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011
FXUS63 KJKL 051933
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
333 PM EDT Wed Jun 5 2024

.KEY MESSAGES...

- Showers and thunderstorms will affect the area today and
  tonight.

- Relatively cooler and drier weather will arrive behind a cold
  front passing through eastern Kentucky on Thursday.

&&

.UPDATE...
Issued at 1055 AM EDT WED JUN 5 2024

Convection, mainly just showers continue to move northeast across
the region in association with a lead disturbance shortwave
trough moving across the Commonwealth and the TN Valley and ahead
of the main 500 mb trough which is nearing the Lower OH Valley.
Lightning activity has been minimal so far, though as we approach
peak heating, lightning will be commonplace. Due to persistent
clouds, CAPE is lower today as compared to yesterday with shear
still lower end, but about 5KT higher than yesterday, nearer to or
just above 20KT. Moisture is quite substantial, with PW analyzed
in the 1.4 to 1.7 inch range. Although a strong storm or two
cannot be ruled out with a gusty wind threat, locally heavy rain
is the main threat in any areas that pick up multiple
thunderstorms following the rainfall that fell yesterday.

UPDATE Issued at 818 AM EDT WED JUN 5 2024

Adjusted cloud cover for tonight to slow down the decrease in
clouds, as a blend of overnight model runs suggests clouds will
be slower to leave.

&&

.SHORT TERM...
-- Changed Discussion --
(Today through Thursday)
Issued at 557 AM EDT WED JUN 5 2024

A strong upper low (by June standards) will move east southeast
from Saskatchewan to the upper Great Lakes during the period. An
elongated trough/wave rotating around the south side of the low
was roughly over the Mississippi Valley early this morning, and
will approach our area today and depart to our east tonight. It
will support a weak surface cold front accompanying it. The
approach of the front and upper trough will support showers and
thunderstorms in the warm and moist air present over our area
today into tonight. Precipitation will diminish as the front and
upper trough depart tonight and early Thursday. Models disagree on
how much drying takes place initially behind the front. The
greatest amount of drying will be behind a secondary front which
will be entering the forecast area from the northwest Thursday
evening. Before that happens, models suggest some additional
shower develop on Thursday afternoon as the second front
approaches. Forecast soundings show shallow instability capped in
the mid levels-- convective currents not tall enough for thunder,
but deep enough for precip. As mentioned, there is still some
variance in models regarding the setup ahead of the second front,
and the GFS and HRRR are the most aggressive at generating light
precipitation. Have used a 20% late day POP at this time.

.LONG TERM...(Friday through Wednesday)
Issued at 333 PM EDT WED JUN 5 2024

We begin the period quiet, as cold front will have passed through
the area. In the mid-levels, we see a low set up near the Great
Lakes and high set up in the Southern Plains, with solid agreement
in the ensembles and deterministic guidance. This will lead to
west to west northwest flow at the surface and much drier airmass.
This will usher in an airmass that will lead to highs in the
upper 70s to lower 80s, which is right around normal for this time
of year. This drier weather will extend into Saturday with with
highs sticking around 80 degrees.

By later Saturday into Sunday, there is good agreement on
increasing moisture, as the the mean of the EPS/GEFS/GEPS ensemble
models show PWAT increasing toward the 1 inch range. This will be
ahead of another southward moving frontal boundary, the a low
forms on near the Lower Ohio Valley. This will spark of showers
and perhaps a few thunderstorms Saturday night into Sunday, with
peak chances on Sunday in the 30-50 percent range.

In the wake of this weaker front, we don`t see quite as much of
moisture drop off and given a mid-level trough axis hangs around
during this time. This could lead to additional chances of showers
and thunderstorms on Monday at around the 30-40 percent chance
range. The the guidance begins to show divergence in the mid- and
upper level pattern. The leads to a fair amount of uncertainty in
the forecast for Tuesday into Wednesday. So we will continue to
see small chances (around 20 percent or less) of showers and
thunderstorms mainly Tuesday and Wednesday afternoon. It looks
like much of the period we will see afternoon highs near normal in
the mid to upper 70s in most cases.
-- End Changed Discussion --

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 214 PM EDT WED JUN 5 2024

Showers and some thunderstorms were moving across the region at
issuance time as a disturbance works across eastern KY. Periods
of reductions to MVFR and IFR and with the heaviest showers
briefly to around airport minimums. Thunder on station is most
probable in the first few hours at JKL, KSYM, and KSJS. This
initial round of showers and thunderstorms will move across the
area over the first 3 to 4 hours of the period, before a likely
brief lull. Another round of showers and thunderstorms in
association with the next disturbance and cold front is expected
during the 00Z to 12Z timeframe. However, the predictability of
timing these beyond the first 3 to 5 hours of the period is too
low to specify it in the TAFs, and VCTS has been used after that
point. Winds will average south to southwest at 10KT or less
through the first 12 hours of the period, before winds become more
westerly to end the period behind the front. Some gusts as high as
25 to 30KT may occur with the stronger thunderstorms.

&&

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

$$

UPDATE...JP
SHORT TERM...HAL
LONG TERM...DJ
AVIATION...JP