398
FXUS64 KMRX 070509
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
109 AM EDT Tue Oct 7 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1200 AM EDT Tue Oct 7 2025

- A cold front Tuesday into Wednesday will bring chances of rain
  and storms back to the region.

- Temperatures will continue to be unseasonably warm; 5 to 10
  degrees above normal through Tuesday. More seasonal readings and
  a return to drier conditions are anticipated by the second half
  of the week.

&&

.DISCUSSION...
Issued at 129 PM EDT Mon Oct 6 2025

Currently, an upper ridge is in place over the eastern CONUS with
a trough axis stretching through the Northern Plains into the
Intermountain West. A weak area of surface low pressure sits atop
the ArkLaMiss region. Relatively higher cloud coverage and light
radar returns have been noted along the Cumberland Plateau and
Southern Valley as isentropic lift taps into enhanced moisture
advection.

Overall, pretty minimal impacts over the next 12-18 hours - just
light precip chances focused over the Cumberland Plateau. As we
approach mid-day and into Tuesday afternoon the aforementioned
troughing will quickly glide across central and into eastern
portions of the CONUS. An approaching cold front will lead to
increasing chances of showers and a few thunderstorms. Coverage
will be greatest Tuesday night when vort maxima and frontal
forcing best align. This is expected to be largely beneficial
rainfall for the area despite anomalous PWAT values between
1.6-1.8 inches. This is due to lackluster thermodynamic profiles
with NAMBufr soundings showing MUCAPE less than 1000 J/kg. NBM
probability of precip greater than 0.25" has increased to 60% or
greater across our whole CWA. Prob of precip greater than 1" does
reach the 50-60% range along the N Plateau, N valley, into SW
Virginia.

Precipitation associated with the front is expected to clear out
of the area through late Wednesday morning, with a mostly dry
afternoon. A shift to northerly winds will induce a return to more
seasonal temperatures Wednesday as well. NBM paints dry conditions
through the remainder of the forecast period onwards. Reinforcing
shortwaves will enhance troughing over the southern Appalachians,
eventually becoming a closed low by the weekend. This will allow
near normal temperatures to persist.

&&

.AVIATION...
(06Z TAFS)
Issued at 1200 AM EDT Tue Oct 7 2025

Will see some showers, especially late in the period, and a few
rumbles of thunder will be possible mainly CHA and perhaps TYS as
well late in the period. Will see VFR conditions much of the
period, but MVFR conditions likely to occur with showers at CHA,
and then a trend toward more prevailing MVFR late in the period
at CHA and TYS as showers increase frequency.


&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             81  68  80  59 /  40  80  20  10
Knoxville McGhee Tyson Airport, TN  81  67  75  55 /  30  90  20  10
Oak Ridge, TN                       79  65  75  53 /  60  90  20  10
Tri Cities Airport, TN              80  64  71  49 /  30  90  40   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$

DISCUSSION...99
AVIATION...99