771
FXUS63 KJKL 241836
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
236 PM EDT Mon Jun 24 2024

.KEY MESSAGES...

- A fleeting sampling of drier and somewhat cooler air will be
  noticed today.

- Heat and humidity climbs Tuesday and Wednesday before another
  cold front arrives with a chance at thunderstorms Wednesday
  evening.

- The midweek cold front will be less impressive, with even hotter
  weather expected to make a comeback by Friday and Saturday.

&&

.UPDATE...
Issued at 130 PM EDT MON JUN 24 2024

Freshen up the forecast to add in the latest obs and trends, and
this was a very minor update overall.

UPDATE Issued at 1051 AM EDT MON JUN 24 2024

The surface analysis this morning reveals that a cold front has
moved south of the area and high pressure has pushed into the Ohio
Valley in the wake. This leading to mostly sunny skies and cooler
northwest flow. Outside of some minor updates for the latest obs
and trend this was a very minor update.

UPDATE Issued at 803 AM EDT MON JUN 24 2024

Cold front is exiting into far southwest Virginia at 1145z.
Lingering areas of fog and low cloud cover will lift into a fair
weather cumulus field later this morning and persist into the afternoon.
Going forecast has the current trends well captured and was only
adjusted to incorporate the latest observations.

&&

.SHORT TERM...(Today through Tuesday)
Issued at 416 AM EDT MON JUN 24 2024

Cooler and drier air continues to slowly filter into eastern
Kentucky early this morning behind the passage of a cool front.
Rainfall varied widely from nothing to over an inch. Fog has formed
in many locations, especially in valleys, where rainfall occurred.
Temperatures presently range from the upper 60s in the cooler
northern valleys and in the lower to middle 70s elsewhere. At 730z,
a surface analysis suggests that the poorly defined cold front is
pressing southeast of the Hal Rogers Parkway/Highway 80 corridor. A
500H analysis shows a trough axis extends from the Ottawa Valley
down into the Mid-Ohio Valley/Central Appalachians. Further west, a
positively-tilted, upper-level ridge axis extends from an ~593
dam high centered over New Mexico, northeastward through the
Central Plains into Northern Ontario and is reflected at the
surface by high pressure extending from the Upper Midwest down
into the Mid-Mississippi Valley.

The 500H trough over our region will shift off to the east today
while the upstream ridge axis will drop southeastward and cross the
Ohio Valley late tonight. Precipitable water falling to between 0.6
and 0.8 inch and 850 mb temperatures falling to between 13 and 16C
will allow for a very comfortable late June afternoon. Heading
into tonight, the corresponding surface high crests over the
eastern Kentucky Coalfields around 3z tonight; with weak westerly
return flow commencing by early Tuesday morning and continuing
throughout the day tomorrow. This will buoy 850mb temperatures
back to around 20C by late in the day. The next trough will drop
into the Great Lakes late Tuesday evening/night, sending another
cold front toward eastern Kentucky early in the long-term.

In sensible terms, look for patchy low clouds and fog (especially
in southeastern valleys) this morning. After sunrise, the fog
should lift and the patchy low clouds will become an extensive
cumulus field. It will be cooler and less humid with highs in
lower to middle 80s. Mostly clear skies follow for tonight along
with fog forming in the favored valley locales and low
temperatures in the mid 50s cooler northern hollows to the mid
60s on the thermal belt ridgetops/slopes. Abundant sunshine and
hotter temperatures follow on Tuesday with highs in the upper 80s
and lower 90s. However, moderate dew points in the lower to middle
60s will prevent the heat from being to oppressive -- heat
indices generally peak in the upper 80s to lower 90s.

.LONG TERM...(Wednesday through Monday)
Issued at 235 PM EDT MON JUN 24 2024

A rather active long-term forecast period is expected as there`s
going to be a shift in overall synoptic pattern. The first of a
handful of disturbances is expected to bring a cold front into the
region Wednesday afternoon through Wednesday evening. A couple small
perturbations revolving around a parent trough will favor surface
low development over the Great Lakes with a cold front extending
southwest through the Commonwealth. The SPC has given eastern
Kentucky a marginal risk of severe weather with this boundary as
FROPA is expected mid-day to maximize the potential for instability
building. Forecast soundings have decent severe weather indices in
place across the area. Decently steep low and mid level lapse rates
are in place, instability around 2,500 J/kg in the afternoon is
favorable, PW`s around 2.00" which if materialized could bring some
heavy rainfall but overall the most lacking parameter is the lack of
bulk shear across the region. Low shear values could limit the
overall strength of the storms but not really minimize the potential
for thunderstorms. Also, the potential for increased cloud cover
could limit the ability to increase instability which alone could
limit the coverage of the thunderstorms. Thunderstorms will taper
off from northwest to southeast through the overnight Wednesday but
an H850 shortwave is forecast to develop with a surface feature
riding along the departing cold front. The surface low will keep
shower and thunderstorm chances across the far eastern third of the
CWA through the day Thursday before the whole trough ejects to the
northeast.

Behind the exiting trough, height rises are forecast for
Friday morning. At the surface, high pressure will establish itself
and persist through the day Friday and half of Saturday before
another upper-level wave dives southeast out of western Canada and
approaches the Great Lakes dragging a cold front through the
Commonwealth from Saturday night through Sunday with another
perturbation providing a renewing shot of showers and thunderstorms
Sunday into Monday. High pressure will build back into the region
for the end of the period. Overall, the entire period will be
highlighted by multiple rounds of showers and thunderstorms with
high temperatures remaining in the mid-80s to low-90s and overnight
lows in the upper-60s to mid-70s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 120 PM EDT MON JUN 24 2024

High pressure at the surface will keep the period mostly VFR.
There is a cumulus field that is set up across the area leading
to cloud bases around 3 to 4 kft. Outside this we could see a
little mist or fog tonight in the valleys mainly, but this could
develop at SME/LOZ later tonight in the MVFR range. However, this
will lift around 12z to 13Z Tuesday and VFR conditions will be the
story for the remainder of the period. The winds will be out of
the north and west through the afternoon generally 5 knots or less
and will become calm this evening.

&&

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

$$

UPDATE...DJ
SHORT TERM...GEERTSON
LONG TERM...VORST
AVIATION...DJ