205
FXUS63 KJKL 250551 AAC
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
151 AM EDT Tue Jun 25 2024

.KEY MESSAGES...

- Heat and humidity return for Tuesday and Wednesday.

- Next best chance of rain will be Wednesday into Wednesday
  evening.

- Hotter weather is expected to make a comeback by Friday and
  Saturday, with afternoon highs in the low to mid 90s and heat
  index values around 100 degrees.

&&

.UPDATE...
Issued at 1120 PM EDT MON JUN 24 2024

No significant changes to the forecast with just the inclusion of
the latest obs and trends for the T/Td/Sky grids with this update.
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 MON JUN 24 2024

23Z shows a brief change in air mass thanks to weak high pressure
settling over eastern Kentucky today. This brought somewhat cooler
and drier conditions to the area along with fair weather cu that
is now diminishing with the loss of daytime heating. These should
be good conditions for a moderate or large ridge to valley
temperature split tonight along with areas of valley fog.
Currently, temperatures range from the mid 70s in some of the
sheltered low spots to the lower 80s on the hills and in more
open terrain. Meanwhile, amid light northerly winds, dewpoints
have fallen into the upper 50s to lower 60s. With the forecast on
track have mainly updated it to just add in the latest obs and
trends for the T/Td/Sky grids. These minor tweaks have been sent
to the NDFD and web servers.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 254 PM EDT MON JUN 24 2024

The surface high in place today will push east tonight and mid-level
ridging will build poleward some tonight. This will aid in paving
the way for clear skies and calm conditions to the area tonight.
Given this is expect reasonable ridge/valley splits of up to 10
degrees are expected tonight. There will also be mainly river
valley fog setting up later tonight into Tuesday morning. Tuesday,
the mid-level ridge will peak across the Ohio Valley. There will
be some high clouds from upstream system that the HREF is showing
and therefore will undercut the NBM operational forecast afternoon
highs slightly, which seemed overdone. Even so, we will see upper
80s to lower 90s by Tuesday afternoon. Right now, the NBM keeps
it dry for Tuesday and with ridging this seems reasonable.
However, some CAMs show a small chance (less than 15 percent) of
activity from overnight convection making it into parts of
Kentucky. This will have to be watched as this will be more a
mesoscale feature which are difficult for models to latch onto at
this point. Tuesday night, more clouds will push southward as the
ridge breaks down and trough pulls east. The guidance is showing
a fair amount of uncertainty on when and where we will see rain
on Tuesday night given again the more mesoscale nature of this
activity. For now, keeping close to the NBM, with areas generally
north of the Mountain Parkway seeing around a 15 to 30 percent
chance of rain and thunderstorms mainly in the early morning hours
Wednesday.

.LONG TERM...(Wednesday through Monday)
Issued at 235 PM EDT MON JUN 24 2024

A rather active long-term forecast period is expected as there`s
going to be a shift in overall synoptic pattern. The first of a
handful of disturbances is expected to bring a cold front into the
region Wednesday afternoon through Wednesday evening. A couple small
perturbations revolving around a parent trough will favor surface
low development over the Great Lakes with a cold front extending
southwest through the Commonwealth. The SPC has given eastern
Kentucky a marginal risk of severe weather with this boundary as
FROPA is expected mid-day to maximize the potential for instability
building. Forecast soundings have decent severe weather indices in
place across the area. Decently steep low and mid level lapse rates
are in place, instability around 2,500 J/kg in the afternoon is
favorable, PW`s around 2.00" which if materialized could bring some
heavy rainfall but overall the most lacking parameter is the lack of
bulk shear across the region. Low shear values could limit the
overall strength of the storms but not really minimize the potential
for thunderstorms. Also, the potential for increased cloud cover
could limit the ability to increase instability which alone could
limit the coverage of the thunderstorms. Thunderstorms will taper
off from northwest to southeast through the overnight Wednesday but
an H850 shortwave is forecast to develop with a surface feature
riding along the departing cold front. The surface low will keep
shower and thunderstorm chances across the far eastern third of the
CWA through the day Thursday before the whole trough ejects to the
northeast.

Behind the exiting trough, height rises are forecast for
Friday morning. At the surface, high pressure will establish itself
and persist through the day Friday and half of Saturday before
another upper-level wave dives southeast out of western Canada and
approaches the Great Lakes dragging a cold front through the
Commonwealth from Saturday night through Sunday with another
perturbation providing a renewing shot of showers and thunderstorms
Sunday into Monday. High pressure will build back into the region
for the end of the period. Overall, the entire period will be
highlighted by multiple rounds of showers and thunderstorms with
high temperatures remaining in the mid-80s to low-90s and overnight
lows in the upper-60s to mid-70s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 150 AM EDT TUE JUN 25 2024

High pressure at the surface will keep mainly VFR through the
period with one exception. Patchy valley fog has developed in
some of the river valleys and reductions there to MVFR or IFR are
possible prior to 13Z. However, the TAF sites are not expected to
be affected. Winds will be light and variable to calm through 13Z,
with light and variable winds thereafter.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...VORST
AVIATION...JP