FXUS63 KJKL 231215 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
815 AM EDT Sun Aug 23 2026

.KEY MESSAGES...

- Noticeably cooler and less humid air will arrive behind a cold
  front to start the new week.

- Chances for a few showers and thunderstorms return around 
  midweek.

&&

.SHORT TERM...(Today through Monday)
Issued at 520 AM EDT SUN AUG 23 2026

Early this morning, an enlongated upper low was centered over
sections of the Great Lakes with an upper trough axis southeast
into the mid OH Valley and Central to Southern Appalachians to 
the Carolinas with an upper ridge centered in NM with ridging 
extending across portions of the western Conus into the Central 
Conus/Plains. Drier air has been gradually moving into the Lower 
OH Valley and eastern KY behind a cold front though the drier air 
has made a bit less progress into the more southern and 
southeastern locations as a ridge of sfc high pressure builds into
the Lower OH valley from the mid and upper MS Valley regions. 
Rather extensive fog mainly in the valleys has spread into some no
valley locations. Some observation sites such as KEKQ, KSME, and 
KI35 have recently reported dense fog and fog appears on the dense
side at some KY Mesonet station locations as well as on a few of 
the KYTC cameras. With that in mind, have opted to issue an SPS 
for fog over the next few hours for areas generally south and 
southeast of the I-64 corridor. 

Today and tonight, gradual 500 mb height rises are anticipated as
the upper low meanders to the eastern Great Lakes and sections of
the mid Atlantic states and axis of the upper trough remains east
of the Commonwealth. At the same time, the sfc ridge of high
pressure will build across the Commonwealth and into sections of
the mid OH Valley by late tonight. A dry airmass for this time of
year will be ushered into eastern KY with PW per the 00Z HREF
expected in the 5th to 20th percentile. This will set the stage
for not much in the way of cloud cover today other than diurnally
driven cumulus following the lifting and dissipation of the fog 
through the 9 AM to 10 AM EDT timeframe this morning. Mixing 
should result in dewpoints dropping a bit below NBM deterministic 
values. This airmass will also be cooler as well as drier and this
should support highs around 5 degrees below normal for the day on
Sunday. The pattern should again favor valley fog formation along
the rivers, larger creeks, and area lakes tonight. The normally 
colder locations may drop to as low as 52 or 53 tonight with the 
drier airmass in place with more in the way of solid mid 50s for 
valleys where fog forms and ridgetop locations on the order of the
upper 50s to near 60. On Monday, 500 mb heights should continue a
general upward trend as the axis of the upper trough moves 
further east of the Lower OH Valley and Appalachians and upper 
ridging centered in the NM vicinity builds in sections of the 
Central Conus/Plains and toward the MS Valley. One more shortwaves
will be moving around this ridging and near the mid MS Valley 
area by Monday evening. Highs for Monday should be similar to 
Sunday with northwest to west northwest flow aloft prevailing.

.LONG TERM...(Monday night through Saturday)
Issued at 450 AM EDT SUN AUG 23 2026

The long term period should begin with an upper low centered over
Quebec and an axis of an upper trough south into the mid Atlantic
states to the Carolinas to VA while an upper level ridge should 
be centered over NM and extend into portions of the western Conus
as well as the Central to Southern Plains/portions of the Central
Conus. Also at that point, another upper level low should be near
the Saskatchewan and Manitoba border with an associated trough 
south into the eastern MT and easter WY border area with the 
Dakotas. Further west, an upper trough is expected to extend from 
west of the coast of BC to west of the Pacific Northwest. At the 
surface, a frontal zone should extend from the eastern Carolinas 
across the Gulf coast states into the Southern Plains on Monday 
evening while a sfc ridge of high pressure should extend for the 
Appalachians to the western Great Lakes while a low pressure 
system should be near the Manitoba and Saskatchewan border with a
trailing cold front into the Dakotas with the frontal zone 
extending into the western Conus. 

