Johnson City, Tennessee 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

620
FXUS64 KMRX 261125
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
725 AM EDT Tue May 26 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 713 AM EDT Tue May 26 2026

- Periods of scattered rain and thunderstorms to continue. A
complete wash out is not expected, but low potential for flooding
still continues, especially as total rainfall begins to pile on.

- Rain chances remain generally elevated until this weekend, when
  finally a drier airmass from the north may be able to replace
  the stagnant and saturated weather pattern.&&

.DISCUSSION...
Issued at 134 AM EDT Tue May 26 2026

The drum beat of daily rain chances in the war against drought
continues. CAMs have another day of scattered showers and
thunderstorms during the mid afternoon and evening hours again
today. Despite the moist airmass and another day of scattered
storms, I`m not sold on the need for another day of a large scale
flood watch here. Heavy rainfall amounts the past 24 hours were once
more isolated in nature, and while flash flooding is again possible,
the continued isolated nature of the bouts of heavy rain makes a
massive watch seem too broad an instrument. There`s also no
guarantee that those who saw rain yesterday see rain again today or
tomorrow. Mean wind vectors in the atmosphere should allow for
storms to keep steady motions, and not sit and dump on any one town
for too long. There`s some weak low level shear present today, with
the HRRR painting light helicity tracks across the region. Better
shear is present in Kentucky, and while we may see transient
rotation in more mature cells later, not expecting a severe threat
today.

After today, we have a few more days of high moisture just pooling
over the Mid South region, with generally light forcing dynamics
continuing. The front looks to move slightly further north into
Kentucky but generally remain stationary. By Friday the front moves
to our south, though some models (such as the Euro) keep things
stationary and close enough on our southern side through the weekend
to warrant low PoPs. Should the front make it a little further
south, as the GFS depicts, then the weekend may be drier for all.

From the weekend onwards into early June the longer range ensembles
bring about a drying out period, with the EPS mean PWAT dropping to
1" or less next week. This should give everyone an opportunity to
deal with outdoor chores, and a time for locations to dry out once
more.

&&

.AVIATION...
(12Z TAFS)
Issued at 713 AM EDT Tue May 26 2026

VFR conditions are present across the region with the exception of
MVFR CIGs at CHA this morning. Low CIGs at CHA will lift by mid to
late morning. Shower activity will increase late this morning,
becoming widespread in the afternoon and evening hours. Confidence
in thunderstorm development is higher today for the afternoon/early
evening hours. Showers and storms are expected to taper off after
sunset this evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             80  67  82  66 /  70  50  60  50
Knoxville McGhee Tyson Airport, TN  81  66  82  65 /  80  50  80  70
Oak Ridge, TN                       80  65  81  64 /  80  50  80  60
Tri Cities Airport, TN              82  63  80  62 /  70  50  70  90

&&

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

$$

DISCUSSION...Wellington
AVIATION...McD