899
FXUS63 KJKL 062036
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
436 PM EDT Sat Jun 6 2026

.KEY MESSAGES...

- Daily chances for showers and thunderstorms return Sunday
  afternoon, then persist through most of next work week.

- The greatest rain chances are on Monday, Tuesday, and Wednesday,
  and the potential for multiple rounds of locally heavy rainfall
  poses a risk for isolated flooding in this time frame.

- Hot and humid conditions escalate through the week, with
  widespread apparent temperatures in the mid to upper 90s likely
  by Thursday and Friday.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 429 PM EDT Sat Jun 6 2026

Eastern Kentucky remains under the influence of the dominant SE
CONUS ridge this afternoon, with efficient diurnal processes
accordingly observed across the region. A field of diurnal cumulus-
type clouds is visible in this afternoon`s satellite imagery, as are
some mid- to high-level clouds. Occasional, faint radar returns
suggest that this activity may try to produce some sprinkles, but no
meaningful precipitation is expected through tonight. Diurnal mixing
has led to widespread 20+ degree dewpoint depressions, with
afternoon highs in the 80s. Model soundings resolve a subsidence
inversion in the midlevels of the atmosphere above the commonwealth,
which will limit the depth of these clouds. These conditions also
point towards efficient radiational cooling after sunset, when the
cumulus field is forecast to subside.

Expect overnight ridge-valley temperature splits tonight. Sheltered
and shaded valleys should decouple and then cool into the upper
50s/lower 60s tonight, whereas the warmer ridges will hover in the
mid to upper 60s. Near water sources like lakes, creeks, rivers, and
streams, radiational fog should develop. Confidence in fog formation
is highest in the Cumberland River basin, which will be closer to
the core of the parent ridging features. Further to the north, the
aforementioned mid/high level clouds could limit the areal coverage
of this fog. These northern locations are closer to the base of a
trough axis drawn through the eastern Great Lakes and the Upper Ohio
River Valley, but that trough`s surface boundary reflection will
stall out before making it into our forecast area. Thus, no major
sensible weather impacts are expected to stem from that system
tonight.

The front gets abandoned by its upper level support tomorrow, and
then omega-shaped shortwave ridging builds into the region in its
wake. Expect another day of dominant diurnally-driven processes,
with fog burning off after sunrise and temperatures steadily rising
into the 80s as the day progresses. The atmosphere does look
relatively more moist tomorrow than it was does, which should
correspond with relatively greater amounts of cloud cover. This
cloud cover could cause temperatures to under-perform current
expectations, but convective temperatures should still be reached to
the north of the Mountain Parkway. These northern portions of the
forecast area will also be closer to that stalled boundary, and
isolated to scattered showers and thunderstorms may develop during
peak diurnal heating. While 500-1000 J/kg of CAPE will be in place,
weak winds aloft will relegate shear to sub-30 knot values and
prevent storms from organizing to strong/severe limits. However, the
same winds that determine shear parameters also play a role in
determining storm propagation speed. So, any storms that develop
tomorrow will be slow-moving.

On Sunday night, the narrow ridge axis propagates east and allows
for deeper southerly to southwesterly flow to set up. Expect a
further increase in cloud coverage and thus an interruption in the
typical diurnal cooling curve. Significant ridge-valley temperature
splits and radiational valley fog are not in the forecast for Sunday
night. Rather, temperatures may actually increase headed into Monday
morning as the stalled frontal boundary lifts back north in the form
of a warm front. The related increase in isentropic lift will spread
rain chances from SW->NE across the area after midnight on Monday
morning. This sets the stage for a more active weather pattern early
next week, and we will have to closely monitor what areas (if any)
experience meaningful rainfall ahead of that pattern`s onset. If
localized, slow-moving downpours materialize on Sunday afternoon or
night, they could prime soils for isolated hydrological issues
during the more widespread convective activity discussed below in
the long term forecast discussion.

