Johnson City, Tennessee 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

588
FXUS64 KMRX 061104 AAA
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
704 AM EDT Sun Jul 6 2025

...New AVIATION...

.SHORT TERM AND LONG TERM...
(Today through Saturday)
Issued at 132 AM EDT Sun Jul 6 2025

Key Messages:

1. Hot and mostly dry again today.

2. Monday into Tuesday we transition from a dry pattern, to one
increasingly more conducive for afternoon shower and thunderstorm
activity that lasts through the forecast period.

Discussion:

The entirety of the forecast can be boiled down to a battle
between troughing over the Great Lakes and Ohio valley, and the
subtropical ridge attempting to build back this direction from the
Gulf. It appears the troughing will win out, with rain chances
increasing through the week as a result and temperatures hanging
right around normal for this time of year.

Tropical Storm Chantal will move north from the South Carolina
coast this morning to central Virginia by this evening, ahead of a
shortwave moving into the Ohio valley. Locally we should remain
dry most everywhere but an isolated shower or two could occur in
the higher terrain. Afternoon highs will run a couple of degrees
above normal once again today.

Monday onward the aforementioned troughing will exert increasing
influence over the weather in the southern Appalachians, primarily
through weakening the ridge aloft and allowing for more afternoon
shower and thunderstorm activity. Monday should be a transition
day, with more activity over the higher terrain and some
increasing chances for storms to move into the valley by late
afternoon or early evening. For Tuesday onward, troughing to our
north becomes more pronounced, and expect a general increase in
rain chances across the board along with near normal temperatures.
The only caveat here is that NBM guidance is very aggressive with
rain chances, showing likely to even categorical PoPs into the
lower elevations by week`s end. Pattern wise, there`s support for
this as the troughing over the Great Lakes and Ohio valley region
lays out a stationary boundary to our north and also draws
moisture northward from the Gulf into the southern Appalachian
region. While this pattern will favor increased convective
coverage, I`m not sure such high PoPs in the NBM are warranted
for lower elevations. I toned down the rain chances in the TN
valley Mon and Tue, but let the NBM ride thereafter. Time will
tell if additional adjustments are needed in the lower elevations
for mid to late week.

&&

.AVIATION...
(12Z TAFS)
Issued at 702 AM EDT Sun Jul 6 2025

VFR conditions will prevail through the period. Some ISOLD
SHRA/TSRA may develop over the Appalachians or over the Cumberland
Plateau today but coverage will be sparse and won`t affect any
terminals. Winds will be light and variable.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             95  73  96  74 /  10  10  20  10
Knoxville McGhee Tyson Airport, TN  93  72  93  72 /  10  10  20  10
Oak Ridge, TN                       93  71  93  71 /  10  10  30  10
Tri Cities Airport, TN              89  67  90  69 /  10  10  20  20

&&

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

$$

SHORT TERM...CD
LONG TERM....CD
AVIATION...CD