063
FXUS64 KMRX 130203
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1003 PM EDT Wed Jun 12 2024

...New UPDATE...

.UPDATE...
Issued at 1000 PM EDT Wed Jun 12 2024

Minor tweaks to grids, and updated zones to remove evening
wording. No change of substance, just cosmetics. Cirrus is
thinning and moving east, so expect a great weather night.

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 258 PM EDT Wed Jun 12 2024

Key Message:

1. Warming trend continues as above normal temperatures are expected
Thursday afternoon.

Discussion:

Weak disturbances aloft continue to promote high level cirrus across
the Tennessee Valley, though high pressure and associated subsidence
keep the region free from any developing diurnal activity. High
clouds are expected to gradually depart tonight into early Thursday.

The aforementioned high pressure center shifts east Thursday. We
will remain along the western fringe as a subsidence inversion still
remains in model derived soundings, albeit, weaker than the past few
days. Given this weakening subsidence, isolated showers and storms
cannot be ruled out in higher elevations of the East Tennessee
mountains but most will remain dry once again. SPC HREF suggest
MUCAPE generally struggles to reach 1000 J/kg. Main focus will be
continued warming trend with afternoon temperatures approaching the
upper 80s to low 90s in portions of the central in southern valley.
We will remain well below advisory level criteria for heat indices,
however, it is still good to keep heat safety practices in mind. If
working or spending time outside make sure to stay hydrated, wear
light colored and loose fitting clothing, and take frequent breaks
in shaded or cooled areas.

&&

.LONG TERM...
(Thursday night through next Wednesday)
Issued at 258 PM EDT Wed Jun 12 2024

Key Messages:

1. Temperatures rising through the weekend with well above normal
temperatures by Sunday.

2. Chances for showers and thunderstorms will be higher for Monday
through Wednesday.

Discussion:

We start the period with a weak cold front approaching from the
northwest, and this front is forecast to move through our area later
Friday into Friday night.   Moisture and convective energy look low,
but there may be a few showers mainly north and mountains Friday
afternoon. No significant cooling will occur behind this weak front,
and  models are in good agreement that a high amplitude upper level
ridge will be building in from the west during the weekend.
Temperatures will be increasing, and by Sunday afternoon will likely
be well above normal with highs in the 90s over most locations
outside of the higher terrain. Humidity will be increasing as well,
so heat index values are expected to approach 100 Sunday afternoon
across portions of the southern and central valley.  Most areas will
be dry for the weekend, but there may be limited convection coverage
in the afternoon especially over the eastern mountains Sunday.

Models generally agree that the upper ridge will continue into mid
week over the eastern US, but differ on the exact location as well
as how quickly moisture returns on the backside of this ridge as its
axis shifts to our east. It does appear that there will be higher
chances for showers and storms for the Monday through Wednesday time
frame especially if the further east axis for the ridge shown by
some of the models is realized, and the better chances will be in
the afternoon hours as is typical with summer-time convection.
Temperatures are expected to continue to be above normal for Monday
through Wednesday, but likely slightly lower overall than Sunday
assuming the additional clouds and convection are present.

&&

.AVIATION...
(00Z TAFS)
Issued at 721 PM EDT Wed Jun 12 2024

VFR conditions and light winds continue. Wind direction is
expected to become southwesterly (southerly at CHA) will remain
less than 10kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             67  92  70  94 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  64  89  67  90 /   0  10   0  10
Oak Ridge, TN                       63  89  67  91 /   0  10   0  10
Tri Cities Airport, TN              62  87  62  88 /   0  10   0  10

&&

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

&&

$$

SHORT TERM...GC
AVIATION...GC