399
FXUS63 KJKL 260315
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1115 PM EDT Fri Apr 25 2025

.KEY MESSAGES...

- Showers and and a few thunderstorms remain possible into the
  overnight hours.

- A cold front passing through from northwest to southeast late
  tonight and Saturday morning will bring somewhat cooler
  temperatures for the weekend, with warmer readings then making a
  comeback for the new work week.

- More showers and thunderstorms may affect the area starting around
  the middle of next week.

&&

.UPDATE...
Issued at 1110 PM EDT FRI APR 25 2025

A few areas of showers were moving across the southeastern portions
of the area as of 11 PM, with additional showers and a few
thunderstorms occurring in portions of central and western KY
near an approaching cold front. With the cold front and 500 mb
trough still upstream of the area, showers will remain possible
overnight and a thunderstorm will remain possible until the front
passes. Overall, grids were updated based on recent observations
as well as radar trends.

UPDATE Issued at 805 PM EDT FRI APR 25 2025

Showers and a times some thunderstorms have been moving generally
east and northeast across the area this evening in advance of a
shortwave trough and an approaching cold front. Hourly grids were
freshened up based on recent observation and radar trends and this
led to no substantial changes at this time.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 520 PM EDT FRI APR 25 2025

20Z sfc analysis shows a broad area of low pressure over the
northwest portion of Kentucky and Ohio Valley. Eastern Kentucky is
in the large warm sector from this, but also under plenty of
cirrus clouds. Much of the instability has been hard to develop or
worked out by the various showers and storms moving through
during the afternoon. However, we will need to watch the potential
for stronger storms organizing to the west in a clearer area and
where the winds are favorable for rotation allowing for stronger
updrafts. The main concern with these storms will be strong wind
gusts as the work east into our area. Otherwise, temperatures are
running in the upper 60s to low 70s. Meanwhile, amid winds from
the south at 5 to 10 mph - away from any storms, dewpoints have
come up to range from the upper 50s east and mid to upper 60s in
the west.

The models, and their individual ensemble suites, continue in
pretty good agreement aloft through the short term period. They
all depict a deepening shortwave trough crossing the Great Lakes
and northeastern Ohio Valley tonight and on Saturday. This
process is also pushing a weaker impulse west to east above the
area this evening as a dip in the mid level flow works through
northern Kentucky. This weaker feature peaks over the JKl CWA by
06Z and is then followed by rising 5h heights and northwest mid
level flow. This will become the pattern holding through the rest
of the weekend while drying occurs at lower levels. The continued
small model spread supported using the NBM as the starting point
with minimal adjustments needed through the period - mainly to
include some radiational cooling based terrain distinction in
temperatures Saturday night as well as near term CAMs inclusion
for PoPs and thunder chances.

Sensible weather features an active evening of showers and
thunderstorms before a cold front drops into the area later
tonight. Some instability and enough low level shear will keep
the concerns for strong storms in the forecast into the first part
of the evening. Most of these cells should be progressive enough
to limit the potential for training and hydro concerns, but they
are not zero and have been mentioned in the HWO. The instability
quickly fades towards midnight west to east leaving just an area
of showers to slowly progress through eastern Kentucky, preceding
a cold front, late tonight. CAA and upslope flow in the front`s
wake will keep showers in the forecast for early Saturday, but
clearing arrives most places by afternoon with sunshine helping to
yield near normal high temperatures south but on the cool side
northwest. The mostly clear skies (at least for the northern
2/3rds of the JKL CWA) will mean good radiational cooling later
Saturday night as the winds die down letting a decent ridge to
valley temperature split develop - along with valley fog - as the
most sheltered spots drop toward 40 degrees.

The changes to the NBM starting point consisted primarily of
adding terrain distinction to the temperatures for Saturday night.
As for PoPs - included some details from the CAMs consensus for
much of the area this evening and into the overnight.

