581
FXUS64 KMRX 221144
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
744 AM EDT Mon Jun 22 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 735 AM EDT Mon Jun 22 2026

- Scattered showers and storms are likely on Monday, with the
  potential for strong/severe storms in the afternoon/evening.

- Dry weather Tuesday and Wednesday, then, daily rain chances
  return late in the week, with temperatures near normal.

&&

.DISCUSSION...
Issued at 257 AM EDT Mon Jun 22 2026

An area of strong storms may weaken but move into the Plateau and
southwest VA very early this morning before sunrise. Confidence
is low but possible.

For Monday, a series of abnormally strong jets for mid-June will
effect the area. The more northerly stream jet over the Ohio valley
will start to produce increasing upper divergence over Tennessee
valley in the afternoon with convection developing across the
Plateau counties. This feature combined with another short-wave and
jet over the mid and lower Mississippi River valley will combine
to produce large scale forcing over the region from mid-afternoon
into the evening hours.

The forcing combined with moderate instability with MLCAPES of 1500-
200 will produce at least scattered to broken areas of showers and
thunderstorms. Due to DCAPES of 800-900 and PWs increasing to over 2
inches, strong downbursts winds are possible. Mid-level lapse rates
are quite limited and less than 6 degrees so hail is not expected.
Some of the CAMS suggest the potential of some backing of boundary
layer winds across southeast Tennessee. This backing would increase
the potential of brief spin-ups but this is a very low-end
threat.

Another concern for late Monday afternoon and evening is the
potential of flash flooding. Latest CAMS and deterministic models
show PWs increasing to well over 2 inches which will be near the
climo max for mid-June. Also, the increasing 850mb jet will produce
strong moisture transport into the region. Storm motion will be in
the 25+ knots but if an outflow boundary can line up along the
corfidi vector (250-270 degrees) then training of storms are
possible. Due to the very high PWs, rainfall rates will be quite
high tomorrow.

For potential QPF amounts, latest REFS shows amounts over 2.5+
possible.

The forcing will move east of the area by early morning
Tuesday ending the threat for showers and thunderstorms.

For Tuesday and Wednesday, besides some isolated storms across the
far east Tennessee Mountains and southwest North Carolina, surface
ridging and drier airmass will produce dry conditions.

For Thursday, increasing moisture and instability will produce an
chance of mainly terrain afternoon and evening storms.  Most of the
valley will remain dry but isolated storm possible.

For Friday and Saturday, a northern stream short-wave will pull a
frontal boundary into the southern Appalachians increasing the
threat of showers and thunderstorms, especially during the afternoon
and evening hours.

For next Sunday, upper ridge will build back into the region with
the frontal boundary lifting north. Coverage of storms will decrease
but still scattered mainly afternoon and evening convection
expected.

&&

.AVIATION...
(12Z TAFS)
Issued at 735 AM EDT Mon Jun 22 2026

Low VFR to MVFR cigs will continue for a few hours this morning.
Showers and storms will increase in coverage this afternoon. MVFR
to IFR conditions cannot be ruled out, along with frequent
lightning, under the strongest storms. Rain gradually wanes west
to east midnight through the the overnight, but MVFR to IFR cigs
may build back into the region among the saturated boundary layer.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             85  69  84  65 /  80  80  10   0
Knoxville McGhee Tyson Airport, TN  83  67  82  62 /  90  90  20   0
Oak Ridge, TN                       83  66  83  61 /  90  70  10   0
Tri Cities Airport, TN              84  64  80  55 / 100  90  30   0

&&

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

$$

DISCUSSION...DH
AVIATION...KRS