-- Discussion containing changed information from previous version are highlighted. --
254
FXUS63 KJKL 150728
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
328 AM EDT Sat Jun 15 2024

.KEY MESSAGES...

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- Hot and somewhat humid weather arrives on Sunday and persists
  into the upcoming week. Afternoon heat indices may peak around
  100 at some locations Sunday through Friday.

- There is a slight chance of afternoon and evening thunderstorms
  Sunday, Monday, and Friday.
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&&

.SHORT TERM...
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(Today through Sunday)
Issued at 300 AM EDT SAT JUN 15 2024

The entirety of the short term period through early evening Sunday
will be punctuated by rising mid-level heights indicative of
strengthening high pressure across the area. The center of the
strengthening high will initially be to the west and southwest of
eastern Kentucky through this afternoon, but then shift to the
southeast of the area by Sunday evening.

Very dry mid-level air will work into the region today and remain in
place into Sunday, which will limit any potential for significant
cloud cover and precipitation. With a very dry air mass and
strengthening high pressure, one last night of significant ridge-
valley splits is expected tonight into Sunday morning with lows
around 60 degrees on ridges, but with upper 40s to mid-50s in the
more sheltered valleys.

A question mark for Sunday despite the dry air mass present is that
a few models, especially the GFS, have started trending towards
afternoon and/or early evening convection developing toward the
Tennessee border. Soundings indicate enough moisture for cumulus
development as a subtle upper disturbance moves north-northeast
across the area, but it is hard to see soundings so dry produce deep
convection. The GFS is by far the most aggressive with showers and
storms developing, with support from the MPAS mesoscale models. A
few CAMS have a few very isolated spotty showers or storms as well.

Regardless of convective development Sunday, the bigger story will
be the increasing heat, with highs jumping about 10 degrees from
Saturday to Sunday to peak in the lower to mid 90s in the afternoon.

.LONG TERM...(Sunday night through Friday)
Issued at 328 AM EDT SAT JUN 15 2024

The period will start off Sunday night with a large upper level
ridge spread across the state and points to our south and east.
Meanwhile, surface high pressure will also be pushing eastward, to
just east of the state, with return southerly flow in place across
the Commonwealth. Models are showing a surge of warm gulf moisture
into the Mississippi Valley on the backside of this high pressure
system during the day Monday, thanks to the strong southerly flow.
With afternoon mixing, warming temps, and increased moisture, models
are showing an expansion of pops by the afternoon, including
throughout Kentucky. These showers/thunderstorms really seem to be
only diurnally driven, and will quickly cease again by Monday
evening, and shouldn`t have much forcing. Did want to note that
these chance pops via the NBM are an increase from just isolated
during the previous runs.

After this point, heights will begin to build again across the
Commonwealth, with upper level ridging and surface high pressure
expected to remain in place through much of the week. This should
push much of the convection activity farther west and north, and
hopefully keep the JKL CWA dry. That being said, there is some model
disagreement, especially as you get towards the end of the week. The
GFS tries to bring pops southward across the state Thursday
afternoon through Friday afternoon. The ECMWF heights are actually
less across the region compared to the GFS during this time, but
keeps us dry. Given the uncertainties, kept with the NBM which went
dry for Thursday with this last run, and introduced very low end
isolated showers/thunderstorms for Friday afternoon, increasing on
Saturday afternoon. Expect the pops for the end of the week to
continue to evolve over the coming days.

The one thing that we can all agree on is the heat. With such a
strong ridge overhead, coupled with the surface high pressure just
to our east, the stage will be set for strong southerly WAA with
humidity. Even if we do see showers on Monday or later in the week,
they will provide little relief. Highs are still forecast in the low
to mid 90s throughout the week and into the weekend, with no frontal
passage expected to bring a change in the airmass. In addition to
this, the humidity will be a player given the advection of Gulf air
into the region. This will make it feel even warmer, with heat
indices expected to reach the upper 90s to around the 100 degree
mark in many locations.
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&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 126 AM EDT SAT JUN 15 2024

VFR conditions will generally prevail through the TAF period. Of
immediate concern in the next couple of hours is an outflow
boundary moving south across the forecast area, poised to cross
KJKL around 06z and then KLOZ and KSME toward 08z. This feature
will generate a few isolated showers that will most likely miss
the TAF sites, but will also bring a brief period of north to
north-northeasterly winds gusting up to 15 kts. Of note, a few
models bring a brief MVFR stratus deck that develops over the
area to KJKL, KLOZ, and KSME between 08z and around 13z. Will keep
any mention of this out of the TAFs given the low confidence.
Otherwise, the remainder of the TAF period will be quiet with only
passing high clouds and very light winds generally out of the
northeast.

&&

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

$$

SHORT TERM...CMC
LONG TERM...JMW
AVIATION...CMC