723
FXUS63 KJKL 211908
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
308 PM EDT Tue May 21 2024

.KEY MESSAGES...

- Dry weather is expected area wide through Wednesday morning.
  High temperatures may approach or exceed record levels this
  afternoon.

- There is a potential for showers and thunderstorms at times from
  Wednesday afternoon through Monday.

- Very warm temperatures will persist through Wednesday. An
  increase in clouds and the possibility of rain will bring
  somewhat lower temperature after that.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 308 PM EDT TUE MAY 21 2024

The afternoon surface analysis shows high pressure is posted up
along the Mid-Atlantic coast. Meanwhile, a low pressure and cold
front is pushing into the Midwest. In the mid-levels, a shortwave
trough axis is pushing eastward into the Midwest. We see subtle
mid-level height rises in the Lower Ohio Valley ahead of this
negatively tilting trough axis. This shortwave ridging will keep
our weather mostly quiet through the afternoon into tonight.
However, an isolated (chances of rain around 15-20 percent) shower
or thunderstorm remains possible through the afternoon before we
loose the diurnal heating and perhaps a weak shortwave noted
pushes east. After this, expect mostly clear skies to prevail
tonight, with some patchy to areas of fog mainly along the river
valleys late tonight into Wednesday morning.

Wednesday, the previously mentioned cold front will move eastward
toward the Ohio Valley late tonight into Wednesday. There is decent
agreement in the ensembles and deterministic guidance that
another low will develop along the weakening frontal boundary.
Particularly, as another shortwave is noted in the mid-levels
pushes east. However, the better height falls in the mid-levels
comes later in the day. Given the nearby cold front and some
shortwaves riding through the flow expect shower and thunderstorm
chances to increase through the day, with rain chances increasing
to 20-50 percent in the afternoon. SPC does have a risk of some
scattered severe weather for Wednesday, but overall the risk seems
low. However, if we can build some instability in the 1000-2000
J/kg of MUCAPE you would have decent kinematics to work with, as
effective shear climbs to around 30-40 knots. The best chance of
stronger storms would be generally along and north of the
Mountain Parkway. The main threat would be an isolated damaging
wind threat. We will not be as warm as the last few days owing to
cloud cover, with highs climbing into the lower to mid 80s in most
cases. Wednesday night, the diffuse cold front will stall out
nearby, with showers and thunderstorm chances continuing into the
night. Particularly given many of the CAMs, ensembles and
deterministic models show a shortwave trough riding through the
flow. This will lead rain chances around the 30-60 percent range.

.LONG TERM...(Wednesday night through Monday)
Issued at 425 AM EDT TUE MAY 21 2024

Still seeing pretty good agreement amongst the models regarding
the flow pattern aloft in the extended. A large, broad trough of
low pressure is currently being forecast to spin its wheels over
the western third of the CONUS to begin the period. Smaller scale,
fast moving short waves are progged to migrate eastward from the
larger upper trough as it spins in place to the west. We will see
rounds of showers and storms firing across the area, as each short
wave moves through the region and interacts with the ample
moisture and instability that will be in place. The western trough
will eventually be displaced to the east later in the period, as
ridging aloft begins building into the western and southwestern
portions of the CONUS, and shifts the entire unsettled pattern
eastward with time. The highest probability for thunderstorms
will be during the afternoon and evening hour each day Thursday
through the first of the new work week. At this time it appears
that although there will be plenty of moisture and instability in
place to consistent allow for thunderstorms, the anticipate wind
shear looks like it will be too weak to support any sort of severe
weather at this time.

There is still a very low chance that portions of eastern Kentucky
could receive excessive rainfall on Friday that could lead to
isolated hydro issues around the area. With persistent widespread
clouds in place, we should see mild and generally uniform nightly
temperatures across the area, with no discernible ridge valley
differences expected. We should see daytime highs reaching the
upper 70s and lower 80s each day, or 2 to 5 degrees above normal
on average. Nightly lows should fall into the low to mid 60s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 132 PM EDT TUE MAY 21 2024

We are seeing cumulus cloud streets this afternoon and even a pop
up very isolated shower. The TAF site is expected to remain VFR
with perhaps a few cumulus bases nearing MVFR through the
afternoon. Then we will loose any cumulus as daytime heating
relents this evening. The winds will remain light as 5 knots or
less in most cases. This increases some Wednesday after 15Z to
generally less than 10 knots out of southwest.

&&

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

$$

SHORT TERM...DJ
LONG TERM...AR
AVIATION...DJ