A mesoscale convective system moved from north to south across the Cumberland Plateau while a second convective system moved from west to east across the most southern Tennessee counties.
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 mesoscale convective system moved from north to south across the Cumberland Plateau while a second convective system moved from west to east across the most southern Tennessee counties.
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 Jun 25, 12:27 PM EST, 10 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Morristown TN 127 PM EDT Sun Jun 25 2023 ...New AVIATION... .UPDATE... Issued at 950 AM EDT Sun Jun 25 2023 Approaching convection in central KY and Middle TN is the main concern for the afternoon. Visible satellite has been showing elevated convection across Middle TN all morning, with little to no convection in our area, suggesting a more stable environment in East TN and eastern KY. As the MCS tracks east, the southern end of the line extending into Middle TN will likely be the main area of intensification and deep convective development, while the northern portions of the line will likely weaken as they encounter a more stable environmnent. The 13Z HRRR seems to be underdone on the developing storms in northern Middle TN. So for our area, the area of the highest severe threat is expected to be in the Cumberland Plateau around noon, and central and southern sections from noon to 3 pm. Damaging winds will be the main threat, with a lower potential for hail around 1". The main change for the update will be to adjust PoPs upward for western and southern sections early this afternoon, with a quicker drop in PoPs in the mid to late afternoon. A second round of storms with greater severe potential is expected tonight. No change in the forecast reasoning has changed with that round; see below for that discussion. && .SHORT TERM... (Today and tonight) Issued at 413 AM EDT Sun Jun 25 2023 Key Messages: 1. It still looks like the MCS over Illinois early this morning will reach the forecast area around noon to 2 pm EDT and with its south to southeast movement affect southern sections through mid to late afternoon. Potential for a few strong to marginal severe storms. 2. Then this evening another area of storms moving south from the Ohio Valley will affect the region mainly after midnight until about 12Z Monday. Discussion: Early this morning skies were mostly clear with patchy fog, locally dense across parts of the region. A mid to upper level trough lies across the northeast part of the eastern Tennessee Valley but ridging aloft was covering the southwest part. The forecast area is expected to be impacted later today by an upstream MCS that is over Illinois this morning. the trajectory of this system later this morning into the afternoon is to the south southeast and should affect the northern plateau by early this afternoon and progress southward to cover most of the western half of the area. Showers and some thunderstorms area expected. The NAM model and CAMS are showing the stronger storms across middle Tennessee and parts of the plateau. Scattered less intense storms will be possible across the remainder of the area. Stabilization in the wake of the initial convection results in more uncertain convective potential across parts of the Tennessee into lower Ohio Valleys later this afternoon. A narrow corridor of moderate to strong pre-frontal destabilization across Indiana into southern Michigan may provide another focus for strong thunderstorm initiation this afternoon. This activity across Indiana (the NAM model shows this) drops south through KY after 00Z tonight and then through the forecast area between about midnight and 12Z Monday. The best instability and forcing will be to the north and northwest of the forecast area in the afternoon and evening but there will still be a threat for damaging winds and marginally large hail tonight as the thunderstorms move into the plateau counties and parts of the Tennessee Valley. There will also be a risk for a few tornadoes. Temperatures today will be just below normal with the early sun in the lower to mid 80s and upper 80s in Chattanooga. Tonight with clouds initially decreasing and then increasing later temperatures will only drop into the mid 60s to near 70 at Chattanooga. && .LONG TERM... (Monday through Saturday) Issued at 413 AM EDT Sun Jun 25 2023 Key Messages: 1. Possibility of a few strong storms with gusty winds late Monday. 2. Warming trend through the end of the week. 3. Mostly dry Tuesday onward, but persistent northwest flow aloft will likely yield some scattered showers and thunderstorms at times. Discussion: Generally speaking, the period will feature a vertically stacked upper low over the Great Lakes to start, with a cold front moving through Mon afternoon and evening. This feature eventually opens up and becomes a synoptic scale trough over the eastern CONUS by late Tue, with a strengthening ridge over the plains and Mississippi river valley. The trough holds on over the mid-Atlantic and New England areas through late week, despite the strengthening ridge, which will keep northwesterly flow aloft locally. This will allow for diurnal rain chances to continue most days, with the possibility of seeing some sort of MCS activity at some point as well. One thing to note however is that with the ridge strengthening to our west and a retreating trough to our northeast, models do show some fairly warm H85 temperatures advecting this direction by week's end, which should push highs up into the 90s. Going into a little more detail about Monday, the period will likely begin with remnant MCS activity either moving southeastward