279
FXUS63 KJKL 132019
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
419 PM EDT Sun Jul 13 2025

.KEY MESSAGES...

- Warm/hot temperatures and high dew points will persist for the
  next week, resulting in sultry conditions.

- There will be a daily potential for showers/thunderstorms over
  the next week, especially in the afternoon/evening hours.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 418 PM EDT SUN JUL 13 2025

A modest trough in the prevailing upper level westerlies is
crossing eastward over the Great Lakes late today, with a weaker
extension further southwest to TX/OK. This is giving us weak
southwest flow aloft on the perimeter of subtropical ridging. A
seasonally fairly moist atmosphere is present with a tall thin
CAPE profile, and showers/thunderstorms have increased in
coverage (especially over our southern counties) with diurnal
destabilization. Instability and shear combos don`t look favorable
for severe wx, and it would probably take strong outflow
interaction to have concerns. However, the storms are slow moving
and with the CAPE profile they are beginning to show localized
hydro concerns. Activity should show a decline this evening with
slow loss of instability. However, the weakening upper trough will
continue to approach tonight as it becomes increasingly strung
out, and additional convection can`t be ruled out. With the last
vestiges of the trough still over the area on Monday, and diurnal
heating once again, another increase in showers/thunderstorms
should occur. The CAPE profile looks similar, without a big
concern for severe wx. Flow aloft is forecast to increase a bit
with cells moving a little faster, and with that, hydro concerns
are a bit less. Activity will once again decline on Monday night,
probably to a greater extent due to the demise of the upper
trough.

.LONG TERM...(Tuesday through Sunday)
Issued at 314 PM EDT Sun Jul 13 2025

When the long forecast period opens on Tuesday morning, an upper
level ridge will have nudged its way into Southern Kentucky. Thus,
Tuesday looks to be the driest day in the long term forecast period,
albeit the afternoon hours are still marked by scattered
shower/storm chances. After any leftover clouds from Monday`s
activity and the AM valley fog burn off, efficient diurnal warming
processes should yield notably warmer highs near 90. This exceeds
the convective temperature thresholds visible in modeled BUFKIT
soundings, but a lack of dynamic support aloft and only marginal
amounts of CAPE should limit the impacts of Tuesday`s
showers/storms. That activity should begin to subside after sunset
and as overnight low temperatures cool down towards 70 degrees.

For the rest of the long term forecast period, the guidance suite
collectively resolves a stagnant weather pattern over the eastern
half of the country. A broad anticyclone is forecast to remain
parked over the Southeastern states, whereas zonal flow will move
through the Upper Midwest and into the Great Lakes. The Ohio River
Valley will be situated between the two, and our sensible weather
will accordingly be driven by characteristics of both. Southwesterly
flow in the lower levels of the atmosphere will persistently advect
a warm, moist airmass into the Commonwealth, keeping temperatures
and humidity high. This will lead to above-normal PWATs and
increasingly oppressive heat indices on Wednesday and Thursday.
Expect afternoon highs in the low 90s on both days and peak heat
indices in the upper 90s in the deepest valleys and urban corridors.
These warm/humid conditions will combine with some shortwave
impulses moving through the broader zonal flow to enhance
precipitation chances across the area on Wednesday and Thursday.
Thunderstorms will be possible, but they are likely to remain pulse-like
in nature. Weak winds aloft and dry air in the column will mitigate
deep-layer shear and thus the potential for highly-organized
convection. This is particularly true for southern KY, which will be
closer to the center of the southeastern ridging.

Thus, the greatest sensible weather impacts over the area next week
will likely come from the cumulative nature of the heat and the
repetitive nature of the precipitation chances. Rain chances will
peak every day in the afternoon/evening hours, and the heaviest
showers could provide some localized relief from the hot apparent
temperatures. However, overnight lows near 70 degrees will provide
limited nocturnal relief. The NWS HeatRisk tool has been picking up
on the potential for heat-related health impacts across Eastern
Kentucky in the Wednesday-Thursday time frame. Likewise, WPC has
outlined the forecast area in Marginal (Level 1/4) Excessive
Rainfall Outlook on both Wednesday and Thursday. The potential for
localized flash flooding will be highest in areas that see multiple
rounds of heavy rain multiple days in a row next week, as soils in
those places will progressively be able to absorb less moisture.

Guidance suggests that the SE ridge may flatten late next week and
allow a weak frontal boundary to slide into the forecast area. This
could yield slightly cooler afternoon highs in the 80s, but a lack
of deep upper level support means that said front is likely to stall
out. This will keep diurnally-peaking rain chances in the forecast
for next weekend, and we will closely monitor the potential for any
potential excessive rainfall-related impacts as the mesoscale
details of the forecast become clearer by mid-week.

In short, expect an active summertime weather pattern to persist
across Eastern Kentucky this week. Confidence is high that Eastern
Kentucky will experience seasonably warm/humid conditions and daily
diurnal peaks in shower/storm chances throughout the next week. Only
minor adjustments were made to the NBM-populated long term forecast
grids, as it is capturing the general pattern well. Confidence in
the magnitude of overnight ridge-valley temperature splits is low
due to the potential for lingering clouds from diurnal convection.
Likewise, nocturnal fog may form in locations with wet grounds
beyond the typical river valleys. With that being said, grid edits
were limited to minor reductions in valley low temperatures, minor
increases in ridgetop low temperatures, and the addition of valley
fog in the weather grids.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 418 PM EDT SUN JUL 13 2025

Scattered showers/thunderstorms were ongoing at TAF issuance,
mainly in our southern counties, and were bringing localized sub-
VFR conditions. Otherwise, conditions were VFR. This scenario will
persist into the evening, but an overall decrease in activity is
expected. Late tonight, fog development is forecast, especially in
valley locations which received rain. This will bring localized
IFR or worse conditions. Fog will dissipate on Monday morning.
Another increase in showers/thunderstorms should occur on Monday
after diurnal heating/destabilization kicks in.

&&

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

&&

$$

SHORT TERM...HAL
LONG TERM...MARCUS
AVIATION...HAL