517
FXUS63 KJKL 150700
AFDJKL

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

.KEY MESSAGES...

- 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 Wednesday.

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

&&

.SHORT TERM...(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 through Friday)
Issued at 400 PM EDT FRI JUN 14 2024

Models are in general agreement for the overall pattern that will
affect our area during the long term period. Upper level high
pressure will start out centered in the vicinity of the southern
Appalachians on Sunday. It is expected to shift north to near NYC at
mid week, and then back south to the vicinity of VA on Friday.
The ridge is now expected to keep convection capped much of the
time for our area. However, one exception is Monday, when the GFS
and ECMWF both allow for a bit of mainly diurnal activity in the
afternoon and evening as an area of somewhat higher moisture
rotates around the western side of the high center. In terms of
model differences, the main issue is in the strength of the
high/ridge, with the ECMWF being stronger than the GFS, especially
later in the week. The weaker GFS allows for deep convection to
boil up on Thursday and Friday, whereas the ECMWF is dry. This
results in hotter temps in the ECMWF. Will allow for a model blend
to smooth out these differences for now, with only a slight
chance of precip to be mentioned.

&&

.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...HAL
AVIATION...CMC