013
FXUS64 KMRX 060005 AAA
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
705 PM EST Wed Feb 5 2025

...New AVIATION...

.SHORT TERM...
(This evening through Thursday)
Issued at 257 PM EST Wed Feb 5 2025

Key Messages:

1. Very warm with scattered to numerous showers with a few
thunderstorms.

2. A strong to severe storm is possible tonight into Thursday mainly
along and near the northern Plateau/SW VA, and isolated flooding
will also be possible mainly SW VA.

.Discussion...

A weak nearly stationary boundary is located to our south, and flow
aloft is nearly zonal across the area.  Shortwave energy aloft
moving through the zonal flow will induce a weak surface wave along
the front to our west that will lift northeast, and the front to
our south will move north as a warm front into our area overnight
into Thursday before a weak cold front sags southeast toward our
area late in the day Thursday. It will continue to be quite warm for
the short term period, with highs Thursday approaching (or possibly
exceeding at CHA) the record highs for the day.

The southwesterly low level jet will increase overnight across our
area and continue into Thursday, with 850mb winds reaching speeds in
the 40 to 50kt range. Some gusty winds can be expected in the higher
terrain, but direction is not favorable for mountain wave
enhancement so speeds should generally stay below the wind advisory
threshold. Given the strong shear associated with the low level jet,
there is the possibility of a few isolated strong to severe storms
mainly along and near the northern Plateau and into SW VA tonight
and Thursday. Models including the HREF generally show MUCAPE values
are exceeding 500 J/kg across western/northern parts of the area,
but model soundings generally show it being elevated especially in
the valleys. Shear is very strong including the lowest levels as 0-
1km shear of 30 to 40+ kts is indicated later tonight into Thursday,
and rotation of any stronger updrafts appears likely.  The severe
threat right now looks very low over much of the area given the
limited instability that will likely be elevated in nature, but
along and near the northern Cumberland Plateau and SW VA there looks
to be better chance for more of the instability to become surface
based, so there is a marginal threat of severe thunderstorm winds,
hail, and even a very low but non-zero threat of a tornado. This
will be highlighted in the HWO.

The heaviest rainfall totals for the short term period look to be
across portions of SW VA (where current QPF values are generally
around an inch), and these areas are already quite wet so there is
the threat of isolated flooding as well.

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
02-06      70(2019)     73(1986)        68(1991)      70(2008)

&&

.LONG TERM...
(Thursday night through next Wednesday)
Issued at 257 PM EST Wed Feb 5 2025

Key Messages:

1. Warm temperatures continue into the weekend, then becoming more
seasonable.

2. Active pattern through the next week with multiple opportunities
for rain. There will be a potential for flooding, especially during
the Monday/Tuesday time frame.

Discussion:

We will remain in quasi-zonal flow in the upper levels for the long
term period.  Surface high pressure will build in for Friday with
some drying especially north and central. Temperatures will be a bit
cooler but still above normal Friday, then Saturday looks to be
quite warm as temperatures may make a run at the records for the
date.  Temperatures will trend back closer to normal again later in
the period.

Friday`s brief drying will be short-lived as a series of upper level
short waves will move across the area and frontal boundaries meander
across the region during the remainder of the period. The details
are still uncertain, but one weak wave and cold front will likely
bring showers to the area mainly Saturday/Saturday night with some
brief drying again Sunday, then a more potent system is forecast to
push the front back north and bring more significant rain to the
area sometime in the Monday/Tuesday time frame.  Models show the
frontal boundary stalling/moving slowly and while the details are
not clear about its exact location this far out, we will continue to
monitor this system closely as there is a potential for more
widespread flooding.

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
02-08     76(1937)       75(1937)      70(2001)       71(2009

&&

.AVIATION...
(00Z TAFS)
Issued at 659 PM EST Wed Feb 5 2025

High resolution guidance indicates coverage of incoming SHRA will
remain ISOLD to SCT through much of the overnight hours, with
more widespread convection expected towards daybreak across the
region. Trended the TAFs in that direction, favoring VCSH or
perhaps a brief period of SHRA before convection becomes more
widespread between 15-18z. Flight category wise, expect a downward
trend towards MVFR levels overnight as low level moisture
continues to stream northward into the area.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             74  59  71  54 /  30  50  50  90
Knoxville McGhee Tyson Airport, TN  70  58  69  49 /  30  60  70  90
Oak Ridge, TN                       69  57  66  47 /  30  80  70  90
Tri Cities Airport, TN              65  49  66  45 /  20  80  90  80

&&

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

$$

SHORT TERM...
AVIATION...CD