690
FXUS64 KMRX 070800
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
300 AM EST Thu Nov 7 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Today and tonight)
Issued at 254 AM EST Thu Nov 7 2024

Key Messages:

1. Dense fog currently in the southern valley will dissipate this
morning. Another round of patchy fog is likely overnight tonight,
dense fog uncertain.

2. Light spotty rain showers again possible today, negligible
rainfall.

Discussion:

A frontal boundary draped to our north will gradually move closer
today and tonight, and will be the primary impetus for light rain
showers around the region today. Most CAMs depict what we`ve been
expecting for the last several days: weak, non-impactful light rain
showers. HREF mean CAPE depicts 250 to 500J of SBCAPE available for
shower development, and SPC contours the northern and western
edges of East Tennessee for thunder risk though wouldn`t be
surprised if we don`t hear any. Frontal boundary won`t make it
through the area today, which means our record highs and record
warm lows tonight will both be within a few degrees of record,
though right now the highs appear to be closer, depending on how
cloud cover and morning fog affect the diurnal temperature curve
today.

November 7th Record Highs

Tri-Cities   78 degrees (2022)
Knoxville    79 degrees (2023)
Chattanooga  83 degrees (2023)

Tonight partly cloudy skies and the warm lows will provide for
another night of patchy fog across the area, though I lack the
confidence to narrow down which areas will receive dense fog.
Perhaps the light rain showers today will provide enough moisture to
generate those areas of dense fog similar to where fog this morning
has formed relative to the prior day`s rain activity.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 254 AM EST Thu Nov 7 2024

Key Messages:

1.Above normal temperatures continue in the long term.

2. Chances for widespread rain look to be increasing for the
weekend, mainly Saturday night through Sunday night.

Discussion:

We start the period with a weak cold front to our south, surface
high pressure extending into our area from the north and northwest,
and upper ridging over our area. Friday will be dry with above
normal temperatures, but slightly cooler and also less humid than
preceding days.

Models are coming into better agreement in their handling of the
upper low that lifts out of the southwestern CONUS into the Great
Lakes Region over the weekend, and the weak cold front that pushes
through our area sometime in the Sunday night/early Monday time
frame. Saturday is now looking drier with the better moisture not
arriving until Saturday night. It looks like an area of rain will
begin to move in Saturday night and most areas will see rain Sunday
into Sunday night. Current model indications are that any convective
energy will be limited at best, but perhaps enough Sunday into
Sunday night for a few locations to hear some rumbles of thunder.
QPF values for this round of rain are currently generally in the
half inch to one inch range.

Drier air will be moving in behind the front Monday into Tuesday,
but no strong cooling so temperatures will remain above normal.
Models disagree on the timing of the next cold front with some
having it moving in Wednesday and others being slower. Given the
uncertainty that far out, have no argument with the low NBM PoPs for
showers Wednesday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1229 AM EST Thu Nov 7 2024

Dense fog in the southern valley will continue overnight. Patchy
fog for the northern area, but confidence is too low on how dense
or widespread the fog may be to affect KTYS or KTRI. Conditions
will likely improve after daybreak. Very spotty light showers
tomorrow during the daytime over the whole area, before dry
weather returns after 00z. Winds light through the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             81  64  78  56 /  20  10   0   0
Knoxville McGhee Tyson Airport, TN  80  62  75  51 /  20  10   0   0
Oak Ridge, TN                       79  61  76  50 /  20  10   0   0
Tri Cities Airport, TN              77  59  73  43 /  20  20   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Dense Fog Advisory until 9 AM EST /8 AM CST/ this morning for
     Anderson-Bledsoe-Bradley-Hamilton-Knox-Loudon-Marion-McMinn-
     Meigs-North Sevier-Northwest Blount-Northwest Monroe-Rhea-
     Roane-Sequatchie-West Polk.

VA...NONE.
&&

$$

SHORT TERM...Wellington
AVIATION...Wellington