285
FXUS64 KMRX 131936
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
336 PM EDT Tue Aug 13 2024

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

.SHORT TERM...
(This evening through Wednesday)
Issued at 257 PM EDT Tue Aug 13 2024

Key Messages:

1. Slightly below normal temperatures tonight and near normal
temperatures tomorrow.

2. Mostly dry through Wednesday.


Discussion:

Overall, same story different day. We remain in a northwest flow
pattern with troughing to our northeast and an upper level ridge
axis to west-northwest. Outside of a slight chance for a shower or
storm across the northeast TN mountains, all areas will be dry
through tonight. Also, slightly below normal low temps will be in
place again tonight due to the dry air that remain in place.

Tomorrow, mostly dry weather continues as high pressure shifts
further east and the ridge becomes centered over the eastern U.S.
Slight chance for an afternoon shower or storm across southwest NC
and the east TN mountains.

&&

.LONG TERM...
(Wednesday night through next Tuesday)
Issued at 257 PM EDT Tue Aug 13 2024

Key Messages:

1. Mostly dry weather Thursday. Warmer Friday with increasing
chances of showers and storms heading into the weekend.

2. Cold front forecast to cross the area sometime on Saturday with
possibly drier conditions to finish off the weekend and start the
new work week.

Discussion:

Troughing setting up across the northern tier of the U.S. by
Thursday will feature three upper lows; along west coast, over the
Upper Plains and over the Canadian Maritimes. The one furthest east
will steer Ernesto over open waters in the coming days, while the
closed low yet to form over the Upper Plains/Upper Mississippi
Valley, will bring us increased chances for showers and
thunderstorms by the weekend. Before that happens, Thursday should
be mostly dry with any activity confined to the higher terrain.
Friday appears will be the warmest day when SWly flow is at its
height ahead of the approaching front. Precipitation will increase
from the west and northwest, the best chances headed into Saturday.

As noted in this morning`s discussion, an eye will be kept on the
time period of frontal passage, as CAPE up to 1500 J/kg is possible
as well as an increase in effective shear. SPC currently isn`t
confident on a 15% anywhere this far out due to convergence along
the front may not be as strong and antecedent convection hampering
severe potential.

To finish the period, temperatures will fall back into the 80s in
the valley and chances for precipitation may linger. Longwave
troughing will move to the northeast, allowing ridging to build out
west. Our area will remain under northwesterly flow with weak
disturbances supporting development, but the further out in time,
the greater the uncertainty of coverage and timing.

&&

.AVIATION...
(18Z TAFS)
Issued at 121 PM EDT Tue Aug 13 2024

VFR conditions through the period at all sites with light
northerly winds at CHA and TYS with VRB at TRI. A few data sources
showing fog at TRI tonight but low confidence so will not include
in this TAF set.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             67  90  70  91 /   0   0   0  10
Knoxville McGhee Tyson Airport, TN  65  89  66  89 /   0   0   0  10
Oak Ridge, TN                       65  88  66  89 /   0   0   0  10
Tri Cities Airport, TN              61  86  62  86 /   0  10   0  10

&&

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

$$

SHORT TERM...
LONG TERM....KS
AVIATION...