513
FXUS64 KMRX 251131
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
731 AM EDT Fri Jul 25 2025

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 135 AM EDT Fri Jul 25 2025

Key Messages:

1. Dry through sunrise. Isolated showers and storms this afternoon,
mainly focused along the Cumberland Plateau and east TN mountains.

2. Hot and humid conditions continue, with afternoon Heat Indices
near 100 for most areas, expect for northeast TN and southwest VA
where mid 90s will be more common.

Discussion:

Through sunrise, not expecting too much fog as it was mostly dry
today. The best chances for any fog develop will be across Wise
County VA, where showers developed yesterday evening.

Otherwise, not a lot to talk about, it`s July and it`s hot. Upper-
level ridge continues to dominate across the region. This translates
to high temps in the 90s and Heat Indices near 100 for most areas.

Due to the strength of the ridge, any convection will mostly be
limited to the Cumberland Plateau and the east TN mountains. Most
valley locations will stay dry, although an isolated shower or storm
is still possible.

Mostly dry tonight. Any area that receives rainfall today will
likely see some patchy fog overnight. Otherwise, fog isn`t a concern.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 135 AM EDT Fri Jul 25 2025

Key Messages:

1. Ridging dominates through Tuesday, keeping us hot and mostly dry.
Heat Indices around 100 to low 100s are expected through this time.

2. Weak cold front and weakness in the ridge may bring increasing
scattered convection to the region towards the middle of next week.

Discussion:

The upper ridge is centered to our southeast on Saturday and then
retrogrades to the west through Tuesday. Expect mostly dry
conditions through this time, outside of any terrain driven,
diurnal, activity. However, as the high pushes further west,
southwest VA may have see some slightly higher precip chances Sunday
night into Monday as they will be in a northwest flow patter. This
would allow any impulses moving around the northern periphery of the
ridge to ride down into these areas.

As with the previous forecast, this anomalous ridging will be near
the max of climatology according to NAEFS forecast percentiles. High
temp records unlikely to be broken but we will not be too far off.

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
07-24   101(1952)      101(1934)      97(2016)       98(1993)
07-25   101(1952)      101(1934)      98(2016)       97(2016)
07-26   103(1993)      99(1993)       96(2016)       100(1993)
07-27   104(1952)      103(1952)      99(1952)       102(1952)
07-28   106(1952)      103(1952)      102(1952)      105(1952)
07-29   105(1952)      101(1952)      102(1952)      103(1952)
07-30   99(1999)       98(1995)       96(1995)       100(1995)
07-31   99(1999)       99(1915)       95(1995)       100(1995)

Heat index values from Saturday through mid-week will likely be in
the lower 100s for much of the forecast area, especially across the
southern valley between Chattanooga and Knoxville.

By mid-week, the ridge flattens as an upper trough a cold front push
down from out of the Ohio River Valley. This will open the door for
some higher precip chances from mid-week onward. This is assuming
that the trough is strong enough to flatten the ridge. Uncertainty
remains high on whether or not this will occur. If it doesn`t, look
for continued low precip chances with Heat Indices remaining in the
low 100s.

&&

.AVIATION...
(12Z TAFS)
Issued at 728 AM EDT Fri Jul 25 2025

Persistence forecast with low chances for precipitation/thunder
during the PM hours. Light or variable winds during peak heating
with mid to high level clouds, transitioning to calm conditions
and nearly SKC or high level clouds overnight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             93  73  94  75 /  30  10  30   0
Knoxville McGhee Tyson Airport, TN  93  74  94  75 /  40  10  30  10
Oak Ridge, TN                       93  73  94  74 /  40  10  40  10
Tri Cities Airport, TN              91  71  91  72 /  20  10  50  20

&&

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

$$

AVIATION...KS