The back door front had mostly washed out, but southwesterly flow aloft on the west side of the Bermuda High kept the area quite humid. A cold front was approaching from the Mississippi and Ohio Valleys, and heavy convective rain was training along southwest-to-northeast oriented bands, producing significant flash flooding.
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.
The back door front had mostly washed out, but southwesterly flow aloft on the west side of the Bermuda High kept the area quite humid. A cold front was approaching from the Mississippi and Ohio Valleys, and heavy convective rain was training along southwest-to-northeast oriented bands, producing significant flash flooding.
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 Sep 26, 3:15 AM EST, 10 minutes earlier.
Area Forecast Discussion
National Weather Service Morristown TN
415 AM EDT Wed Sep 26 2018
.SHORT TERM...(Today and Tonight)...
Excessive rain and flooding will be our primary weather hazards
for today. A strong upper trough and 120 kt jet across the Great
Lakes will strengthen a surface low as it moves northeastward into
Canada. A surface cold front will move south toward the Tennessee
Valley and Southern Appalachians with a surge of moisture ahead
of the front. Forecast soundings show a saturated vertical
profile, a warm cloud layer depth of 10-12k ft, and PW of 1.9 to
2.1 inches (near the max of climatology). This will favor heavy
rain capable of producing localized flooding. CAM guidance
continues to point toward 2” to 4” totals across southeast
Tennessee with localized higher totals not out of the question.
FFG in this region is already low with 6-hr FFG of less than 3.0
inches, and across parts of Hamilton, Meigs, and Rhea Counties is
less than 2.0 inches. For this reason, will have a Flash Flood
Watch across portions of southeast Tennessee where FFG is lower
and flooding risk is maximized. With widespread rain and clouds,
temperatures will be near normal in the upper 70s.
This front stalls across the Southern Appalachians tonight with
additional periods of heavy rain possible across far southeast
Tennessee and southwest North Carolina with unsettled weather into
Thursday.
.LONG TERM...(Thursday through Tuesday)...
The extended range forecast periods initializes on Thursday
morning amidst broad and nearly full latitude longwave troughing
across the central CONUS, while at the surface weak high pressure
looks to move into the TN valley region from the west behind a
cold front. With that, guidance remains a bit uncertain regarding
the fropa as most sources favor the boundary stalling near/atop
the southern Appalachians on Thursday. Eventually the southern
stream shortwave embedded in the mean longwave flow will lift
northeast across the region Thursday evening, which should work to
drive the front eastward into Friday. Unfortunately antecedent
conditions will be quite degraded across portions of the fcst area
(mainly along/south of I40 as well as the southern mountains),
given expected rainfall today/tonight. The stalled frontal axis,
its associated moisture, and these precursor conditions will at
least extend the heavy rainfall and flash flooding threat
into/through Thursday. Thus a flash flood watch will be issued
through 00z Friday for these areas.
Moving on, by Saturday the old front looks to have pushed southward
while another relatively dry reinforcing cold front approaches from
the northwest. The jury is still out with regards to how far south
this next front makes it, yet it does look like zonal flow aloft and
some drier llv advection will yield lower pops than days past. High
pressure north of this frontal boundary will slide by to the north
atop the OH valley, eventually moving quickly off the New England
coastline to start the new work week. With that, sly llv flow will
return to the TN valley region yielding waa beneath a large upper
ridge centered over the southeast. All said, pops will return to
more of a diurnal trend to round out the period given no major
synoptic features to affect the area through Wednesday morning.
Temperatures through the extended range will slowly moderate from
below normal levels Thursday/Friday given ample sky cover and
precipitation, to above normal levels amidst a drier airmass and
building heights aloft.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 77 67 76 67 / 90 60 60 60
Knoxville McGhee Tyson Airport, TN 77 66 75 66 / 90 60 80 60
Oak Ridge, TN 76 65 74 65 / 90 50 60 50
Tri Cities Airport, TN 77 64 73 63 / 80 70 80 60
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...Flash Flood Watch through Thursday evening for Bledsoe-Blount
Smoky Mountains-Bradley-East Polk-Hamilton-Loudon-Marion-
McMinn-Meigs-NW Blount-Northwest Monroe-Rhea-Roane-
Sequatchie-Southeast Monroe-West Polk.
VA...None.
&&
JB/CDGThe Northeast Alabama radar (KHTX), 92 km away, was scanning. The volume nearest the first event began at 08:27 UTC.
7 flash flood, 1 flood. Local standard time, as filed.
Flash flooding near Hixson Pike and Hamby Road. Nearby rain gauge reported 3.28 inches of rain in 6 hours.
Numerous roads closed across the county.
Mobile home flooded and a vehicle stranded in flood waters along Igou Ferry Road.
Hickman Lane closed by flooded creek.
A 61 year old woman was swept away by flood waters while attempting to retrieve her dog. Extensive flood damages in the community around Soddy-Daisy occurred throughout the event, and the damage estimate obtained from the Emergency Manager is included in this entry.
Numerous roads remained closed throughout the county.
Several roads closed by flooding around the Kingston area. Water up to a foot deep in places.
Roadways flooded with 6 inches of water around Walker Springs and Gallaher View Roads. Standing water on Cedar Bluff Road.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flash Flood, Hamilton | 2018-09-26 | 61 | Female | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2018Every state in 2018This day in weather historyWarnings in Tennessee, September 2018
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: 787247, 787248, 787249, 787267, 787252, 787257, 787259, 787266.