044
FXUS63 KJKL 201340
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
940 AM EDT Thu Jun 20 2024

.KEY MESSAGES...

- Hot and mainly dry weather will occur through the weekend.
  Afternoon heat indices will peak near 100 at some locations.

- The upper level high/ridge bringing our heat wave will weaken
  during the weekend and eventually allow a cold front to at least
  approach the area, with the PoPs peaking in the 40 to 60 percent
  range Sunday night ahead of the front.

- Uncertainty still exists concerning the progress of the cold
  front next week and whether or not a substantially drier air
  mass will arrive. For this package, Monday night through Tuesday
  afternoon were left dry, but with precipitation and
  thunderstorm chances returning late Tuesday night and continuing
  through Wednesday night.

&&

.UPDATE...
Issued at 940 AM EDT THU JUN 20 2024

No major changes made to the forecast grids except loading the
latest hourly obs and updating morning text and radio products to
remove any mention of fog. Grids have been saved and sent.

UPDATE Issued at 721 AM EDT THU JUN 20 2024

Fog, more widespread than at any time in the last week, will
slowly burn off over the next 1 to 2 hours, yielding sunny skies.
Updated forecast removes the wording for early this morning, but
still keeps fog in for a couple of more hours. Otherwise, there
are no changes to the forecast. Hourly observations were blended
into the forecast to make for a seamless transition.

&&

.SHORT TERM...(Today through Friday)
Issued at 329 AM EDT THU JUN 20 2024

Statistical guidance late last evening trended more aggressive
with fog potential for the early morning hours, and this has
materialized as fog has been more widespread and more dense than
in previous early morning periods recently. Have included mention
of this in the HWO product, but will withhold any other products
at this time. The fog will burn off by 9 AM this morning.

The models are in good agreement regarding the large scale flow
pattern aloft in the short term. A strong ridge of high pressure
remains in place across most of the eastern third of the CONUS to
begin the period, and will be the dominant weather feature for
eastern Kentucky through Friday. A couple of models still try to
push a weak disturbance aloft through the region, sparking isolated
showers and storms over portions of the area later today, especially
during the afternoon. However, confidence in this scenario unfolding
is quite low at this time, due to the strength of the ridge that
will be in place and the amount of dry air that is expected to be in
place through out the low levels of the atmosphere. For those
reasons, we kept precip chances well below 15% today still. An
increase in cloud cover is now included today to account for the
potential passage of the weak disturbance aloft over the surface
ridge during the afternoon. That all being said, it still appears
that today will be dry.

With overall less cloud cover today, expect high temperatures to
rebound back into the 90s for many locations, through with more
cloud cover forecasted than initially expected in the northwest
part of the CWA, highs may trend nearer to 90 degrees with perhaps
a few upper 80s.

For tonight, expect mostly clear to partly cloudy skies with the
typical fog forming in the river valleys. Lows in some of the
typically cooler sheltered valleys have remained elevated by a few
degrees from expectation the last couple of nights, especially in
the Upper Kentucky River Basin, so this will need to be watched in
case lows need to be raised back a couple of degrees. Nevertheless,
the current forecast calls for lows in the mid 60s to lower 70s
tonight.

PoPs rise somewhat Friday afternoon but still remain below the 15
percent threshold for mention in the forecasts and grids. This is
due to a disturbance moving southeast from the Midwest toward the
Carolinas, which is likely to also bring some increase in cloud
cover. This will do little to keep highs from once again reaching
the 90s, with heat indices once again approaching 100 degrees.

.LONG TERM...(Friday night through Wednesday)
Issued at 402 AM EDT THU JUN 20 2024

The models remain in overall good agreement regarding the long
wave pattern through the period, although detail differences
concerning smaller scale features grow with time by next week.
Ridging will be in the process of dampening and drifting southwest
Friday night, with the center reaching the lower Mississippi
Valley by early Saturday. Meanwhile, progressive short wave
energy will be moving through the northern states and into the
Great Lakes within the westerlies. Late this weekend and
especially into next week, the ridge will restrengthen and take up
residence near the Four Corners region, while deeper troughing is
reinforced east of the Mississippi River, as additional bouts of
traversing short wave energy move through the region.

Hot temperatures will continue to be the main story through the
period, with highs averaging in the low to mid 90s. Saturday
continues to look like the overall warmest day, with heat indices
topping a 100 degrees for some locations. While a stray shower or
thunderstorm can not be completely ruled out for Saturday,
coverage would be fairly isolated in nature due to weaker forcing
in place. As such, will keep PoPs just below 20%. A cold front
will begin to approach from the northwest Sunday, with model
guidance somewhat slower compared to yesterday. PoPs continue to
peak in the 40-60% range late Sunday night into early Monday
morning, with rain chances lingering southeast on Monday, as
moisture only slowly retreats behind the departing boundary.
Tuesday looks to be mainly dry, as short wave ridging generally
takes hold. Overall, the ensemble guidance has trended down on
rain probabilities over the last few model runs for this period;
however, depending on the evolution of the short wave energy, this
could change. Another cold front will approach from the northwest
Tuesday night into Wednesday, with rain chances increasing to
30-40%. Highs will retreat to the upper 80s to around 90 on
Monday, before warming back to the lower to mid 90s for Tuesday
and Wednesday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 725 AM EDT THU JUN 20 2024

Fog at KSYM, KSME, and KLOZ should burn off by 13z this morning.
VFR conditions are then expected until late in the TAF period
overnight when fog will likely return. While somewhat confident in
fog occurrence at TAF sites where mentioned, the duration and
severity are less certain. Winds will average less than 5 kts, and
generally from the north to west direction.

&&

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

$$

UPDATE...VORST
SHORT TERM...CMC
LONG TERM...GEOGERIAN
AVIATION...CMC