017
FXUS63 KJKL 170545 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
145 AM EDT Mon Jun 17 2024

.KEY MESSAGES...

- Hot and mostly humid weather persists through the upcoming
  week. Afternoon heat indices may peak around 100 at some
  locations, especially through Tuesday.

- There is also a possibility of thunderstorms on Monday,
  Saturday, and Sunday. The greatest probability is in the
  afternoon and evening hours each day.

&&

.UPDATE...
Issued at 145 AM EDT MON JUN 17 2024

The forecast generally remains on track. Mainly freshened up the
hourly temperatures and dew points, accounting for the latest
trends in the observations.

UPDATE Issued at 1151 PM EDT SUN JUN 16 2024

Convection has died off this evening, right along with the ongoing
the forecast. Did make a few adjustments to the overnight lows,
mainly raising readings a bit, as temperatures have only dropped
off to the low to mid 70s at the typically cooler sites, while
upper 70s to lower 80s are common elsewhere. Otherwise, the rest
of the forecast remains on track, with valley fog likely
developing with time. Updates have been sent.

UPDATE Issued at 903 PM EDT SUN JUN 16 2024

Most convection is on the demise, although a longer outflow
boundary is aligned from east to west north of the Hal Rogers
Parkway, drifting north, along with a few more smaller-scale
boundaries migrating northeast down along portions of the
Cumberland River Valley. As such, will continue to allow for 10-20
PoPs over the next 1-2 hours, before the loss of heating and
diminishing storm-scale forcing puts an end to the convective
cycle for the day. For now, will freshen up the hourly
temperatures and dew points through this evening, incorporating
the latest trends in observations.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 332 PM EDT SUN JUN 16 2024

The latest surface analysis has surface high pressure situated over
New England which is also keeping the weather in eastern Kentucky
warm and dry. To the northwest, a surface low is track across the
northern Central Plains into the Upper Great Lakes. A warm front,
associated with the surface low, is extending all the way to the
Georgia shoreline. Locally, mostly clear skies exists across much of
the region with temperatures climbing into mid to upper-80s
across eastern Kentucky with showers and thunderstorms developing
in Tennessee.

Through the day today, the surface low, mentioned above, will eject
into the Upper Great Lakes and while that occurs, the warm front
will lift northeast into the Commonwealth. With warm frontal
passage, a few showers and thunderstorms could develop but mainly
along and south of the Mountain Parkway. SPC mesoanalysis is
forecasting SBCAPE to increase to around 2,000 J/kg with dewpoints
in the mid to upper-60s which is more than enough to support
convective initiation. However, due to the lack of significant
forcing and lack of shear, not expecting much in the way of severe
weather. Daytime highs in the low to mid-90s with heat indices
approaching mid to upper-90s are expected today. Once the front
lifts out the the CWA, toward the overnight, high pressure will
build back into the region. This will clear skies for the overnight
and allow for a ridge-valley split to develop. However, the lowest
valley temperatures are still expected to be in the 60s. Valley fog
will be possible tonight with the expected clearing; also, wherever
precipitation occurs will have a good chance at seeing some fog
development.

High pressure will persist through the remainder of the period with
high temperatures expected to climb back into the low to mid 90s
with heat indices again approaching the 100 degree mark. Also,
persistent moisture in place will allow for afternoon pop-up
thunderstorms through the evening before storms dissipate for the
overnight. Lingering cloud cover may limit the overall ridge-
valley split and fog potential for Monday night into Tuesday
morning. Otherwise, a hot and humid forecast with scattered
showers and thunderstorms is expected for the short-term period.

.LONG TERM...(Tuesday through Sunday)
Issued at 350 PM EDT SUN JUN 16 2024

Models are in good agreement for the pattern that will affect our
area during the long term period. Strong upper level high pressure
is expected to be centered over the Mid Atlantic states early
Tuesday. It drifts north to southern New England on Wednesday, but
maintains strong ridging southwestward over the Ohio and Tennessee
valleys. Late in the week the upper level high/ridge shifts back
southward and weakens by the time it reaches the southeast coast on
the weekend. Resulting subsidence and warm temps aloft will help to
keep convection capped at least until late in the long term period.
During this time, large surface high pressure centered offshore will
ridge westward over VA early in the period, and then also drift
south. Our low level flow will emanate from this high, not having
trajectories over the warm gulf, and this will keep dew points from
being too excessive. In fact, dew points are actually expected to go
down a bit for Wednesday through Friday. The limited low level
moisture will also help to reduce the potential for thunderstorms.

As we move into the weekend, our low level flow will have
trajectories coming from further south and this will bring dew
points back up again. At the same time, lower geopotential heights
and slight cooling aloft will occur as light westerly flow aloft
develops. In combination, this may allow for some thunderstorms.
It`s interesting to note that both the GFS and ECMWF showed a
tropical system moving westward onshore in the Southeast and then
recurving over the Ohio Valley. However, there`s not much
confidence for the scenario playing out at that extended time
range. That being the case, with no significant systems to focus
on, a diurnal trend was used with peak POPs (still fairly low) in
the afternoon and evening hours.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 145 AM EDT MON JUN 17 2024

VFR conditions will give way to MVFR or lower visibility
restrictions due to fog development through 12z, mainly affecting
the deeper river valleys. Most terminals will remain VFR. Fog
will burn off through 13z, with scattered convection expected to
occur between 16z and 00z. A general diminishment will take place
after 00z. Will only carry VCTS at all terminals for now, as
confidence in the exact timing and location remains low at this
time. Winds will average around 5 kts or less through the period,
mainly from the south to southwest.

&&

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

$$

UPDATE...GEOGERIAN
SHORT TERM...VORST
LONG TERM...HAL
AVIATION...GEOGERIAN