-- Discussion containing changed information from previous version are highlighted. --
655
FXUS63 KJKL 171904
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
304 PM EDT Mon Jun 17 2024

.KEY MESSAGES...

- Hot weather persists through the week. Afternoon heat indices
  may peak around 100 at some locations through Tuesday.

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

&&

.SHORT TERM...
-- Changed Discussion --
(This evening through Tuesday night)
Issued at 304 PM EDT MON JUN 17 2024

Current surface analysis has yesterday`s slow moving warm front off
to the east of the area. Surface high pressure is firmly entrenched
across much of the southeastern CONUS. To the north, a shortwave is
moving through the Great Lakes but with the strength of the upper-
level ridge, that feature will remain well north of the area.

For the remainder of the day, near to or record setting temperatures
are forecast to continue to climb into the low to mid-90s with heat
indices pushing 100 degrees. Continued caution and heat safety
awareness should exist as these above average temperatures will
remain in place through the period. Also, increased moisture across
the area will allow for the development of showers and thunderstorms
this afternoon which may linger the evening before dissipating after
sunset. SPC mesoanalysis is pinging the region for SBCAPE values
pushing in the 3,000 J/kg range with PWs approaching 2.00" both of
which could create some decent thunderstorms with heavy rainfall.
Like yesterday, unfavorable severe parameters exist; therefore,
severe thunderstorm chances should be limited. Once showers
dissipate, lingering cloudy skies will remain overnight which will
limit the amount of ridge-valley splitting and hinder fog
development. However, areas that do see precipitation would be the
better candidates to experience fog. As a result of increased cloud
cover, overnight temperatures are forecast to be on the more mild
side as overnight lows are forecast to be in the upper-60s to lower-
70s.

High pressure persists into Tuesday with very similar temperatures
and heat indices to Monday. The big difference for Tuesday is the
decreased moisture due to downsloping from easterly flow will
largely negate the chances for afternoon showers and thunderstorms.
However, can`t rule out a very very isolated chance of PoP for
Tuesday afternoon mainly for the western portions of the CWA. Cirrus
clouds are forecast to be in place Tuesday night into Wednesday
morning which may allow for a ridge-valley split to materialize and
valley fog to develop. However, this is dependent on the cloud
coverage and amount of radiational cooling that can occur.

.LONG TERM...(Tuesday night through Sunday)
Issued at 310 AM EDT MON JUN 17 2024

Models are in good agreement for the pattern that will impact our
area during the long term period. Strong upper level high pressure
is expected to be centered over the Mid Atlantic states Tuesday
evening. Depending on the model, this high drifts northeast to
southern New England or just south on Wednesday, but maintains
strong ridging west-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 somewhere between our
vicinity and the Southeast US coast. 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. Models also hint at an upper trough moving across
the northern half of the country into the Great Lakes region late in
the weekend or early next week, which will likely push a cold front
east across the country and toward the Ohio Valley either Sunday or
Monday of next week. For now, will carry gradually increasing chance
generally 30 to 50) PoPs from Sunday morning through Sunday
overnight to reflect the uncertainty with the timing of the frontal
arrival and resulting showers and thunderstorms.
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&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 125 PM EDT MON JUN 17 2024

VFR conditions are prevailing across all TAF sites and will
prevail through most of the TAF period. Surface high pressure is
in place; however, showers and thunderstorms are forecast to
develop over the next few hours and increase in coverage. Opted to
add VCTS to all terminals through 01Z/Tuesday. As showers
decrease, decreasing CIGS are expected and could lead to areas of
valley fog which could impact all terminals minus KJKL.
Otherwise, light and variable winds will persist through the TAF
period.

&&

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

$$

SHORT TERM...VORST
LONG TERM...CMC/HAL
AVIATION...VORST