833
FXUS64 KMRX 201114
AFDMRX

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

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 331 AM EDT Sun Apr 20 2025

Key Messages:

1. Summer-like temperatures for Easter, dry weather expected, only a
5-10% chance of a shower or thunderstorm on the Cumberland Plateau.

Discussion:

A sweet treat is in store for the region with eggceptional weather
expected today as we`re stuck in between an anomalous ridge of high
pressure over the southeastern coast, and a digging upper trough
over the central US. The continued resulting southwesterly flow
paints another very warm day today, perfect for hunting Easter
eggs. Peak temperatures today will flirt with both the daily
record highs and the Easter record highs, dependent on how much a
role the cloud cover plays. Regardless of cloud cover, any
chocolate left inside vehicles will be prone to efficient melting.

The expectation is for dry weather to rule supreme today, though if
there were to be a random shower or thunderstorm, I think the most
likely location is on the Cumberland Plateau. Out of all the
meteorology models in our basket, the low-resolution global
ensembles are the most bullish on this idea. Meanwhile, taking a
peep at the CAMs shows they`re split, with the HRRR not showing
anything owing to a suppressive and deeply mixed profile (as is its
bias), and the NAM`s cool and wet bias depicting a very favorable
storm environment.

Below are the daily record highs - both for the date itself and
Easter (which falls on different calendar dates each year).

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
04-20   89(2002)       87(2002)       85(2023)       88(2002)
Easter  86(1946)       88(1946)       85(2011)

Tonight we will be mild and probably a few gusts mixing down at
times though a surface inversion will be setting up overnight.
Otherwise general synoptic setup won`t change much as the upper
trough hopping towards the Great Lakes maintains the southwesterly
flow regime over our neck of the woods.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 331 AM EDT Sun Apr 20 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 low.

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

Discussion:

We start the period with a closed upper low and surface low pressure
system moving east/northeast into the Great Lakes Region, with a
surface cold front to our west.  We will see height falls over our
area Monday in response to this system, and the weak front to our
west will move east into our area later Monday or Monday night
accompanied by some showers and thunderstorms. Timing of this
frontal boundary remains problematic as the models are not in good
agreement, but current indications are that it will move in Monday
afternoon or evening and will be near our southeastern border by
late Monday night.  The stronger jet dynamics look to remain to our
north and west with this system, and models continue to suggest
limited instability over most of our area with MLCAPES generally
around 500 J/kg or less in the afternoon, although values may be bit
higher south (but still likely less than 1000). The wind profiles
indicate deep-layer shear of 35 to 40 kts, driven mainly by speed.
Given all this, some stronger storms can`t be ruled out. However,
the overall setup and distance from upper-level support look to be a
hindrance to severe weather. A few strong to severe storms will
continue to be messaged with strong winds the primary threat.

The frontal boundary will stall out somewhere near our southeastern
border Tuesday.  Models have trended drier for Tuesday especially
northwestern portions of our area, but given the uncertainty of how
far the front progresses before stalling we will continue to have
showers and some thunderstorms in the forecast for Tuesday
especially south and east zones. Much of the remainder of the period
will feature generally southwesterly flow aloft over our area along
with the occasional short wave features that at this point are
poorly agreed upon by the models.  This will keep the possibility of
showers and storms in the forecast each day, although the forecast
most likely gives the impression of it being wetter than it will
actually be for much of the period.  It will also continue to be
quite warm. Near the end of the period in the Friday night/Saturday
time frame the models generally agree that a stronger short wave
aloft and a cold front will be moving in, with a better chance for
showers and storms.

&&

.AVIATION...
(12Z TAFS)
Issued at 710 AM EDT Sun Apr 20 2025

VFR and dry expected at terminals today, with a few puffy cu
clouds in the afternoon beneath a deck of high cirrus clouds.
Winds will remain less than 10 knots today except for a low chance
of some gusts to 15 to 20 knots at KCHA this afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             86  64  82  62 /   0   0  60  60
Knoxville McGhee Tyson Airport, TN  85  65  81  61 /  10   0  50  70
Oak Ridge, TN                       85  64  79  59 /  10   0  60  70
Tri Cities Airport, TN              84  59  81  57 /  10   0  30  70

&&

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

$$

SHORT TERM...Wellington
AVIATION...Wellington