plateau in proximity to a stationary surface front west of the forecast area. A decrease in PWAT is noted in northeastern areas as well. As a result, the previous lingering flooding threat does not look to remain much of a concern at this time. Additional isolated showers and storms will favor the southern valley and higher elevations on Saturday. By late weekend, a more prominent shortwave trough will progress across the central CONUS and lead to more persistent swly H85 flow and subsequent isentropic lift. This will result in an uptick in chances for storms Sunday and into early next week as a frontal boundary approaches and passes through the region. Some discrepancies exist among long term guidance so the finer details remain a bit fuzzy. Ensemble guidance hints that troughing influence will bring reduced moisture availability after the passage of the front. NBM has populated with some slight to low end chance PoPs mid-week. This may be a little bullish given the dry airmass in GFS derived soundings but have left the wording as is for now. && .AVIATION... (18Z TAFS) Issued at 107 PM EDT Thu Aug 3 2023 Uncertain forecast through the next 24 hours. An upper level disturbance will bring shower activity to all sites this afternoon. Rain should begin to clear out this evening with low CIGS and visb impacting all sites. Prevailing MVFR is expected at all sites with IFR or lower at TRI. Guidance favors fog developing tonight at TRI with LIFR conditions. Additional showers and storms may develop back to the west, but its expected to remain to the west through the morning hours. May start to see some improvements in CIGS by the end of the period. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 73 88 70 91 / 50 50 20 30 Knoxville McGhee Tyson Airport, TN 70 84 67 89 / 40 30 10 10 Oak Ridge, TN 70 84 67 88 / 30 30 10 10 Tri Cities Airport, TN 67 82 64 87 / 50 40 10 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && SHORT TERM...CD LONG TERM....KRS AVIATION...Diegan
Hazardous Weather Outlook National Weather Service Morristown TN 427 AM EDT Thu Aug 3 2023 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-040830- 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- 427 AM EDT Thu Aug 3 2023 /327 AM CDT Thu Aug 3 2023/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...Today and Tonight Multiple rounds of showers and thunderstorms are expected today and tonight. Some isolated flooding will be possible, especially for areas that see repeated showers and thunderstorms. This could occur anywhere, but the better chances will likely be north of the I-40 corridor. Additionally, isolated damaging winds cannot be ruled out with any stronger storm this afternoon, mainly for portions of the southern Tennessee Valley and southern Cumberland Plateau. .DAYS TWO THROUGH SEVEN...Friday through Wednesday The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not needed at this time.
The Knoxville radar (KMRX), 94 km away, was scanning. The volume nearest the first event began at 18:19 UTC.
3 thunderstorm wind, 1 tornado, 1 flash flood. Local standard time, as filed.
Several trees and powerlines blown down by thunderstorm winds near Highway 70.
The tornado touched down in the community of Oral in eastern Roane County near the intersection of country lane and Highway 70. The tornado tracked eastward along Highway 70 for a half mile before dissipating near Oral Cemetery. The most significant damage occurred near the beginning of the track where a small detached garage was destroyed and debris strewn about 100 yards in different directions. A few trees were uprooted and homes and fences suffered minor damage. As the tornado continued east, damage was mainly limited to small branches broken from trees. Dissipation at Oral Cemetery was noted with a metal roof sheet laying in the cemetery and an end to minor vegetation damage.
Several trees were down along with roof damage to two homes caused by thunderstorm winds.
Severe thunderstorm winds on the right flank of the Oral tornado blew a small outbuilding onto its side, knocked down a couple of trees, and laid flat the grass all in one direction towards the path of the tornado.
Water covering Tusculum Blvd near Greeneville High School nearly a foot deep. Over six inches of water covering the road and entering structures and houses west of Tusculum. 911 Call center reported a few water rescues occurred on the east side of Greeneville between 4 pm and 5 pm EDT.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2023Every state in 2023This day in weather historyThe tornado archive for Tennessee, 2023Warnings in Tennessee, August 2023
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: 1112177, 1112176, 1112178, 1112179, 1133790.