313
FXUS64 KMRX 121739
AFDMRX

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

...New AVIATION...

.UPDATE...
Issued at 1039 AM EDT Wed Jun 12 2024

Satellite observations show an area of high cirrus atop the
Tennessee Valley this morning. This is expected to continue
through the remainder of the day, though it is not expected to
impact the warming trend to near normal temperatures. The
inherited forecast remains in good shape. The only change was to
omit morning wording out of the zone forecast product.

&&

.SHORT TERM...
(Today and tonight)
Issued at 250 AM EDT Wed Jun 12 2024

Key Messages:

1. A warming trend is expected through the week.

Discussion:

Currently, satellite and area observations show a good deal of
high level clouds moving across much of the area. Also, an area of
5-6kft broken clouds over northeast Tennessee. Expect a good deal
of high clouds to remain with scattered/few lower clouds cover
producing an overall partly sunny day.

Dry air mass will allow temperatures to warm nicely today close to
near normal.

For tonight, plenty of high clouds remain. Overall, persistence
weather pattern with surface ridging and weak west/northwest flow
aloft.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 250 AM EDT Wed Jun 12 2024

Key Messages:

1. Above normal temperatures and rising humidity through the
weekend.

2. Increasing rain chances possible Monday-Tuesday but model
differences lead to low confidence.

Discussion:

At the start of this period, surface high pressure centered off the
Mid-Atlantic coast will extend SW across much of the Southeast,
while in the mid/upper levels, a large ridge will be over the
southern Plains and southern Rockies. A broad trough will be
crossing the Great Lakes, pushing a cold front into the OH Valley.

A few isolated showers or storms are possible in the mountains
Thursday afternoon with daytime differential heating and little
capping. On Friday the cold front will move into KY with a slight
southward dip of the midlevel trough. Convection with the front will
be weakening as it nears our area, and will have just a slight
chance PoP in the afternoon for SW VA. The front will stall near our
northern counties, with the main impact being lower dewpoints on
Saturday. The large ridge over the Plains will be shifting eastward
on Saturday, which should suppress convective potential and bring
high temps in the 90s for the TN Valley. Sunday will have the
highest heat indicies, with the ridge aloft over the region and a
southerly low level flow increasing moisture. Southern and central
Valley areas may exceed 100 heat index in the afternoon.

The potential for showers and thunderstorms increases on Monday and
Tuesday as the ridge axis shifts east of the Appalachians. The exact
position of the ridge will determine our rain chances, and the
models are not in good agreement with this. The GFS has a large
plume of Gulf moisture across MS/AL and Middle/West TN, while the
ECMWF keeps this moisture along and west of the MS River. For now,
will cut back the NBM PoPs a little, and have chance PoPs in the
western half and slight chances east both days.

&&

.AVIATION...
(18Z TAFS)
Issued at 136 PM EDT Wed Jun 12 2024

VFR conditions and light winds continue. For tomorrow afternoon,
wind direction is expected to veer to a more westerly(Southerly at
CHA) flow but will remain less than 10kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             67  92  69  95 /   0  10   0   0
Knoxville McGhee Tyson Airport, TN  64  89  67  92 /   0  10   0  10
Oak Ridge, TN                       63  89  66  92 /   0  10   0  10
Tri Cities Airport, TN              60  87  63  88 /   0  10   0  10

&&

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

$$

SHORT TERM...DH
LONG TERM....DGS
AVIATION...KRS