Ravens Lore Trail, Tennessee Weather Forecast Discussion

162
FXUS64 KMRX 181136
AFDMRX
Area Forecast Discussion
National Weather Service Morristown TN
736 AM EDT Thu Sep 18 2025
...New AVIATION...
.DISCUSSION...
Issued at 134 AM EDT Thu Sep 18 2025
Key Messages:
1. Unseasonably warm temperatures will persist into next week.
However, no threat of any daily max T records being broken.
2. Mostly dry conditions expected through the weekend. Limited
chances of an isolated shower or storm are primarily confined to
higher elevations of the E TN mountains Friday and Saturday.
3. Chances for rain return area-wide Tuesday into the middle of
next week.
Discussion:
Typical patchy fog pattern around area waterways, otherwise, quiet
weather conditions and mild temperatures through the overnight.
Shortwave ridging will continue to shift eastward this afternoon. H5
height rises of 1-3dam will translate to temperatures roughly 3-5
degrees warmer per mid September standards. A notable capping
inversion near 750mb on NAMBufr soundings will suppress convection
keeping the area dry.
Minor height rises will continue to promote above normal
temperatures Friday and Saturday. Though, as the aforementioned
inversion weakens, isolated diurnal convection across the East
Tennessee mountains will be possible in a typical summertime
pattern. The NAM does depict a weak impulse and greater presence of
vort lobes swinging through the southern Appalachian Saturday. This
could lead to isolated activity making its way into valley locations
as well, but mostly dry overall.
The shortwave ridge begins to lift north and east as an upr trough
dips into southern Canada and north-central CONUS Sunday into
Monday. Upper flow becomes more quasi-zonal locally. Temperatures
may decrees a degree or two relative to previous days, but will
ultimately maintain the pattern of slightly above normal. NBM
continues to promote a dry forecast for this time frame but it is
possible some slight chance/isolated PoPs get introduced across
higher terrain as high-res guidance enters temporal scale.
Shortwave energy will promote deepening of a closed, potentially
cutoff, low developing over the CONUS Tuesday onwards. Precipitation
chances (15-35%) make a return Tuesday through the end of the
forecast period as a result. While it does not look to be a
washout per say, the persistent probabilities of precipitation
fall on inconsistencies between deterministic guidance on all
position, timing, and amplitude of the synoptic feature.
&&
.AVIATION...
(12Z TAFS)
Issued at 655 AM EDT Thu Sep 18 2025
Will start with brief MVFR cigs at TRI, but otherwise we will see
VFR conditions for most of the the remainder of the period all
sites. The only other exception will be late in the period, when
fog will be possible. The highest chance for this fog looks to be
at TRI, so will have a couple of hours of MVFR vsby in the
forecast there toward sunrise.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             89  63  90  64 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  86  61  88  63 /   0   0   0   0
Oak Ridge, TN                       86  61  88  62 /   0   0   0   0
Tri Cities Airport, TN              83  57  85  58 /   0   0   0   0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DISCUSSION...KRS
AVIATION...

NWS MRX Office Area Forecast Discussion