.LONG TERM...(Monday through Saturday)
Issued at 415 PM EDT SAT JUN 6 2026

The period is expected to begin with an upper level ridge centered
in the Great Lakes extending into the Carolinas, a shortwave trough
axis from the upper MS Valley to the mid MS Valley region, an upper
level ridge extending from the Southern to Central Plains and a
trough over the western Conus. At the surface, a frontal zone is
expected to extend from NC to WV to the Central Plains. At that
point, sfc high pressure should be in place off the Southeast US
Coast. Moisture will have increased to end the short term period
ahead of the slow moving shortwave nearing the OH Valley with PW per
the 00Z LREF mean progged in the 1.4 to 1.8 inch range or 80th to
97th percentile.

Monday to Tuesday night, the axis of upper level ridging is progged
to shift to the coast of the Carolinas to the mid Atlantic States to
Northeast to Quebec. At the same time, the slow moving shortwave
should move slowly east across the western and Central Great Lakes
and Lower OH Valley and near the Middle OH Valley, traversing
eastern KY during this time. PW should peak Tuesday evening with 00Z
LREF mean 1.6 eastern Pike County to 1.9 inches west. MUCAPE also
per the 00Z LREF is progged to peak between 500 and 1000 J/kg on
Monday and 700 to 1300 J/kg on Tuesday. Rounds of showers and some
thunderstorms are anticipated with thunderstorms mainly both
afternoons and evenings. Shear and storm motions will be weak
generally 10KT or less both days and this combined with the potential
for some locations to pick up multiple rounds of convection could
result in locally heavy rainfall and instances of high water or
flooding. With the increased moisture in the column and anticipated
increase in cloud cover and convection diurnal ranges will be more
limited than what has been observed recently.

Wednesday to Thursday night, the upper trough axis should gradually
shift to the east of the eastern KY and the Appalachians with at
least a period of brief height rises/shortwave ridging building into
the Commonwealth for a bit during this timeframe. Also during this
period, the upper level trough that will have began the period in
the western Conus will have migrated into the Plains/Central Conus.
Although moisture in the column will decrease somewhat, with PW
dropping back to the 90th to 95th percentile or the 1.5 to 1.7 inch
range, sfc dewpoints are progged in the upper 60s to lower 70s range
as moisture becomes more focused in the lower levels/boundary layer.
Chances for convection during these days should be highest on
Wednesday with the wave gradually shifting east. The timing of
height rises will determine the extent or coverage of any convection
from late Wednesday evening through Thursday. Some of the guidance
highs for Thursday would be too warm unless ridging suppresses
convection. The current Thursday highs are more in alignment with
ridging dominating. Meanwhile, the lower NBM deterministic and MOS
guidance values are more reflective of a scenario with a bit
greater coverage of convection.

Friday to Saturday, guidance generally has the upper trough
gradually working form the Central Conus into the Great Lakes to
Lower OH Valley. There is run to run variability with heights
across eastern KY and timing of this trough east to end the period
with the recent GFS operational runs more moist than recent ECMWF
runs. Convection will remain possible, especially each afternoon and
evening. Both high and low temperatures should remain mild to end
the week with limited diurnal ranges continuing.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 200 PM EDT SAT JUN 6 2026

Efficient diurnal processes are forecast given the ongoing weather
pattern, and this corresponds with the development of a cu field
across the terminals this afternoon. Scattered spatial coverage
of that cu field is observed across the southern two-thirds of
the forecast area. Further to the north, increased mid/upper level
clouds relegated that development to "few" coverage. Cu should
subside towards sunset, as will sporadic afternoon wind gusts
between 15 and 20 knots. Additional mid- to high-level clouds
linger overnight, but all ceilings will be above VFR thresholds.
River valley fog development is expected overnight, but given the
antecedent dryness and the lack of mentionable PoPs today, it is
not currently forecast to affect the TAF sites. Fog potential
looks greatest in the Cumberland River basin, so vsby reductions
cannot be entirely ruled out at southern terminals like KSME and
KLOZ. Recent probabilistic guidance has backed off the LAMP data`s
idea that these terminals will experience categorical impacts, so
fog potential was not explicitly mentioned in the 18z TAFs.
Observational trends will need to be monitored overnight though. An
increase in moisture tomorrow morning will lead to greater cloud
cover towards the end of the period, but mentionable rain chances
hold off until after 18z tomorrow afternoon. As such, VFR
conditions are expected to prevail at all TAF sites for the
current issuance period.

&&

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

&&

$$

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