324
FXUS64 KMRX 261115
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
715 AM EDT Sat Jul 26 2025

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 222 AM EDT Sat Jul 26 2025

Key Messages:

1. A few isolated showers and storms.

2. Heat index values in the lower 100s for the central and southern
TN Valley. Below Heat Advisory criteria, but dangerous heat,
nonetheless.

Discussion:

A strong 596 dam high remains in place to our southeast, centered
across South Carolina. A tropical like airmass remains as well as we
are on the western periphery of the high, allowing gulf moisture to
stream into our area. PW values remain elevated at 1.9 to 2 inches,
which is around the 90 percentile based on BNA sounding climatology.
The hot and humid air will allow Heat Indices to climb into the
lower 100s this afternoon for much of the central and southern TN
Valley. Heat Indices in the low to upper 90s expected across
northeast TN and southwest VA.

A few isolated showers and storms are once again expected today, but
mainly focused along our high terrain locations. This includes areas
such as the Cumberland Plateau and east TN mountains. With a little
stronger subsidence in place today, coverage should be less compared
to Friday afternoon. Also, with virtually no shear in place, any
storm that goes up will quickly come down (summer-time pulse). Heavy
rainfall and brief gusty winds possible with any storms that develop
today.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 222 AM EDT Sat Jul 26 2025

Key Messages:

1. Hot through middle of next week. Near Heat Advisory criteria on
Sunday through early week.

2. Limited convection Sunday, slightly better chances Monday and
Tuesday, even higher chances midweek and onward.

Discussion:

As with the previous forecasts, the ridge will continue to
retrograde westward into Monday and Tuesday. Sunday`s precip chances
slightly higher than Saturday as the flow becomes more zonal. By
Monday we are on the eastern periphery of the high and in northwest
flow. This will allow for another slight increase in precip chances
compared to the previous days, especially across northeast TN and
southwest VA. This is due to a few weak vorticity impulses
traversing through the 500 mb flow around the northern periphery of
the high. By Tuesday, the high pushes even further west and we are
under northerly flow. This will leave the door open for additional
chances for scattered showers and storms. Heat Indices will remain
elevated through this time, and will approach Advisory criteria.

By the middle of the week, we are still looking at the possibilty of
the ridge flattening as a cold front approaches from the north. If
the front can push far enough south, precip chances will be on the
increase by midweek and onward areawide.  is a signal for a weakness
in the ridge with a slow moving cold front shifting south towards
the region by mid to late week. Confidence remains low on the
southern extent of this front.

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
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)
08-01   99(2010)       97(1935)       95(1953)       97(1954)

&&

.AVIATION...
(12Z TAFS)
Issued at 709 AM EDT Sat Jul 26 2025

Following calm conditions this morning and light showers east of
TRI, winds will be light out of the SW along with mid to high
clouds. Another calm night can generally be expected into Sunday
morning with VFR prevailing for all.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             93  75  96  76 /  30  10  30  10
Knoxville McGhee Tyson Airport, TN  94  75  94  76 /  30  10  30  20
Oak Ridge, TN                       93  73  94  75 /  30  10  30  20
Tri Cities Airport, TN              92  71  91  71 /  30  20  40  30

&&

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

$$

SHORT TERM...
AVIATION...KS