Knoxville, Tennessee 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

099
FXUS64 KMRX 232311 AAA
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
611 PM EST Tue Dec 23 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 609 PM EST Tue Dec 23 2025

- Low rain chances tonight mainly north of I-40. Otherwise cloudy
skies and maybe some drizzle today and tomorrow.

- Unseasonable warm weather through the weekend, especially Thursday
through Saturday.

- Rain showers are expected off and on from Wednesday night through
Friday night mainly north of I-40. Rain amounts will be light.

- The best chance for widespread rain will be Sunday with a cold
front moving through the region in the evening.

- Much colder airmass moves into the Tennessee valley and southern
  Appalachians for late Sunday and especially early next week.

&&

.DISCUSSION...
Issued at 1226 PM EST Tue Dec 23 2025

In the upper levels, a strong ridge is over the Central U.S. At the
surface, high pressure is over the Southeast and a low is moving
through Eastern Canada today bringing a weak boundary near or just
north of the region. Very low rain chances are present today and
tomorrow with some drizzle possible at times. Tonight rain chances
are better with some light showers possible off and on as the
boundary dips southward. CAMs show scattered light showers tonight.
Rain amounts will be low with weak forcing and limited moisture
present. Another chance for light rain is possible late Wednesday
night through Thursday night mainly north of I-40 as a series minor
waves move through the pattern with a strong ridge over the Central
U.S. There may also be remnants of the stalling surface boundary
still present over the region. Again, any rain amounts will be light
with limited moisture present.

The ridge flattens by Friday bringing nearly zonal flow aloft. A
weak surface low will move through the Ohio Valley Friday bringing
low light rain chances off and on Thursday night through Friday
night. The best chance for rain will be Sunday when a more
substantial system will bring widespread rain chances to the region.
A clean cold front passage is expected around Sunday evening with
much colder temps arriving Sunday night or Monday.

A warming trend continues with the warmest days expected to be
Thursday through Saturday. Temperatures will be above normal all
week through the weekend. Chattanooga will have a shot at the record
high on Christmas Day with the forecast at one degree below.

Christmas Day:

                 Forecast High     Normal High      Record High
Chattanooga:           74               52               75
Knoxville Airport:     69               49               76
Tri-Cities:            64               48               74

&&

.AVIATION...
(00Z TAFS)
Issued at 609 PM EST Tue Dec 23 2025

The general trend to cigs through the night is expected to be
lowering to MVFR around midnight, with periods of IFR at TRI
toward sunrise. IFR may be possible at TYS as well, but confidence
is low. Gradual lifting and/or scattering of cigs may come in the
afternoon at all sites, but confidence is the timing of this is
low.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             56  72  56  74 /  10  10  10  10
Knoxville McGhee Tyson Airport, TN  56  67  57  69 /  40  20  20  30
Oak Ridge, TN                       54  66  56  69 /  40  20  30  20
Tri Cities Airport, TN              50  62  51  64 /  50  10  50  70

&&

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

$$

DISCUSSION...McD
AVIATION...DGS