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372
FXUS63 KJKL 111715
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
115 PM EDT Tue Jun 11 2024

.KEY MESSAGES...

- Slightly cooler than normal to near normal temperatures,
  comfortable humidity, and pleasant weather will hold through
  mid-week.


- Hot weather arrives late this week, with highs in low to mid 90s
  with heat indices approaching 100 degrees beginning Sunday and
  persisting into Monday.

&&

.UPDATE...
-- Changed Discussion --
Issued at 115 PM EDT TUE JUN 11 2024

Forecast remains on track for the most part. Early afternoon
update required only some tweaks to hourly temps and sky cover.
Updates did not impact the zones, thus no update there. Enjoy the
weather!

UPDATE Issued at 1034 AM EDT TUE JUN 11 2024

Forecast is pretty much on track. Brought hourly grids in line
with current surface observations, resulting in only minor changes
to the forecast. Increased sky cover across our eastern zones
just a bit through the mid-day time frame after the development
of a more substantial Cu field than anticipated. Also updated the
zone package to remove morning references. No other changes at
this time. With high pressure over the region and a light north-
northeast wind, ample sunshine...even across the east by later
this afternoon, should be a fantastic day to be outside.

UPDATE Issued at 725 AM EDT TUE JUN 11 2024

No substantial changes to the forecast with just the inclusion of
the latest obs and trends for the T/Td/Sky grids with this update.
These minor adjustments have been sent to the NDFD and web
servers.
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&&

.SHORT TERM...(Today through Wednesday)
Issued at 425 AM EDT TUE JUN 11 2024

07Z sfc analysis shows high pressure in place over the region
providing for a cooler and drier air mass over eastern Kentucky.
However, it has been slow to clear all the low clouds out of the
JKL CWA with some still holding on in the southeast. This has
likely curbed the temperature dropoff for those areas (as well as
hindered fog formation). Currently, temperatures range from the
low 50s in the deeper sheltered valleys to around 60 on the ridges
and for places under the clouds. Meanwhile, amid light winds,
dewpoints have fallen into the upper 40s and lower 50s. As the
last of the clouds continue to dissipate there is still a
potential for some river valley fog for much of the area through
dawn.

The models, and their individual ensemble suites, are in excellent
agreement aloft through the short term portion of the forecast.
They all depict the Northeast trough pulling out of the area
allowing 5h heights to rise over Kentucky through mid-week. The
bulk of any energy at mid levels, associated with the trough,
also pulls away from the state today. Slackening northwest flow at
mid levels will then continue above the area tonight through
Wednesday. One last weak impulse does brush by to the north and
east of the JKL CWA early Wednesday with maybe just a brief
increase in clouds but otherwise rather ineffectual. The model
spread is very small so that the NBM was used as the starting
point for the short term grids with little deviation necessary
aside from the incorporation of standard terrain distinctions for
temperatures early this morning and again tonight.

Sensible weather features another terrific and comfortable day
with only a small amount of cloud cover and afternoon temperatures
just on the low side of normal. Then tonight, under mostly clear
skies, we will have another cool one where many of the valleys
will reach the upper 40s by dawn Wednesday, along with a touch of
river valley fog around. Wednesday will be pleasant, too, but
temperatures will be on their way up - reaching normal to just
above for afternoon highs, this despite some extra clouds in the
south, while humidity levels remain comfortable.

The main changes to the NBM starting point consisted of adjusting
the temperatures in order to better represent terrain details in
a radiational cooling pattern this morning and tonight. PoPs were
kept near zero through the period.

.LONG TERM...(Wednesday night through Monday)
Issued at 346 AM EDT TUE JUN 11 2024

Weak upper-level northwesterly flow will be in place to start the
forecast period. At the surface, a dome a high pressure will exist
and will keep the forecast area hot and dry. Through the day
Thursday, an upper-level perturbation will move into the northern
Plains and through the Great Lakes. At the surface, a cold front is
forecast to extend southwest toward the Commonwealth and will slowly
track into the region. The front will provide enough lift to fire
off a few thunderstorms but mainly north of the CWA. However, can`t
rule out a stray thunderstorm along and east of the Mountain
Parkway. Surface high pressure will build back into the region post-
frontal with temperatures climbing into the 90s and heat indices
approaching 100 degrees for the end of the weekend into early next
week.

Models begin to diverge for the start of next week as the heat
begins to break as a potential system moves into the region. The
ECMWF is dry going into next week with the GFS being the more
aggressive of the two models. For the forecast package, opted with
the NBM solution that keeps slight chances of showers and
thunderstorms through the end of the period.

&&

.AVIATION...
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(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 115 PM EDT TUE JUN 11 2024

CU field that developed across our far east and provided some
temporary MVFR CIGS is showing signs of eroding as drier air
continues to mix down through the boundary layer. However, VFR
CIGS (030-035 AGL) will continue to impact SJS for a another hour
or so into the new forecast period, probably no later than about
20Z. Otherwise, VFR flight conditions are expected outside of the
most sheltered valley areas where fog will develop late tonight
into Wednesday morning. Valley fog is not expected to impact any
terminals at this time. There will be an increase in thin high
level clouds overnight into Wednesday. Light winds are expected
through the period, averaging less than 5 kts but having a
predominant north-northeast flavor in general.
-- End Changed Discussion --

&&

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

$$

UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...VORST
AVIATION...RAY