485
FXUS64 KMRX 060548
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
148 AM EDT Thu Jun 6 2024

...New AVIATION...

.UPDATE...
Issued at 937 PM EDT Wed Jun 5 2024

Latest radar shows an MCS off to our southwest moving northeast,
and while the latest hi-res CAMS suggest this will weaken rapidly
this weakening trend seems to be overdone. Right now it looks like
there is low but significant chance that this will hold together
long enough for a few stronger storms to make it into our
southwest corner with strong winds the main threat, but a
weakening trend is still expected. Will make some significant
adjustments to PoPs/Wx to better fit latest radar trends and model
guidance with this update, with much lower PoPs to start the
period.

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 302 PM EDT Wed Jun 5 2024

Key Message:

Gusty winds with locally heavy downpours and isolated flooding are
possible with the strongest storms. The flooding concern will linger
into the overnight hours more so than the threat for a few stronger
storms.

Discussion:

Currently showers are moving throughout area and those in northeast
TN and southwest VA are moving into more unstable air... Enough that
we`re starting to see some lightning strikes within the strongest
cells. Expect these storms to continue to move northeastward through
the rest of the afternoon and evening. Still looks as though the
biggest hazard with the strongest storms is gusty winds, small hail,
and heavy downpours. Storms are currently moving northeast at a
steady clip, so it would likely take multiple storms training over
one area to cause flooding of urban and low lying areas.

Heading into the sunset and beyond hours we should see a lull in
storm activity ahead of the actual frontal passage coming in from
the west/northwest. Front looks to begin moving through overnight
into tomorrow with additional storms along this boundary. Due to the
timing of the frontal passage strong storms are not anticipated, but
heavy downpours could once again aggravate swollen creeks or streams.

&&

.LONG TERM...
(Thursday night through next Wednesday)
Issued at 302 PM EDT Wed Jun 5 2024

Key Message:

1) Drier and cooler Friday through Saturday.

2) Showers and thunderstorms return Sunday into Monday as a
system moves through the region.

3) Slightly below normal temps in place through the long term.

Discussion:

By Thursday night, the cold front has moved through the region and
northwesterly flow is in place aloft bringing a drier, cooler
pattern. On Friday, a trough remains over the East Coast with high
pressure over the Southeast at the surface. By Saturday, the trough
flattens out over the Northeast and Great Lakes. Northwest flow
continues aloft and at the surface high pressure weakens over our
region. Friday and Saturday will be dry and cooler than normal with
highs in the mid 70s to lower 80s in the Tennessee Valley. Normal
highs for Saturday are 82, 84 and 86 for Tri Cities, Knoxville and
Chattanooga respectively.

On Sunday, a shortwave moves through the pattern with possibly a
cold front at the surface. The best chance for showers and storms
appears to be in the daytime. Sunday night into Monday, there is
less model agreement in rain chances. GFS has a drier solution and
the Euro has the wet pattern continuing through Monday as a
shortwave moves through the pattern Sunday night/Monday. Keeping
fairly low POPs during that timeframe given the uncertainty. Severe
potential seems low with dew points struggling to rebound but a few
strong storms cannot be ruled out. Below normal temps will continue

&&

.AVIATION...
(06Z TAFS)
Issued at 141 AM EDT Thu Jun 6 2024

Expect isolated to weakly scattered showers during the overnight,
thus, have opted for vcsh at all sites. Very low chances of any
thunder during this time frame. Ensemble guidance suggest around a
40-60% chance of MVFR cigs building into the region mid to late
morning. Have only included this in tempo form given low-med
confidence. Additional scattered showers and few storms will swing
through the area this afternoon, although, highest confidence in
vicinity activity exists at TYS and TRI. Southwest winds will
generally remain between 5-15kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             87  65  83  60 /  30   0   0   0
Knoxville McGhee Tyson Airport, TN  84  61  80  57 /  60  10   0   0
Oak Ridge, TN                       85  60  80  56 /  60  10   0   0
Tri Cities Airport, TN              80  58  76  54 /  70  10   0   0

&&

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

$$

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