Tomahawk, Kentucky Weather Forecast Discussion

904
FXUS63 KJKL 020900
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
500 AM EDT Thu Oct 2 2025
.KEY MESSAGES...
- Dry and generally above normal temperatures persist into early
  next week.
- Into the weekend, valley fog is likely to develop each night.
- Chances for rain may return by Tuesday and/or Wednesday.
&&
.SHORT TERM...(Today through Friday)
Issued at 440 AM EDT THU OCT 2 2025
08Z sfc analysis shows eastern Kentucky under the influence of
dry high pressure to the northeast while lower pressure is found
to the southwest. The high is keeping the winds light and skies
mostly clear this night - though some high and thin clouds are
drifting over the area at the moment. Even with those clouds,
these conditions favored decent radiational cooling for the night
and resulted in a small to moderate ridge/valley temperature
divide throughout eastern Kentucky - while also allowing for areas
of dense fog formation in the river valleys. Specifically,
temperatures vary from the low to mid 50s in some of the low,
sheltered spots to around 60 on many thermal belt, hilltop
locations. Meanwhile, dewpoints are running in the low to mid 50s,
most places.
The models, and their individual ensemble suites, continue to be
in excellent agreement aloft through the short term portion of the
forecast. They all depict 5h ridging holding squarely above
eastern Kentucky through the rest of the work week. This will keep
mid level winds light and any energy far away from the area. In
addition, the ridging will suppress any convection through Friday
evening. The still very small model spread during the short term
portion of the forecast continues to support using the NBM as the
starting point of the grids with minimal adjustments needed -
mainly just to include terrain based enhancements for temperatures
at night.
Sensible weather features another couple of pleasantly warm and
dry days with temperatures reaching the low to mid 80s for highs
today and the low 80s on Friday, thanks to plenty of sunshine and
the dry air mass. Expect mostly clear conditions tonight with
valley fog again developing - becoming locally dense. High
pressure holding over the area from the east will continue this
extended summer-like warmth into the weekend.
The changes to the NBM starting point were primarily focused on
adjusting temperatures tonight for terrain based details along
with tweaking the afternoon dewpoints and RH a tad lower today and
Friday - capturing the mix down of drier air from aloft.
.LONG TERM...(Friday night through Wednesday)
Issued at 500 AM EDT THU OCT 2 2025
The main changes to the extended forecast this morning were to
enhance the terrain based differences of a ridge to valley split
for temperatures each night through the upcoming weekend. The
PoPs still are looking quite limited during the rest of the work
week and into the weekend.
The previous long term discussion follows:
The periods is expected to begin with an upper level ridge
extending from the OH Valley and Appalachians to off the coast of
VA and NC, while further west, another upper level ridge should
extend from Mexico in the Southern to Central Plains. Weak upper
level troughing should initially extend from the Atlantic across
the Bahamas and FL to the Gulf Coast and eastern Gulf. Further
west, an upper level trough is expected to extend across much of
the western Conus. At the surface, a ridge of high pressure should
extend from the Atlantic to the mid Atlantic states to the
Appalachians and TN Valley to Arklatex as the period begins.
Friday to Saturday night, upper level ridging is expected to
generally remain in place with the axis of this fridge from the
Atlantic to the VA and NC coast to the middle OH Valley and
Central Appalachians with another upper level ridge extending from
Mexico into the Southern Plains. Further west, the upper level
trough should remain over the western Conus, with a shortwave
trough progressing across the Rockies and into the Northern to
Central Plains. Over the Gulf to Gulf coast, upper level troughing
may evolve into a weak upper low near the lower MS Valley/MS delta
vicinity that moves into the western to northwest Gulf coast by
late Saturday night. The ridge of sfc high pressure meanwhile
should remain centered off the mid Atlantic coast with riding
extending into the OH Valley and eastern KY. At the same time, a
frontal zone will should move into the Northern to Central Plains
in advance of the shortwave trough working across parts of the
northern to central Plains. Across eastern KY, this pattern will
favor continued dry weather with mild temperatures about 5 to 8
degrees above normal for highs along with mostly sunny to sunny
skies for Friday and Saturday and most clear to clear nights.
Valley fog formation will also be favored each night along area
rivers, larger creeks, and area lakes. Some of this could become
dense in some locations. The fog should dissipate within 2 to 3
hours past sunrise each morning.
Sunday to Monday night, models begin to diverge a bit by the end
of the weekend with a bit more northern and northwestern upper
level low position early Sunday in the GFS with a continued trend
of a bit more aggressive moisture return north into parts of the
TN Valley and Appalachians. This trend carries over through Sunday
with much more substantial moisture return by Sunday afternoon
and evening across the TN Valley and Southern Appalachians and
encroaching on eastern KY in the GFS as compared to the past two
ECMWF that remained more consistent. Both models maintain the
upper level ridge centered near the eastern seaboard and bring a
shortwave across the Northern Plains and into the Upper MS Valley
and approach the western Great Lakes by Sunday evening. Sfc high
pressure will remain anchored off the mid Atlantic coast through
Sunday and Monday with ridging west into the OH Valley to end the
weekend. The shortwave trough that should be nearing the western
Great Lakes should progress into Ontario and Quebec through
Sunday night and Monday while the upper level ridge centered near
or all the eastern seaboard moves further from eastern KY. The GFS
continues to have more substantial moisture return into the
Appalachians than ECMWF with ECMWF runs more consistent from run
to run while the 12Z GFS was more aggressive than the prior run.
This moisture return will occur in advance of the next shortwave
trough progged to eject east across the Rockies and into the
Northern and Central Plains from troughing over the western Conus.
That shortwave should approach the Great Lakes through Monday
night and guidance is in general agreement that by Monday night
500 mb height falls should occur across the Commonwealth with the
GFS having this starting earlier and has deeper moisture across
eastern KY through Monday night. As the 500 mb heights begin to
fall, a frontal zone should also begin to approach the
Commonwealth from the northwest by the Monday to Monday night
timeframe.
For the weekend, rain free weather should continue with
temperatures remaining above normal. NBM pops were more in
alignment with the more consistent and typically better verifying
ECMWF and no changes were made. These did bring small chances to
near the TN border into the Lake Cumberland vicinity on Monday
afternoon followed by slight chances areawide later Monday night
as moisture increases, 500 mb height falls are progged, and the
frontal zone approaches. Somewhat better chances for measureable
rain hold off until a bit later in the week.
Tuesday and Wednesday, an upper level trough should advance east
from the Central Conus and across the Great Lakes, Lower and
Middle OH Valley, and into the Northeast to Southern Appalachians
and Southeast into Midweek. A sfc cold front should also move
across eastern near the end of the period as well. With moisture
expected to return into eastern KY, isolated to scattered showers
are anticipated with chances peaking Tuesday afternoon during
peak heating and again Wednesday near and in advance of the front.
A few rumbles of thunder could accompany convection to end the
period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 150 AM EDT THU OCT 2 2025
VFR conditions will prevail through the period at TAF sites, with
exception of KSME where fog is expected to develop after ~8Z.
Away from the primary terminals, locally dense fog will form in
the more sheltered river valleys, potentially impacting non-TAF
airfields (e.g. KBYL). The fog gives way to fair skies area-wide
after sunrise. In general, winds will be light and variable at
around 5 kts or less through the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...GREIF
LONG TERM...JP/GREIF
AVIATION...GEERTSON/GREIF

NWS JKL Office Area Forecast Discussion