Chatta, Tennessee Weather Forecast Discussion

477
FXUS64 KMRX 191743
AFDMRX
Area Forecast Discussion
National Weather Service Morristown TN
143 PM EDT Fri Sep 19 2025
...New DISCUSSION, AVIATION...
.KEY MESSAGES...
Updated at 1216 PM EDT Fri Sep 19 2025
-  Above normal temperatures will persist through early next
    week.
-  Most locations will be rain free for the weekend, but there
    will be isolated to scattered showers and storms especially
    over the higher terrain.
-  Chances for showers and storms will trend upward by the
    middle and latter portions of the work week.
&&
.DISCUSSION...
Issued at 1216 PM EDT Fri Sep 19 2025
The remainder of today will continue to be rather quiet outside
of an isolated showers or storm across the eastern terrain, and
tonight will be dry.
The upper ridge that has been over our area will be pushed off to
our northeast by a short wave trough Saturday.  While moisture will
be limited, steepening lapse rates will result in more significant
convective energy than recent days. HREF mean MUCAPES values are
generally around 1000-1500 J/kg Saturday afternoon.  While shear is
weak, model sounding show DCAPE values hovering near 1000 J/kg. This
suggests a few of the strongest updrafts of the day could produce
wind gusts up to 40 mph, although convective energy still looks
likely to be low enough across the area to minimize any severe
threat. Will keep the low probability wording in the HWO for
Saturday.
Upper flow will be more quasi-zonal for Sunday into the first part
of the week, and temperatures will continue to run above normal
during this period. Models show weak short waves in the flow that
will enhance convection chances during the early part of the week.
We will have low chances for isolated to scattered showers and
storms in the forecast each day for Sunday through Tuesday, with a
slight increasing Pop trend during this period. By mid to late
week, models have been showing an upper low approaching from out
west or northwest, although there is poor agreement in all of the
details (timing, depth, location, etc.) of this upper low as is
usually the case with these types of systems, leading to low
confidence for any potential impacts. We will have higher chances
for showers and storms in the forecast for the Wednesday through
Friday period per the NBM.
&&
.AVIATION...
(18Z TAFS)
Issued at 1216 PM EDT Fri Sep 19 2025
Fog development late tonight is possible but looks unlikely, so
will have a VFR forecast all sites for the period along with light
winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             64  91  65  90 /  10  20  10  10
Knoxville McGhee Tyson Airport, TN  65  87  62  87 /   0  20  10  20
Oak Ridge, TN                       63  87  61  86 /   0  20  10  20
Tri Cities Airport, TN              59  85  58  83 /   0  20  10  10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DISCUSSION...99
AVIATION...99

NWS MRX Office Area Forecast Discussion