Knoxville, Tennessee 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

099
FXUS64 KMRX 192322
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
722 PM EDT Thu Mar 19 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 706 PM EDT Thu Mar 19 2026

- Spring-like temperatures this weekend. Highs Sunday will be 15
  to 20 degrees above normal.

- Widely scattered to scattered storms Saturday afternoon. Low-end
  potential of small hail with these thunderstorms. Confidence is
  too low to include within the HWO.

- Cooler airmass for early next week but still near to slightly
  above normal.

&&

.DISCUSSION...
Issued at 224 PM EDT Thu Mar 19 2026

Strong upper ridge across the Great Basin and troughing in the
east with northwest flow aloft will be the predominant weather
pattern throughout the forecast.

For Tonight through Friday night, dry northwest flow aloft with
surface ridging slowly eroding and moving east. Warming trend will
continue with low afternoon relative humidity in the 30s most
locations Friday.

For Saturday, deterministic and ensemble models show a wave
dropping southeast into the central and southern Appalachians.
Increase in southwest boundary layer flow will pull moisture back
into the region. Ensemble CAPE/Shear combo show enough instability
for scattered afternoon convection. Depending on the low-level
moisture return and mid-level lapse rates (around 6.5-6.7 degrees)
some of the storms could produce small hail. Low confidence on
this threat so did not include within the HWO.

For Sunday, this wave has moved east of the region with building
heights producing an unseasonably warm day. Highs will be 15 to 20
degrees above normal. Here are the records for Sunday:

Date  Chattanooga  Knoxville  Tri-Cities  Oak Ridge
3-22  89(1907)     87(1907)   81(1938)    83(2011)

A stronger upper short-wave will move across Great Lakes into the
northeast/Mid-atlantic states for Sunday night and early Monday.
This wave will pull a frontal boundary southeast into the region.
A chance of showers will accompany the front especially across
southwest Virginia and northeast Tennessee. Ensemble QPF is pretty
light and less than one-tenth inch.

Dry northwest flow for Monday night and Tuesday with more seasonal
temperatures. Another fast moving wave in the northwest flow aloft
is possible by mid-week next week.

&&

.AVIATION...
(00Z TAFS)
Issued at 706 PM EDT Thu Mar 19 2026

VFR TAFs expected through the period. Light winds until southwest
flow begins increasing tomorrow morning, with 15 to 20 knots in
the afternoon area wide, with 25 knots possible at KTYS. Generally
high cirrus clouds in the sky tomorrow.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             43  77  53  83 /   0   0  10  10
Knoxville McGhee Tyson Airport, TN  41  72  54  79 /   0   0  10  20
Oak Ridge, TN                       40  72  52  79 /   0   0  10  20
Tri Cities Airport, TN              34  67  51  72 /   0  10  20  20

&&

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

$$

DISCUSSION...DH
AVIATION...Wellington