139
FXUS64 KMRX 122320
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
720 PM EDT Mon Aug 12 2024

...New AVIATION...

.SHORT TERM...
(This evening through Tuesday)
Issued at 229 PM EDT Mon Aug 12 2024

Key Messages:

1. Mostly areas stay dry stay dry through the short term.

2. Slight chance POP northeast TN and southwest VA tomorrow
morning. Slight Chance POP east TN mountains tomorrow afternoon.

Our northwest flow pattern remains in place due to a broad trough
to our northeast and ridging to our west. Expect dry conditions
overnight with below normal temperatures around 5 degrees below
normal. A weak and moister starved shortwave will move through the
Ohio River Valley tomorrow morning. As a result, NBM gives a
slight chance POP and increased cloud cover for northeast TN and
southwest VA. Most other areas expected to be dry through the day.
However, slight chance POPs in place across the east TN mountains
during afternoon peak heating. High temps will be near normal.

&&

.LONG TERM...
(Tuesday night through next Monday)
Issued at 229 PM EDT Mon Aug 12 2024

Key Messages:

1. Near normal temperatures continue.

2. Mostly dry conditions through mid-week before increasing chances
of showers and storms late week into the weekend.

Discussion:

Not a whole lot to speak on for the first few days of the extended
period. Surface high pressure and associated subsidence will keep
the area mostly dry, though an occasional diurnal pop-up shower
cannot be ruled out in the higher elevations. Temperatures will
remain seasonal and are likely to do so through the majority of the
long term.

An upper level shortwave will influence the deepening of surface low
pressure in the upper mid-west by the late week. As this surface low
progresses across the western Great Lakes and into Michigan we can
expect enhanced frontogenetical forcing locally. This will lead to
heightened chances of showers and thunderstorms by Friday and into
Saturday. Model derived soundings suggest periods with Bulk
Effective Shear approaching 25-30kts and a low-end southwesterly LLJ
near 30kts. We will need to keep an eye on potential strong/severe
chances over the coming days but aforementioned soundings also
suggest a limiting factor may be available energy, with CAPE values
generally 1500 J/kg or lower Friday. Even less so by Saturday due to
a worked over environment & potential lingering cloud cover.

For Sunday and into early next week, troughing looks to remain
anchored over the Ohio Valley and into the mid-south. Persistent
deep northwesterly flow will allow for lingering PoP chances during
this time, however, PWAT falling to near 1 inch and a thermodynamic
profile trending more stable all suggest that any signals for
notable impacts will be well diminished.

&&

.AVIATION...
(00Z TAFS)
Issued at 718 PM EDT Mon Aug 12 2024

VFR conditions expected for the next 24 hours. Light winds and
mostly clear skies will continue, with a chance of a brief shower
this evening across southwest Virginia being the only weather of
note.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             90  67  91  69 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  87  63  88  64 /   0   0   0   0
Oak Ridge, TN                       86  63  88  65 /   0   0   0   0
Tri Cities Airport, TN              84  58  84  61 /   0  20  10   0

&&

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

$$

SHORT TERM...
LONG TERM....KRS
AVIATION...