844
FXUS63 KJKL 211756
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
156 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, especially Thursday and
  Friday.

&&

.UPDATE...
Issued at 156 PM EDT TUE MAY 21 2024

A few pin prick showers have been showing up on radar this
afternoon. Given this will add in a 15-20 percent chance of
showers and thunderstorms through the afternoon.

UPDATE Issued at 1235 PM EDT TUE MAY 21 2024

This afternoon we have cumulus cloud streets developing, with
little vertical growth and this is likely because of the 700mb cap
mentioned in the previous update. Given this, only change made
was updating sky to better portray the developing cloud streets
and blending in the latest obs.

UPDATE Issued at 1029 AM EDT TUE MAY 21 2024

Overall forecast is on track today. Some of the CAM solutions
suggest an isolated shower or thunderstorm is not out of the realm
of possibilities. However, the forecast soundings suggest a
strong cap exists just above 700mb, but afternoon highs in the
upper 80s will be around our convective temperatures. This will be
watched through the afternoon to see if any showers or
thunderstorms can develop. Outside this only minor update to blend
in the latest obs.

UPDATE Issued at 721 AM EDT TUE MAY 21 2024

There are no changes to the forecast with the mid-morning update.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 340 AM EDT TUE MAY 21 2024

Warm advection increases through the short-term period as a strong
cyclone grazes the Mid-Ohio Valley through early Wednesday evening.
With the mid-level jet stream remaining west and northwest of the
forecast area, however, shower and thunderstorm activity will
remain limited.

For today, near-record high temperatures in the mid- to upper 80s
are expected as southerly flow begins to increase (yet remains
light) near the surface and southwest flow increases aloft as upper
ridging remains just to the southeast over the Southeast US. There
appears to enough instability and moisture to justify PoPs of around
10 percent for this afternoon, not quite enough to warrant mention
in the official forecasts (15 is required) for almost the entire
forecast area.

Heading into tonight, a southwesterly low-level jet will impact
the Mississippi and Lower Ohio Valleys, including the Bluegrass
region, just grazing our western and northwestern counties in the
CWA. Therefore, warm and dry conditions are expected yet with
increasing high clouds. Lows will generally be in the upper 50s to
mid to upper 60s, coolest in the deeper valley locations.

Lower atmospheric winds increase Wednesday morning around or just
after daybreak ahead of am impinging cold front into the Midwest,
well upstream of the forecast area. This will help to increase
moisture and instability through the day, especially toward the
Bluegrass region. Have thus kept slight chance to chance PoPs (15
to 40 PoPs) for much of northern through southwestern parts of the
forecast area beginning in the afternoon and extending into the
early evening hours. Warm temperatures continue despite the
increasing warm advection and cloud cover with mid to upper 80s
expected once again.

.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.
&&

$$

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