945
FXUS64 KMRX 200513
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
113 AM EDT Sun Apr 20 2025

...New AVIATION...

.UPDATE...
Issued at 821 PM EDT Sat Apr 19 2025

Tonight will be dry and mild. No significant changes were made to
the forecast for tonight during the evening update. Dew points
were a few degrees higher than forecast and I increased them a bit
overnight as new guidance suggests.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 311 PM EDT Sat Apr 19 2025

Key Message:

1. Continued dry weather and near record warm temperatures are
expected.

This Evening/Tonight

Currently this afternoon, a trough/closed low is centered along and
just east of the Rockies with impressive ridging across the eastern
U.S. At the surface, Bermuda High Pressure continues across the
Atlantic with a frontal boundary near the Ohio River Valley.
Locally, 500mb heights are around 5,880m, which is a normal value
during the middle of Summer. This has also been combined with broad
southwesterly flow in the lower levels, promoting impressively warm
temperatures. This overall trend will continue into the overnight
hours with a decrease in winds after peak mixing and a fairly weak
MSLP gradient.

Easter Sunday

For Easter Sunday, the aforementioned closed low will deepen and
eject further eastward towards the Mississippi River Valley. This
will lead to some height falls locally but also the development of a
low pressure system expected to track northward into the upper
Mississippi River Valley. While some height falls are expected, more
broad southerly flow will continue unseasonably warm, summer-like
temperatures. Some weak moisture advection will likely improve
afternoon RH`s, but values around 35 percent are still likely.
The following lists record high temperatures for the day, which
would also near the highest for Easter, which falls on different
dates:

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
04-20   89(2002)       87(2002)       85(2023)       88(2002)

&&

.LONG TERM...
(Sunday night through next Saturday)
Issued at 311 PM EDT Sat Apr 19 2025

Key Messages:

1. A weakening front will bring showers and storms to the area
Monday into Monday night. Some stronger storms are possible, but the
severe risk is very limited.

2. Warm temperatures continue for the rest of the period with
chances for showers and storms each day.

Sunday Night through Wednesday

At the start of the period, the system referenced in the short term
period will be tracking into the Upper Mississippi River Valley with
previous ridging shifting further east. This will also have pulled
the recent frontal boundary northward, creating a broad warm sector
in the east. The cold front associated with this system is expected
to approach from the west by Monday. At this time, the stronger jet
dynamics and moisture transport look to remain north and west.
Instability of around 500 J/kg by the afternoon will support
convection, especially if the current timing is maintained. The wind
profiles suggest reasonable deep-layer shear of 35 to 40 kts, driven
mainly by speed. With all things considered, some stronger storms
can`t be ruled out. But, the overall setup and distance from upper-
level support will be a hindrance to severe weather. Similar
messaging will be kept as the 30 to 35 kt winds at 850mb could be
brought down to the surface.

By Tuesday, the frontal boundary will move into the area but be
weakened from Monday with a weak area of high pressure also noted to
our north. This will continue chances for rain, especially further
south. By Wednesday, another shortwave will approach from the west
with this frontal boundary being pulled further north. This will
lead to increased moisture and continued chances for convection. By
this time, winds at all levels will be weakened, meaning daytime
heating and thermodynamics will be the main support for convection,
more typical of the summer.

Thursday through Saturday

By Thursday, the overall pattern remains similar with another
shortwave keeping the chances for thermodynamically-driven
convection, especially along the higher terrain. Late in the week
and into the weekend, additional shortwaves are expected to track
over the region with general southwesterly flow continuing aloft.
This will keep chances for diurnal convection in the forecast each
day. As moisture will be sufficient, the main question for intensity
will be how much surface heating occurs each day.

&&

.AVIATION...
(06Z TAFS)
Issued at 112 AM EDT Sun Apr 20 2025

VFR and dry conditions expected to continue tomorrow. A gust 15
to 20 knots tomorrow cannot be ruled out, especially at KCHA, but
generally light winds will be predominant through the period.
Otherwise mainly high clouds, a few puffy cumulus clouds during
the afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             87  63  84  63 /   0   0  40  70
Knoxville McGhee Tyson Airport, TN  85  64  84  62 /  10   0  40  70
Oak Ridge, TN                       85  63  81  61 /  10   0  50  70
Tri Cities Airport, TN              83  59  83  59 /  10   0  20  70

&&

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

$$

SHORT TERM...BW
LONG TERM....BW
AVIATION...Wellington