-- Discussion containing changed information from previous version are highlighted. --
661
FXUS63 KJKL 281413
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1013 AM EDT Fri Jun 28 2024

.KEY MESSAGES...

- Hot and humid weather will return for today and Saturday, with
  afternoon highs around 90 and heat indices peaking around 100 in
  some places.

- The heat and humidity could fuel a few thunderstorms in south
  central and southeast Kentucky this afternoon and evening. There
  is a better potential for thunderstorms area wide Saturday into
  Sunday as a cold front approaches and moves through. A few
  storms on Saturday afternoon and evening could produce strong
  wind gusts and heavy rain.

- Another shorter-lived break from the heat and humidity is
  expected on Monday behind the cold front, quickly followed by a
  return of sultry conditions.

&&

.UPDATE...
-- Changed Discussion --
Issued at 1012 AM EDT FRI JUN 28 2024

Made some tweaks to include spotty areas of 15 or greater PoPs
across the forecast area this afternoon into tonight. Models show
sufficient moisture and instability to generate spotty isolated
precipitation. However, fairly strong capping aloft should keep a
lid on the atmosphere and prevent any shower from growing into a
thunderstorm. However, some CAMS indicate this cap may
sufficiently weaken temporarily late this afternoon and early
this evening, enough so where an isolated thunderstorm or two can
not be completely discounted.

Other changes were minimal, and were mainly to blend current
observations with the forecast through the remainder of the
morning.


UPDATE Issued at 704 AM EDT FRI JUN 28 2024

Morning lows in valleys are not quite as cool as was expected. The
milder readings have been blended into the morning temperature
rebound.
-- End Changed Discussion --

&&

.SHORT TERM...(Today through Saturday)
Issued at 445 AM EDT FRI JUN 28 2024

Surface high pressure passing by well to our northeast will
provide a fairly comfortable start for today. However, the high
is departing, and as it does our winds will turn from the east to
the south today and carry in warmer and more humid air. This will
result in a much more uncomfortable finish to the day. It could
also fuel a few thunderstorms. The best chance will be in south
central and southeast KY, but even there the POP is only around
20% due to a lack of significant feature either at the surface or
aloft. Any thunderstorms will fade out tonight.

A series of shortwave troughs moving through the flow aloft to our
north will develop a broader, progressive trough moving east over
the Great Lakes by late Saturday. This will support a surface cold
front which should lay out from MI southwest to AR and OK by late
Saturday. The approach of the front will result in a better chance
at thunderstorms as heat and humidity build on Saturday. Exactly
how convection plays out is uncertain, with southeastward
propagation of activity initially developing near the front being
a possibility.

.LONG TERM...(Saturday night through Thursday)
Issued at 337 AM EDT FRI JUN 28 2024

The large scale flow pattern aloft to begin the extended will
feature a large and broad trough of low pressure move eastward
through the Great Lakes and New England. To the west, strong
ridging, both aloft and at the surface, will be in place from the
western CONUS to the central and northern Plains. The surface ridge
will be centered over the northern Plains, while the upper ridge
will be located over the northern Rocky`s. A cold front extended
southwestward from the Great Lakes trough will be the focus for
shower and storm activity across eastern Kentucky Saturday night and
Sunday, as it sinks slowly southeastward into the Tennessee Valley.
The front should clear the area by late in the day Sunday, with the
last showers or storms exiting the area by around 0Z Monday. After
that, the northern Plains ridges if forecast to expand and
strengthen, and should make a strong and steady eastward push
heading into the first of the upcoming work week. This ridge will
also push the eastern trough into New England, and on out to sea by
Tuesday.

Dry and much cooler conditions will accompany the ridge, as it
initially settles over the region Sunday night and Monday, as a
cooler air mass moves in. In fact, we will likely see the coolest
temperatures we`ve seen over the past several weeks on Monday, with
forecast highs on that day only in the upper 70s and lower 80s. As
the ridge continues expanding east, the air mass will modify due to
strong subsidence and compressional warming due to sinking air in
the center of the high. Because of this, the cool weather we see on
Monday will be short lived. Highs on Tuesday and Wednesday will
rebound to summer like readings in the upper 80s and lower 90s as we
see mostly clear skies and strong sunshine across the region. The
good news is that dewpoint temperatures should be 15 to 20 degrees
lower Tuesday and Wednesday than what we see on Sunday(dews in the
70s), allowing for much less oppressive conditions, in spite of the
higher temperatures.

After dry weather Sunday night through Tuesday night, another area
of low pressure is forecast to move our way by mid-week. A cold
front extending southward from yet another northern stream trough is
forecast to move through the region Wednesday through Thursday. This
boundary will bring more chances for showers and storms to finish
out the week. After a couple of days with dewpoints in the 50s, we
will see rapid moisture recovery ahead of the approaching trough on
Wednesday. In fact, dewpoints will likely rise into the 60s and 70s
once again Wednesday and Thursday, providing fuel for shower and
storm activity along and ahead of the approaching front. We will see
highs back in the upper 80s and lower 90s Wednesday and Thursday, as
southerly flow pumps warm, moist Gulf of Mexico air back into the
Tennessee and Ohio Valleys.

The forecast concerns will be the potential for locally heavy
rainfall with any storms we see Sunday and Wednesday through
Thursday. The Storm Prediction Center also currently has a Day 4
marginal risk for severe weather for Sunday, so we`ll also be
monitoring the potential for severe weather for far eastern Kentucky
to end the weekend. The good news is that the marginal risk means
there is only about a 10% chance of severe weather occurring
anywhere in eastern Kentucky on Sunday, so not really worth worrying
about at the moment.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 704 AM EDT FRI JUN 28 2024

Fog is affecting many valley locations early this morning,
bringing localized IFR or worse conditions, but it looks like it
will avoid TAF sites. The fog will dissipate by mid morning.
There is a slight chance of thunderstorms this afternoon and early
evening over south central and southeast KY, but there is not
enough confidence in timing/placement to include it in TAFs.
Valley fog is forecast again late tonight, but not at TAF sites.
Aside from the fog and thunderstorms, VFR conditions and light
winds are expected during the period.

&&

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

$$

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