775
FXUS63 KJKL 090314
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1114 PM EDT Fri Aug 8 2025

.KEY MESSAGES...

-While most of the area will remain dry and warm today, a low
 chance for a few isolated afternoon showers or thunderstorms
 exists, primarily southwest of KY-15.

-The weekend looks even better, with dry conditions and warm
 temperatures expected for both Saturday and Sunday, making it
 great for outdoor plans.

-A significant pattern change arrives for the new work week,
 bringing a more humid pattern with daily chances for scattered
 afternoon and evening thunderstorms starting Monday.

&&

.UPDATE...
Issued at 1114 PM EDT FRI AUG 8 2025

Showers dissipated during the evening and the forecast is on
track. Only inconsequential changes were made to blend late
evening obs into the forecast.

UPDATE Issued at 808 PM EDT FRI AUG 8 2025

A few very isolated showers were lingering in our southern
counties early this evening, and a 20% POP has been extended in
the very near term for that area.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 257 PM EDT FRI AUG 8 2025

Surface high pressure dominates much of the CONUS, leading to dry
weather across the region. While scattered cumulus clouds have
formed due to daytime heating the significant shower activity is
confined mostly to Tennessee. However, in the Bluegrass region, a
few showers have attempted to develop but have been short-lived,
likely producing only virga or light sprinkles.

For the remainder of the day, temperatures will climb into the upper
80s to low 90s. The chance for very isolated showers and storms will
persist, primarily affecting the southern counties. The development
of widespread convection will be suppressed by a combination of
rising upper-level heights and limited atmospheric moisture. Any
storms that do manage to form will dissipate with the diurnal cycle.
Overnight, temperatures are forecast to drop into the mid to upper
60s. River valley fog is possible, but its coverage will be limited
due to the general lack of moisture.

Saturday will bring a continuation of the same weather pattern.
Temperatures will again rise into the upper 80s and low 90s. The
high-pressure dome is expected to strengthen, increasing subsidence
which will further suppress convection and result in even more
limited chances for precipitation. Saturday night will be similar to
Friday night, with valley fog being even more restricted due to the
persistently marginal moisture levels.

The general trend for the period is a return to more seasonal to
slightly above seasonal temperatures, with very isolated chances for
showers and thunderstorms. The dominant high pressure will continue
to suppress widespread rainfall, keeping conditions generally dry.

.LONG TERM...(Sunday through Friday)
Issued at 502 PM EDT Fri Aug 8 2025

After a sunny Sunday dominated by atmospheric ridging, a pattern
shift will favor more active weather in Eastern Kentucky for much of
the next work week. The forecast guidance suite generally agrees
upon the timing/positioning of the synoptic-scale features
responsible for this pattern shift, and this leads to generally high
levels of confidence in the baseline NBM forecast data used to
populate the long term grids. Therefore, only minor, climatology-
based grid edits were needed with this forecast package issuance.

When the period opens on Sunday morning, models collectively resolve
a broad 500mb ridge stretching up from the Gulf Coast towards Lake
Ontario. At the same time, upper level troughing and a related
surface cold front will extend from South-Central Canada down into
the Upper Midwest. Eastern Kentucky will begin the period positioned
just to the right of the ridge`s axis; this favors a surface weather
map reflection of nearby high pressure and weak anticyclonic flow.
The resultant sensible weather should be mostly sunny, with highs in
the upper 80s to lower 90s. Subsidence and height rises should
prevent any diurnally-driven cumulus clouds from developing into
meaningful showers/storms on Sunday. Overnight, expect ridge-valley
temperature splits. Valley locations are poised to cool down into
the mid 60s, and river valley fog has been added to the forecast
grids accordingly. The warmer ridgetops should remain clearer and in
the 68-70 range. Given all of the above, Sunday`s forecast looks
seasonably pleasant for any planned outdoor activities and events.

On Monday, the aforementioned ridge axis is expected to shift
further to the east and place the region on the western side of the
related surface high pressure system. In response to this shift,
atmospheric flow is forecast to gradually veer towards the southwest
early next week and foster moisture return. As this occurs, the
Midwestern cold front is expected to lose its upper atmospheric
support and stall out to the north of the Ohio River. With no clear
frontal passage, highs are forecast to remain in the upper 80s/lower
90s on Monday and Tuesday. These warm temperatures, combined with
increasing amounts of atmospheric moisture, will usher diurnally-
driven scattered showers and thunderstorms back into the forecast on
Monday and Tuesday afternoons.

Ridging is expected to build back over the Southeastern and South-
central CONUS by mid-week, placing the Greater Ohio River Valley in
a regime of quasi-zonal flow. A series of shortwave disturbances are
likely to ride the ridge towards the forecast area in the Wednesday-
Friday time frame, and PoPs remain in the forecast through the end
of the period as a result of this activity. The latest
deterministic runs of both the GFS and the Euro show a better-
defined shortwave trough moving through the Commonwealth on
Wednesday, and this mirrors the timing of the highest PoP grids in
the NBM. If the greater convective coverage on Wednesday comes to
fruition, forecast highs could under-perform and be relegated to the
low/mid-80s due to the related increase in cloud cover. In a similar
manner, if these clouds linger overnight into Thursday, they could
also mitigate the climatologically-expected ridge-valley temperature
splits and limit overnight valley fog formation. As Wednesday`s
forecast comes within the temporal range of higher-resolution
modeling, mesoscale trends in the above variables will need to be
monitored closely. Trends in mesoscale convective parameters will
also need to be monitored. The synoptic signal for organized, strong-
to-severe convection is unremarkable next week, with LREF joint
probabilities for favorable CAPE/CIN/Shear parameters generally less
than 20%. However, increasing amounts of SBCAPE and increasing PWAT
values (mean Grand Ensemble values of > 1.75 inches on Tuesday and
Wednesday) mean that any storm that does develop next week could
produce locally heavy rainfall and brief bursts of gusty winds.

In short, expect another week of typical diurnal summertime
convection in Eastern Kentucky and typical summertime MaxTs in the
mid/upper 80s. The increase in humidity alongside these highs would
typically point towards heat concerns, but the daily rain chances
should provide localized relief and reduce the likelihood/spatial
coverage of heat indices above 100. Thus, the main idea of this
particular long term forecast package is the shift towards a more
active pattern.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 808 PM EDT FRI AUG 8 2025

Valley fog is forecast for late tonight into early Saturday, with
localized IFR or worse conditions. However, TAF locations are
likely to evade. Otherwise, VFR conditions are expected through
the period.

&&

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

&&

$$

UPDATE...HAL
SHORT TERM...VORST
LONG TERM...MARCUS
AVIATION...HAL