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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 170231
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1031 PM EDT Tue Apr 16 2024

.KEY MESSAGES...

-- Changed Discussion --
- Chances for showers and a few storms are in the forecast tonight
  through Wednesday night, and also Thursday night Friday evening.
  Chances peak Wednesday and Wednesday night when the strongest
  storms are possible.

- Well above normal temperatures will be in place over the area
  through Thursday, with readings peaking in the upper 70s to low
  80s each day, or about 10 degrees above normal. Cooler weather
  follows for the weekend.
-- End Changed Discussion --

&&

.UPDATE...
Issued at 1026 PM EDT TUE APR 16 2024

Made some tweaks to PoPs and Sky grids through the remainder of
the overnight period, with a continued general increasing trends
in PoPs and cloud cover through the period. Also blended in
latest hourly temperature trends.

UPDATE Issued at 740 PM EDT TUE APR 16 2024

No update needed for early this evening. Will wait until the late
evening update to make any needed changes to PoPs for the
overnight once 00z models come in.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 518 PM EDT TUE APR 16 2024

Short wave ridging is transiting the area this afternoon and
evening, with heights falling again by midnight with the approach
of a mid/upper level low and associated trough tracking through
the Upper Midwest and Ohio Valley. This trough will pass through
the Commonwealth Wednesday and through the Ohio Valley Wednesday
night. At the surface, a frontal zone positioned along the Ohio
River will lift northeast tonight, leaving our forecast area in
the warm sector of the approaching storm system. This system`s
cold frontal boundary will reach our forecast area by tomorrow
evening, and pass through eastern Kentucky Wednesday night.

Sensible weather features continued warm conditions through the
short term, with overnight lows running 5 to 15 degrees above
normal. Afternoon highs tomorrow will be a bit cooler than today
due to rain and a greater expanse of cloud cover, but at around 80
for highs, this will still be about 10 degrees above normal. PoPs
increase late tonight into Wednesday morning, but then fade away
through the day as the surface front loses support and forcing.
Most recent operational models suggest the boundary may stall out
over eastern Kentucky at the end of the period.

Most likely hazards through the short term will be the potential
for strong or severe thunderstorms. The Storm Prediction Center
has eastern Kentucky in a Marginal risk for severe weather
Wednesday into Wednesday evening. The environment appears more
conducive for strong storms very late in the day or better yet
Wednesday evening as the cold front passes through the area. It
appears MUCAPES climb to between 1000 and 1500 J/kg and effective
shear increases to 30-35 kts over portions eastern Kentucky ahead
of the front. Thus the initial round of showers and thunderstorms
late tonight into the day Wednesday will lack the better
ingredients for hazardous weather. By the time the environment
becomes better for storms, the cold front may be already bearing
down on the forecast area. Thus the threat of severe weather
appears quite conditional, depending on timing of the boundary
through the area and especially whether enough time remains for
the atmosphere to destabilize again after morning convection.

.LONG TERM...(Thursday through Tuesday)
Issued at 417 PM EDT TUE APR 16 2024

The period begins with the mid-level short wave toward the
Midwest and a surface low developing and moving northeast along
the cold front toward the Midwest. Meanwhile, in the Ohio Valley
ensembles and deterministic guidance show good indication of mid-
level height rises and warm front lifts northward as the
previously mentioned low tracks northeast. Given the rising
heights and mostly sunny skies we will see afternoon high
temperatures soar into the upper 70s to lower 80s on Thursday,
with ensembles showing about a 30 to 40 percent chance of greater
than 80 degrees for highs. The 80s don`t seem to hard to achieve
given the ensemble and deterministic forecast soundings showing
dry lower level. Then unsettled weather moves east, as guidance is
in good agreement on the front advancing eastward Thursday night
into Friday. This will lead to a 70 to 80 percent chance of rain
Thursday night, with about a 20 to 40 percent chance of
thunderstorms. There is some question as to how much instability
we can maintain through the evening and overnight that leads to a
fair amount of uncertainty on if we could see a stronger storm.
The shear isn`t the best, but effective shear is still around 30
to 35 knots which could lead to some organization. SPC does have a
portion of the CWA in the marginal risk and that seems reasonable
given the fair amount of uncertainty.

Friday, the cold front will advance eastward across eastern
Kentucky by Friday afternoon, as a high pressure noses eastward
from the Plains. The winds will veer from the southwest to
northwest through the day. The chances of rain through the
afternoon will be around the 60 to 80 percent range. This cold air
advection, clouds, and rain early in the day will lead to highs
in the upper 60s to lower 70s. The showers and perhaps
thunderstorm could extend into the evening, but this should tapper
off quickly into the 20 percent range. This as high pressure
continues to nose east into the Ohio Valley and will lead to dry
weather through Saturday night. The question in terms of frost
would be if we can clear out enough or long enough Saturday night.
Given this opted to keep out of the grids for now.

The ensembles and deterministic begin to diverge a bit on a
southern stream system by Sunday. The NBM keeps a small chance of
PoPs in the far southeast, but some guidance suggest it will be
dry Sunday and even if most of the CWA will remain dry. Then high
pressure finally builds east across the Ohio Valley and a
shortwave advances southeast into the Lower Ohio Valley where
guidance seems to have better agreement. Once again, we could see
a few 30s in the more sheltered valleys, but uncertainty remains
on if we could see cloud cover. Then yet another mid-level wave
advances east By Tuesday, but once again ensembles and
deterministic diverge, so stuck with slight chance values from
the NBM generally in northeast Kentucky.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 742 PM EDT TUE APR 16 2024

VFR conditions will prevail through the TAF period. There will be
a small chance for a showers and perhaps a few storms through the
late tonight or early Wednesday morning, with this activity likely
weakening or dissipating as it moves into and across the area.
Winds will be southerly in nature, generally around 10 kts or less
with occasional higher gusts, particularly during the morning
through the afternoon Wednesday. Some LLWS will be possible late
tonight from the south to southwest at about 40 kts as well.

&&

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

$$

UPDATE...CMC
SHORT TERM...RAY
LONG TERM...DJ
AVIATION...CMC