From Monday night to Tuesday night, a weak shortwave moving around
the ridging over much of the Rockies and into parts of the Central
Conus should move through the OH Valley and Commonwealth but it
will be moisture starved with mainly just some passing high 
clouds. Some height rises at 500 mb are progged during the day on
Tuesday, before near neutral height tendencies or some subtle 500
mb height falls are forecast for Tuesday night as troughing 
remains from eastern Canada into the Northeast Conus/eastern 
seaboard and the upper ridge remains centered in southern NM 
thought it is progged to build north through sections of the 
Rockies. Meanwhile the upper low initially just north of ND should
trek gradually into Ontario and near the northern Great Lakes. 
This leaves northwest to west northwest flow aloft across the 
Commonwealth and Lower OH Valley into the central to southern 
Appalachians. During this time, a ridge of sfc high pressure will 
shift across the Lower to Mid MS Valley and Central Appalachians 
and become centered in the mid Atlantic states by late Tuesday 
night. At the same time, additional disturbances moving around the
ridging centered in NW should interact with the frontal/baroclinic
zone initially south of eastern KY with a sfc wave tracking to 
near the confluence of the OH and MS Rivers late Tuesday night 
while further east the boundary lifts into the TN Valley as a warm
front and approaches. This may lead to a bit of increase in 
moisture and some cloud cover at mid and high levels late Tuesday 
night. Sfc high pressure will remain the dominant feature with a 
drier airmass, with PW on the order of 20th to 30th percentile if 
not most of the time lower per LREF, in place will allow for lows 
in the mid 50s to near 60 on ridges and the development of valley 
fog along the rivers, larger creeks, and areas lakes both Monday 
night and Tuesday night. Daytime highs on Tuesday trend closer to
normal for late August. 

Wednesday to Thursday night, a shortwave trough from the mid MS
Valley to the Ozarks regions should move east into the Lower OH
Valley and parts of the TN Valley and SOutheast as an upper low
initially over Ontario and the northern Great Lakes weakens as it
moves further east and begins to interact and merge with an upper
low/trough centered over the Hudson Bay vicinity. This leaves an
upper trough axis from the Hudson and James Bay area south across
the Central Great Lakes to the OH and TN Valleys to Southeast by 
late Thursday night. During this period the upper ridge in the 
western/southwestern Conus becomes centered further west and 
southeast to the south of the Four Corners region with the axis of
the upper ridge extending into the Southern Plains with another 
axis north and northeast into MT and Alberta and Saskatchewan 
that shifts east across WY and eastern MT to Saskatchewan. At the
same time, an upper low moves into BC with the trailing trough 
moving into the Pacific northwest and sections of the interior 
northwest. Meanwhile as the initial shortwave trough moves across 
the area at midweek the sfc wave should track over or near 
eastern KY while the sfc low in the Great Lakes reaches the 
Northeast and sends an associated cold front across eastern KY 
Thursday. This will lead to isolated to scattered shower and 
thunderstorm potential over eastern KY that may tend to peak on 
Thursday near and ahead of a cold front. The consensus of guidance
is for a return of near normal temperatures.

Friday to Saturday, the upper trough axis is progged to shift east
with a broad trough in place from Ontario and Quebec into sections
of the eastern Conus. Guidance has a trend of rising 500 mb heights
and more of a zonal/westerly flow at that point with upper level 
ridges centered near Bermuda and the southwest Conus to end the 
period. This will lead to some initial small chances for showers 
and thunderstorms mainly on Friday afternoon before rising heights
likely suppresses convection on Saturday. Temperatures should
remain near normal for late August. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 810 AM EDT SUN AUG 23 2026

Fog lingered at issuance mainly for locations south of I-64 with 
all but KLOZ and KIOB among the TAF sites affected by MVFR to IFR 
if not locally lower reductions initially. This fog should lift 
and dissipate through 14Z, with VFR conditions generally 
prevailing through the end the period. Valley fog may again 
develop by the 04Z and 06Z timeframe, and KLOZ and KSME may be
affected per guidance with lower confidence for KSJS and KJKL with
no reductions for that period included at this point. Winds should
average less than 10KT as high pressure settles across the area.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...JP
LONG TERM...JP
AVIATION...JP