-- Discussion containing changed information from previous version are highlighted. --
415
FXUS64 KMRX 042314
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
714 PM EDT Tue Jun 4 2024

...New AVIATION...

.SHORT TERM...
(This evening through Wednesday)
Issued at 203 PM EDT Tue Jun 4 2024

Key Messages:

1. Showers and thunderstorms will be more isolated overnight and
into the early morning hours.

2. Scattered to numerous showers and storms are expected Wednesday
afternoon and evening. Cannot rule out a few strong storms with
locally gusty winds or heavy downpours but overall, general
thunderstorm activity will be predominant.

Discussion:

Shower and thunderstorm activity has increased the past couple of
hours. With low shear and low to moderate CAPE expected this
afternoon, a few strong storms will be possible but severe
potential will be low. In the upper levels, a shortwave moving out
of IL/MO into the Ohio Valley is bringing enhanced activity to the
region this afternoon and evening. Activity will be more isolated
in the overnight and early morning hours. Tomorrow, a trough
stretches from the Ohio Valley to Arkansas/West Tennessee. This
will bring another round of showers and storms to the region
starting in the morning for the Cumberland Plateau and Southern
Tennessee Valley and spreading areawide in the afternoon hours.
With low deep layer shear and moderate CAPE tomorrow afternoon,
some strong storms are likely and a few severe storms will be
possible but widespread severe weather is not expected.

Some patchy fog is possible in the early morning hours but
lingering cloud cover overnight will limit fog potential.
Southwesterly winds will increase slightly tomorrow ahead of a
cold front that will stay to our west through this forecast
period.

&&

.LONG TERM...
(Wednesday night through next Tuesday)
Issued at 203 PM EDT Tue Jun 4 2024

Key Message:

1) Drier and cooler Friday into Sunday behind the front.

2) Poor agreement in models from Sunday onward, with a boundary over
the southeastern US.

Discussion:

By Wednesday night we`ll likely see another round of storms move
through as the frontal boundary finally pushes through the southern
Appalachian region heading into the overnight hours. Some storms
could last into sunrise on Thursday, but many people should be
fairly dry for Thursday as the drier air from the northwest begins
to move in.

Cooler and drier conditions will likely persist for most people
Friday and Saturday with daytime highs staying just below seasonal
normals and dew point values only in the 50`s meaning it should be
a generally pleasant weekend.

Shower and thunderstorm chances will make a return to the region by
late Sunday as a weak shortwave dives through the Tennessee Valley.
Somewhat uncertain on where the best dynamics with this quick moving
system will be, but it looks likely it will be somewhere in the
Tennessee/Ohio Valley Sunday into Monday.

Once we move into next week things become much more unclear as
stationary boundary looks to strengthen convergence somewhere in the
southeastern United States. Most models are keeping the focus of
enhanced thunderstorm activity with this system somewhere between
the Tennessee Valley and the Gulf Coast. Will keep moderate
precipitation chances in the forecast, but hopefully long range
models come into better agreement to increase confidence on where
this boundary sets up.

&&

.AVIATION...
-- Changed Discussion --
(00Z TAFS)
Issued at 709 PM EDT Tue Jun 4 2024

The main aviation impact this evening will be showers and storms
that will affect TYS more than the others. Overnight into the
morning hours, additional showers and isolated storms are
possible, first impacting CHA before moving northeastward towards
the other terminals. Overall, TYS is most likely to see fog
development by the early morning with the other two sites likely
to stay VFR. Throughout the day, a more persistent southwesterly
wind will be noted with gusts to 20 kts possible at TYS. This will
also be in the presence of additional showers and storms during
the afternoon hours. By late afternoon, it is more uncertain how
much activity will linger.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Chattanooga Airport, TN             68  87  69  88 /  50  70  80  20
Knoxville McGhee Tyson Airport, TN  67  83  68  85 /  60  80  90  30
Oak Ridge, TN                       67  82  68  86 /  50  80  90  20
Tri Cities Airport, TN              65  82  66  82 /  40  80  80  30
-- End Changed Discussion --

&&

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

$$

SHORT TERM...McD
AVIATION...BW