.LONG TERM...(Sunday through Friday)
Issued at 602 PM EDT Fri Apr 25 2025

After a cool and dry Sunday, the long term forecast period trends
towards warmer and wetter conditions. A building midlevel ridge will
push a post-frontal, Canadian surface high pressure system to the
east at the start of the forecast period. The associated northerly
wind components will keep temperatures cooler through the end of the
weekend, with highs in the mid to upper 60s. Some thermometers may
reach 70 degrees, but guidance has begun to pick up on some high
level clouds streaming around the ridge and into the area on Sunday
afternoon/evening. This could limit the amount of radiational
heating/cooling that is realized on Sunday. As a result, overnight
ridge-valley temperature splits have been limited to the
northeastern portions of the forecast area. There, the coolest
valleys could drop down into the lower 40s. Southwestern portions of
the forecast area should see lows in the upper 40s/near 50.

By Monday, surface flow will have veered towards the south in
response to the departing high. The aforementioned midlevel ridge
will strengthen and shift east, with its axis stretching up from the
Tennessee Valley and into the Great Lakes. The combination of
southerly return flow and a shortwave disturbance riding the right
side of the ridge reintroduces slight shower chances on Monday. PoPs
will peak in accordance with the diurnal temperature curve, as there
will be no synoptic frontal forcing to spark widespread CI. Expect
highs in the upper 70s/near 80, with isolated afternoon showers
south of the Mountain parkway.

The ridging features will continue to shift east on Tuesday, with
the axis now stretching up the Appalachians and into Quebec. This
orientation will turn the flow aloft west-southwesterly as surface
flow veers further towards the southwest. Warm air advection
throughout the column will favor afternoon highs climbing well into
the 80s, priming the atmosphere for more widespread showers and
thunderstorms as a well-defined cold front approaches from the NW on
Tuesday evening/night. The best upper level dynamic support for this
system remains displaced to the northwest of our forecast area, but
it is plausible that upstream convection will congeal into a QLCS
immediately ahead of the front and then approach Eastern Kentucky
overnight. If this came to fruition, LREF joint probabilistic
ensemble guidance for CAPE/Shear/CIN suggests that the atmosphere
will progressively become less favorable the further south/east the
line gets into KY overnight. The Storm Prediction Center has
accordingly outlined far northwestern portions of our forecast area
in their Day 5 Severe Weather Outlook.

The upper level troughing support for this frontal boundary is
expected to eject into Maritime Canada by Wednesday afternoon, with
ridging remaining firmly in place over the SE CONUS. This will place
Kentucky in a regime of quasi-zonal flow aloft as a second system
begins to organize on the leeward side of the Southern Rocky
Mountains. A warm, moist airmass will remain in place on the south
side of the now-stalled boundary, allowing shower and thunderstorm
chances to persist into Wednesday and Thursday. Thursday`s storms
have a chance to be on the stronger side as that lee cyclone ejects
northeast towards the Midwest. At this temporal range, details
remain uncertain, but there is a signal in some of the long range
machine learning guidance for severe weather at the very end of the
period. We will also have to closely monitor the potential for
localized hydrological issues due to the successive days of
thunderstorm chances. In short, expect a warm and wet end to the
long term forecast period, MaxTs in the upper 70s/lower 80s, MinTs
in the lower 60s, and multiple rounds of showers and
thunderstorms.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 823 PM EDT FRI APR 25 2025

Numerous showers were crossing the area at issuance time and there
were also a couple of isolated thunderstorms and a mixture of
mainly MVFR and VFR conditions were reported. Reductions to MVFR
at least briefly are anticipated within any stronger showers in
advance of an upper level disturbance and cold front during the
first couple hours of the period. Thereafter, as the front nears
and crosses the area, prevailing MVFR should spread to the VA and
WV borders by 07Z with further reductions to IFR spreading from
northwest to southeast about 2 to 3 hours after MVFR develops.
Showers will gradually diminish from northwest to southeast
behind the front between 06Z and 15Z. Improvements to MVFR and
and/or VFR should occur from about 15Z to the end of the period.
Outside of showers and storms, winds will generally remain less
than 10 KT from the southwest through 04Z and then gradually
become west between about 04Z and 11Z. Then during the last 12
hours of the period, winds will become more northwest to
northerly as high pressure begins to build in.

&&

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

&&

$$

UPDATE...JP
SHORT TERM...GREIF
LONG TERM...MARCUS
AVIATION...JP