across, or exiting the CWA altogether. Some guidance has us completely dry after daybreak Monday, before more convection fires along a cold front that will move through during the afternoon. It seems reasonable that there will be a lull in rain chances, but given at least some uncertainty in timing and path of the Sun night/Mon morning MCS, prefer not to to take PoPs down to zero completely just yet. As mentioned, a trailing cold front should move through late Monday afternoon. This should result in another round of convection during that time. Confidence on the severe threat with that round of storms is low as it depends on the placement of the incoming front as well as low level moisture and resulting instability. Given the likelihood of an MCS sweeping through Mon morning, it seems reasonable to lean towards a more GFS like solution which features lower dewpoints and a much more deeply mixed atmosphere Mon afternoon and evening. The HREF ensemble mean surface based CAPE values support this, showing more instability over the mountains and points eastward late Mon. Even still, forecast soundings show steep mid level lapse rates Mon afternoon and evening which will coincide with a vort lobe moving around the southern periphery of the aforementioned Great Lakes upper low. Even with the lesser instability of the GFS/HREF, the mid level lapse rates and thermal profiles would support thunder and even an outside chance of some gusty winds given the possibility of noteworthy DCAPE values due to more deeply mixed low levels. Better severe chances will exist east of the TN/NC line, which is where the Day 2 SPC outlook categories are higher. && .AVIATION... (18Z TAFS) Issued at 124 PM EDT Sun Jun 25 2023 Storms are about to move into TYS, with gusts to around 30 kt and IFR vis/heavy rain expected. This complex of storms will spread south down the TN Valley, and affect CHA around 20-23Z. A second round of storms is expected later tonight, mainly between 06-10Z at the TAF sites. These storms may also produce gusty winds and IFR conditions briefly, and possibly hail. Prevailing VFR conditions should return ater 12Z tomorrow as clouds clear out of the area. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 70 89 67 89 / 60 20 10 0 Knoxville McGhee Tyson Airport, TN 69 87 65 85 / 80 20 10 10 Oak Ridge, TN 67 87 64 85 / 80 10 0 10 Tri Cities Airport, TN 66 85 62 81 / 60 20 20 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
Hazardous Weather Outlook National Weather Service Morristown TN 439 AM EDT Sun Jun 25 2023 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-260845- 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- 439 AM EDT Sun Jun 25 2023 /339 AM CDT Sun Jun 25 2023/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...Today and Tonight Thunderstorms are possible at times Sunday afternoon through early Monday morning, with the greatest probability Sunday night. Some of the storms Sunday night may become strong to severe. The primary threats will be damaging wind and large hail, however, a brief spin-up tornado cannot be totally ruled out along the northern Cumberland Plateau. .DAYS TWO THROUGH SEVEN...Monday through Saturday A cold front will move through Monday afternoon and evening. A few strong storms may accompany this front, especially in the northeast part of the forecast area. These storms could produce some marginally severe winds. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed tonight. TD/CD
Special Weather Statement
National Weather Service Morristown TN
103 PM EDT Sun Jun 25 2023
TNZ035-067-068-251745-
Roane TN-Loudon TN-Morgan TN-
103 PM EDT Sun Jun 25 2023
...A strong thunderstorm will impact portions of southeastern Morgan,
central Loudon and Roane Counties through 145 PM EDT...
At 103 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles north of Rockwood, moving southeast at 30 mph.
HAZARD...Winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Oak Ridge, Lenoir City, Kingston, Rockwood, Loudon, Wartburg,
Fairview, Midtown, Harriman and Oakdale.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3565 8461 3568 8463 3571 8462 3573 8464
3572 8466 3585 8475 3587 8472 3589 8471
3591 8468 3599 8472 3604 8476 3617 8447
3594 8429 3590 8427 3584 8421
TIME...MOT...LOC 1703Z 324DEG 28KT 3598 8470
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
KRSThe Knoxville radar (KMRX), 96 km away, was scanning. The volume nearest the first event began at 17:37 UTC.
13 thunderstorm wind, 2 hail. Local standard time, as filed.
Several trees were reported blown down by thunderstorm winds across the county.
Several trees were blown down at this location by strong thunderstorm wind gusts.
Numerous trees blown down by severe thunderstorm winds across the county.
Numerous trees were reported to be blown down across the southern end of Blount County.
Several trees were knocked down by strong thunderstorm winds.
Several trees were blown down by thunderstorm wind gusts.
A few trees were blown down by thunderstorm winds.
Several trees were blown down by severe wind gusts.
A few trees were reported blown down by severe thunderstorm winds.
Several trees were blown down by severe thunderstorm winds across the county.
Several trees were blown down by severe thunderstorm winds.
A few trees were blown down by severe thunderstorm winds.
Several reports of trees blown down by strong thunderstorm winds across the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2023Every state in 2023This day in weather historyWarnings in Tennessee, June 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: 1105254, 1105255, 1105258, 1105260, 1105261, 1105262, 1105259, 1105263, 1105264, 1105265, 1105266, 1105278, 1105252, 1105279, 1105253.