539
FXUS63 KJKL 190919
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
519 AM EDT Sat Sep 19 2026

.KEY MESSAGES...

- Well-above normal temperatures persist this weekend with near
  record values both days over the Cumberland River Basin.

- The heat, humidity, and a nearby frontal boundary could foster
  isolated to scattered thunderstorms across the area at various
  times over the next several days.

- Rain chances increase early next week as the persistent upper
  level ridging breaks down.

&&

.SHORT TERM...(Today through Sunday)
Issued at 519 AM EDT SAT SEP 19 2026

The unseasonably warm and muggy pattern of late continues across
eastern Kentucky, with temperatures settling back into the upper
60s to lower 70s this morning--more typical of mid-summer than
mid-late September. A mixture of fog and low stratus is found in
most places following yesterday`s hit-and-miss shower and
thunderstorm activity. The latest surface analysis shows a poorly
defined frontal boundary draped across the region from the
Carolinas through much of Tennessee and then northwest to a weak
surface low over Iowa. Looking aloft, an ~594 dam upper-level
ridge is centered over northeast Texas while eastern Kentucky
remains on its northeastern periphery.

This will place eastern Kentucky under deep-layer northwesterly to
westerly flow as the aforementioned frontal boundary wavers back to
the north over the next couple of days. Multiple weak
disturbances moving through the flow could spark a few showers and
thunderstorms, most likely during the afternoon or evening,
coincident with peak heating and destabilization. Many HREF/REF
members hint at a more substantial MCS developing over Indiana
and portions of Ohio this afternoon, dropping southeast this
evening and weakening, potentially brushing portions of
northeastern Kentucky. Some of the guidance also suggests isolated
activity bubbling up farther south. The best instability is
favored to be upstream of our area while the better shear remains
farther north, but any storms that do develop or move in from the
northwest will have access to a moderate 1000 to 2000 J/kg of
SBCAPE and DCAPE values near 1000 J/kg, bringing the potential to
produce strong to isolated damaging wind gusts. Therefore, SPC has
maintained a Marginal Risk (1/5) of severe weather for today. The
story appears similar for tomorrow, including a Marginal Risk
SWODY2, but there is little model agreement on timing for any
particular round of convection as upper-level disturbances remain
weak.

In sensible weather terms, fog and low stratus will gradually lift
this morning. This will leave behind mostly to partly sunny skies for
this afternoon, and similar skies will follow on Sunday. Both
weekend days will also remain quite hot for this time of year, with
temperatures ranging from the mid 80s in the northeastern hills to
the lower 90s over the Cumberland River Basin. There will also be a
threat of showers and thunderstorms, isolated to scattered in
coverage during the afternoon and evening, though a rogue shower
or thunderstorm cannot be ruled out at another time. Meanwhile,
Saturday night will remain warm and muggy, with lows mainly in the
mid 60s to around 70F along with the typical favored river valley
fog.

.LONG TERM...(Sunday night through Friday)
Issued at 342 AM EDT SAT SEP 19 2026

A rather chaotic upper level setup is anticipated across the CONUS
to start the long term period. The main belt of prevailing
westerlies aloft will be well to our north, largely in Canada. South
of that, a number of features semi-disconnected from the main flow
will be over the CONUS, but with largely zonal flow over the Ohio
Valley and little flow to the south. A surface frontal boundary
should be stalled over or near KY along the southern edge of the
flow aloft. This boundary could serve as a broad focus for
convective development Sunday night into Monday.

The most significant feature aloft for our local area at the start
of the period will be a trough (and possibly weak low) over the
northern plains. This feature traces back to a current position over
ID. As it drifts east, models are in relatively good agreement
through Wednesday for it to form a larger closed low near the Great
Lakes. The resulting trough over the eastern CONUS will support a
transition to cooler weather, but the details of potential fropa for
the local area are a little messy, as the cooler air is expected to
make better progress down the eastern side of the Appalachians. This
potentially pinches the warmer air mass along the western side here.
We should see an increased POP with the transition in air masses
around mid week, but the details are murky as to how/when a full
transition eventually takes place. Model solutions also begin to
show more variation with the evolution of the upper low at the end
of the week, particularly in the way it shifts east and with ridging
trying to build east toward the Great Lakes. This lowers confidence
in the forecast at the end of the period.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 142 AM EDT SAT SEP 19 2026

At the 06Z TAF issuance, the last few showers were dissipating
over the Lake Cumberland region. Otherwise, a mix of fog and low
stratus were already developing across the area and are likely to
lead to MVFR to VLIFR ceilings/visibilities overnight. The worst
conditions generally expected at terminals south of I-64 and east
of I-75. Improving conditions back to VFR are expected from 13 to
16Z Saturday. Some thunderstorms will be possible again during the
afternoon out of the northwest. PROB30s are present at all sites
except SME to account for this potential. Conditions could drop
into MVFR or worse should a thunderstorm occur. Winds should remain
light and variable through the period, except locally strong and
erratic near thunderstorms.

&&

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

&&

$$

SHORT TERM...GEERTSON
LONG TERM...HAL
AVIATION...GEERTSON/GINNICK