954
FXUS64 KMRX 021739
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
139 PM EDT Wed Jul 2 2025

...New SHORT TERM, LONG TERM, AVIATION...

.SHORT TERM...
(This evening through Friday)
Issued at 137 PM EDT Wed Jul 2 2025

Key Messages:

1. Mainly dry conditions through Friday, with the possible exception
of an isolated shower or thunderstorm in the TN mountains and
southwest North Carolina.

2. Slightly above normal temperatures but fairly comfortable
humidity levels Thursday and Friday.

Discussion:

A drier air mass has filtered into the area behind yesterday`s
frontal passage. Last night`s fog is not expected to be repeated
tonight, given the lower dewpoints we are seeing this afternoon
compared to 24 hours ago, and the lack of afternoon/evening
showers today compared to yesterday. Some patchy fog may be
possible near area rivers and lakes, but probably not much outside
of those areas.

Thursday and Friday will have nice conditions for outdoor
activities and Fourth of July celebrations. We will have a
mid/upper level ridge building across the region, with a generally
N to NE flow through the column. Subsidence under the ridge will
warm temperatures into the upper 80s to lower 90s both days (maybe
mid 90s around CHA on Friday), but humidity levels should be
tolerable for this time of year, with dewpoints dropping into the
60s in the afternoons. The only chance of rain will be in the TN
mountains and higher elevations of SW NC Friday afternoon, with
coverage expected to be isolated at best as the upper ridge and
dry air entrainment will suppress convection.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 137 PM EDT Wed Jul 2 2025

Key Messages:

1. Thunderstorm chances increase slightly this weekend, but the
overall chance of precipitation remains very low (less than 20
percent) and mainly in the mountains.

3. Increasing temperatures and humidity this weekend with heat index
values approaching 100 near Chattanooga.

4. Rain chances increase next week for the entire area, but details
remain uncertain.

Discussion:

The upper-level ridge shifts east of our area over the weekend, with
weak troughing near the MS Valley region. This will bring a return
of weak southerly flow and increasing moisture and humidity.
Afternoon thunderstorm chances will begin to increase, mainly across
the mountains. With highs in the lower to mid 90s and dewpoints
in the southern TN Valley rising into the lower 70s, some
locations near CHA may approach 100 degree heat index Saturday and
Sunday.

By early next week, we will be in between two synoptic systems:
troughing across the Great Lakes and upper Mississippi Valley, and a
tropical low pressure system near Florida. There is still quite a
lot of uncertainty with the placement of these systems and how it
will impact our weather, but the most likely outcome at this time is
increasing chances of diurnal afternoon thunderstorms each day
across our forecast area.

&&

.AVIATION...
(18Z TAFS)
Issued at 137 PM EDT Wed Jul 2 2025

VFR conditions are forecast for this TAF period. Fog cannot be
completely ruled out tonight, but dewpoints this afternoon are lower
than yesterday at this time, and we don`t expect any
afternoon/evening showers to increase low level moisture.
Therefore, fog will be left out of this TAF set.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             69  91  69  94 /   0   0   0  10
Knoxville McGhee Tyson Airport, TN  67  91  67  93 /   0   0   0  10
Oak Ridge, TN                       66  91  67  93 /   0   0   0  10
Tri Cities Airport, TN              64  86  63  90 /   0   0   0  10

&&

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

$$

SHORT TERM...DGS
LONG TERM....DGS
AVIATION...DGS