021
FXUS63 KJKL 041446
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1046 AM EDT Fri Jul 4 2025

.KEY MESSAGES...

- Today will be hot and a little more humid. High temperatures
  will reach the upper 80s to low 90s.

- The weekend brings the hottest air. Expect widespread high
  temperatures of 90 to 95 degrees, feeling oppressive at times, with
  a low chance of isolated afternoon showers or thunderstorms,
  mainly on Sunday.

- A more active weather pattern begins Monday with the threat of
  daily thunderstorms, some of which could bring locally heavy
  rain. Though still oppressive on Monday, daily high
  temperatures gradually ease into the mid to upper 80s by mid-
  week.

&&

.UPDATE...
Issued at 1045 AM EDT FRI JUL 4 2025

Just a quick refresh based on the latest observations and updating
morning text and radio products to remove mention of fog. Grids
have been saved and sent.

UPDATE Issued at 715 AM EDT FRI JUL 4 2025

No major changes to the grids except updating the next few hours
based on current surface trends. Also, updated morning text and
radio products to reflect those changes. Grids have been saved and
sent.

UPDATE Issued at 1145 PM EDT THU JUL 3 2025

No significant changes were made to the forecast with mainly just
the inclusion of the latest obs and trends for the T/Td/Sky grids.
These minor adjustments have been sent to the NDFD and web
servers along with a freshening of the zones and SAFs.

UPDATE Issued at 745 PM EDT THU JUL 3 2025

23Z sfc analysis shows high pressure in control of the weather
over eastern Kentucky. This is keeping the winds light and skies
mostly clear, though a few stray sprinkles are noted over western
parts of the area that will fade out with sunset. Currently,
temperatures are running in the upper 70s to lower 80s. Meanwhile,
dewpoints are generally in the low to mid 60s. Have updated the
forecast mainly to add in the latest obs and trends for the
T/Td/Sky grids as well as some sprinkles in the west. These minor
adjustments have been sent to the NDFD and web servers along with
a freshening of the zones and SAFs.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 237 PM EDT THU JUL 3 2025

Surface high pressure continues to exert its dominance across much
of the CONUS. This persistent pattern has maintained, and will
continue to maintain, warm and dry conditions over the forecast area.

Today, surface high pressure will ensure warm and mostly dry
weather. However, a slight increase in moisture introduces very
isolated chances of showers and thunderstorms this afternoon, which
are expected to dissipate around sunset. Any developing shower or
storm will produce heavy rainfall, though severe weather is not
anticipated. Highs today are forecast to climb into the mid to upper
80s, and with the aforementioned moisture increase, heat indices
will feel two to three degrees warmer than the actual air
temperature. Tonight will mirror recent evenings, with lows in the
low to mid-60s accompanied by widespread river valley fog.

Independence Day will feature slightly warmer temperatures and
elevated heat indices due to a further increase in atmospheric
moisture. This moisture advection is a result of an upper-level
trough tracking from the Great Lakes towards the Northeast, which
will diminish the influence of drier northwesterly flow. Showers and
thunderstorms are again possible Friday afternoon, though confidence
in their exact coverage and location remains low. Any activity that
does develop is expected to dissipate towards sunset. Friday night
will be similar to Thursday night, with overnight lows in the mid-
60s and river valley fog.

In summary, surface high pressure keeps mostly dry weather with high
temperatures climbing into the mid to upper 80s. Overnight lows will
generally remain in the mid 60s, with widespread valley fog
expected.

.LONG TERM...(Saturday through Thursday)
Issued at 300 PM EDT THU JUL 3 2025

Hot, humid and generally rain-free conditions over the weekend
will transition to an unsettled weather pattern heading into the
new work week. The analysis based on the 03/12z model suite,
beginning Saturday morning, shows a 500H ridge axis stretching
from northwest Mexico to the Ohio Valley. A broad associated
surface high is centered near/over the Delaware River Valley.
Multiple Pacific shortwaves are riding over the ridge, the first
of which will be over the Upper Midwest, interacting with a much
deeper upper level trough over the Hudson Bay to northwest
Greenland. This supports a potent low over the Hudson Bay with a
cold front extending to a weak surface low pressure wave over
Minnesota. From there, the front extends westward to over Montana
where a second Pacific shortwave is crossing the northern Rockies.

The ridge aloft reaches its peak strength over the Commonwealth
on Saturday before partially breaking down on Sunday as the first
shortwave trough settles southeast toward the Ohio Valley. The
weekend days will feature the hottest air mass (850 mb temps of
20-21 Celsius) aloft while, at the same time, humidity levels rise
due to the southerly return flow on the back side of the surface
high. Enough height falls and moisture increase are anticipated by
Sunday afternoon for isolated afternoon pop-up convection. Right
now the greatest opportunity for rainfall on Sunday appears to be
near/over the higher mountains adjacent to the Virginia and
Tennessee borders. Rain chances become more widespread on
Monday/Monday night as the first shortwave guides its associated
cold front into eastern Kentucky. As the features better forcing
skirts to our north on Tuesday, guidance is muddled as to how far
south the boundary will actually reach before stalling. A weak
wave of low pressure, forced by the second 500H shortwave trough,
then rides along the stalled boundary into the Ohio Valley mid-
week. The waffling frontal boundary and low pressure wave will
keep diurnally-modulated convection in the forecast through the
remainder of the long-term forecast period. As 850 mb temperatures
ease back into the 17-18 Celsius range by mid-week, PWATS are
conversely favored to rise above 1.5 inches for most of the time
from Monday afternoon onward. Of particular note, the modeled
combination of a very moist atmosphere, a deep warm cloud layer,
skinny CAPE profiles, and generally weak steering flow will be
favorable for locally heavy rainfall.

In more sensible terms, look for a quintessential Fourth of July
weekend with a lot of heat and rising humidity levels -- perfect
weather for the first dog days of summer. Saturday is favored to
have the hottest air temperatures of the two weekend days with
highs ranging from 90 to 95 degrees, but moderate humidity levels
will still keep it from feeling too oppressive. Saturday night
will still cool off decently into the mid 60s to near 70. Sundays
air temperatures are forecast to peak about a degree cooler than
Saturday but higher humidity levels will still make it feel like
the middle 90s. Mostly sunny skies are likely on both days with a
little more cloud cover on Sunday, when there will also be a low-
end chance of a popup shower or thunderstorm. A daily scattered to
numerous thunderstorm threat returns on Monday and continues
through the remainder of the period. Some of the showers and
thunderstorms could produce heavy rain. Under the more humid
regime, daily high temperatures continue subsiding back into the
mid to upper 80s by mid-week. Heat indices will follow a similar
trend, after peaking in the 95 to 100 degree range for most
locations on Monday afternoon.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 627 AM EDT FRI JUL 4 2025

River valley fog developed earlier this morning, reducing
visibilities at some of the terminals to IFR conditions. Once the
fog dissipates by ~13Z, any affected terminals will return to
VFR. Light and variable winds will continue through the period.

&&

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

&&

$$

UPDATE...VORST
SHORT TERM...VORST
LONG TERM...GEERTSON
AVIATION...WFO SGF