921
FXUS63 KJKL 101926
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
326 PM EDT Mon Jun 10 2024

.KEY MESSAGES...

- Slightly cooler than normal and pleasant weather will hold
  through mid-week.

- Hot weather arrives late this week, with highs in the upper 80s
  to lower 90s taking hold by Sunday.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 326 PM EDT MON JUN 10 2024

The afternoon surface analysis shows a cold front is in the
process of pushing across eastern Kentucky this afternoon. We are
seeing NW flow at JKL likely indicating the passage of the front.
This front will lead to some wind gusts of 15-20 mph at times this
afternoon under decent mixing from the front. The other issue has
been more cloud cover and this has limited some locations form
achieving the afternoon high particularly in somewhat higher
terrain areas given the cold air advection. Overall lowered
afternoon highs in some locations toward the 25 percentile.
Outside this the post frontal stratus noted upstream will be
somewhat a challenge tonight, as the models including the HREF are
struggling to handle the progression southward of this. Overall
seems like it has been behaving and staying just short of eastern
Kentucky. This will be particularly interesting as ensembles and
deterministic guidance show a shortwave pushing southward late
tonight. This will put overnight lows in question, with more
clouds it could limit the ridge/valley splits. However, right now
we will keep the mid to upper 40s in the valleys and upper 40s to
lower 50s elsewhere.

This frontal boundary will usher in drier and cooler airmass for
Tuesday, with PWAT values in the 0.5 to 0.6 range based on the
HREF. This is around 2 standard deviations below normal for June.
In the mid-levels, ensembles and deterministic guidance are in
good agreement that we will see shortwave ridging leading to
rising heights. There could be a few pancake cumulus at around 4
kft, but expect mostly sunny skies Tuesday, with highs in the low
to mid 70s. Afternoon highs like this are around 5-10 degrees
below normals for JKL and LOZ climate sites for this time of year.
The skies will clear for Tuesday night and could once again lead
to ridge/valley temperatures splits with lows in the upper 40s to
lower 50s in the valleys and low to mid 50s on the ridges.

.LONG TERM...(Tuesday night through Sunday)
Issued at 451 AM EDT MON JUN 10 2024

Seeing better than usual agreement in the pattern aloft among the
operational models through Dy6, Sat with some minor divergence in
the solutions thereafter. Ensembles are quite similar with the
overall pattern as well. We begin the extended in the middle of a
transition of a retreat of the core westerlies northward along the
Northern Tier. The pattern aloft then amplifies again with a mean
troughing developing over the west coast and ridging across the
eastern CONUS by the end of the forecast window. Amplified heights
across the Great Plains does help induce some troughing over the
Great Lakes by Friday as some short wave energy dives southeast
into the Upper Ohio Valley. Ridging then strengthens and shifts
eastward into the eastern CONUS through the remainder of the
period.

Sensible weather features generally dry, fair weather. The
aforementioned trough moving through the Great Lakes on Friday
will drop a surface cold front into the Ohio Valley. This surface
front just does appear to make it into eastern Kentucky before
stalling out due to the lack of support aloft. With better
dynamics further north, there is little in the way of the
opportunity of rain. There are some minor PoPs across northern
portions of the forecast area. Depending on what guidance one
prefers, the front either lifts back to the northeast and/or
dissipates. Strong ridging aloft then exerts its control for the
remainder of the forecast.

Main concern through the period will be heat towards the end of
the period. With strong ridging aloft and surface high pressure
building into the southeastern CONUS, temperatures will be quite
warm. Ensemble solutions do show a high probability (50-60%) of
H850 temps climbing to between 18-20 C. This will drive
temperatures up to around 90 by the end of the week and into the
weekend. With a gradual and eventual influx of moisture into the
area, heat indices will climb to near or around 100 degrees by the
end of the period. However, with the moisture will come an
increase in PoPs as well, but more likely just beyond the end of
the current forecast window.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 134 PM EDT MON JUN 10 2024

A weak cold front is diving southward across eastern Kentucky this
afternoon. This is leading to scattered to broken cumulus field
and even some stratocumulus in the wake of the front at around 3.5
to 5 kft. There is some MVFR upstream, but guidance doesn`t push
these lower ceilings into the area for the most part. Given this
will keep all the CIGs VFR through the period. The skies will
clear tonight and could see another round of valley fog, but TAF
sites should stay VFR. The winds will be out of the west-
northwest in most cases this afternoon at around 5-10 knots with
gusts in the 14-18 knot range. These will slack off through the
evening to around 5 knots or less.

&&

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

$$

SHORT TERM...DJ
LONG TERM...RAY
AVIATION...DJ