118
FXUS63 KJKL 280737
AFDJKL

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

.KEY MESSAGES...

- Hotter weather is expected to make a comeback on Friday and
  Saturday, and may now extend into Sunday, with afternoon highs
  around 90 or in the low 90s and heat index values peaking around
  or in excess of 100 degrees.

- A cold front will likely bring additional rain to the area from
  late Saturday into Sunday. Any storms on Saturday afternoon and
  evening could produce strong wind gusts and heavy rain.

- Another shorter-lived cooldown is anticipated for early next
  week followed by a mid week warm up. Heat indices may reach or
  exceed 100 degrees once again Wednesday of next week.

&&

.UPDATE...
Issued at 1145 PM EDT THU JUN 27 2024

No significant changes to the forecast with just the inclusion of
the latest obs and trends for the T/Td/Sky grids with this update.
These minor adjustments have been sent to the NDFD and web
servers along with a freshening of the zones and SAFs.

UPDATE Issued at 740 PM EDT THU JUN 27 2024

23Z sfc analysis shows an area of high pressure over the Great
Lakes and Ohio Valley that is influencing the weather over
Kentucky. This brought a brief respite from the heat as less humid
air settled into the region. It also made for mainly light winds
from the northeast and clearing clouds through the afternoon.
Currently, temperatures are running in the upper 70s to lower 80s
while dewpoints have fallen into the upper 50s to lower 60s for
most. Have updated the forecast mainly to add in the latest obs
and trends for the T/Td/Sky grids, but also to take out the
earlier showers and thunderstorm chances. These minor adjustments
have been sent to the NDFD and web servers along with a freshening
of the zones, HWO, and SAFs earlier in the evening.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 308 PM EDT THU JUN 27 2024

Differential heating boundary is slowly moving south toward the
Tennessee and Virginia borders. However, this activity is tapping
into some remaining weak instability and moisture, resulting in
isolated showers. Cannot rule out an isolated thunderstorm or two
south of the Hal Rogers Parkway/KY Highway 80 through this
afternoon, but overall the trend through the rest of today will be
for drying and clearing skies.

Heading into tonight, a dry air mass settles over the area under
surface high pressure, with some residual low-level moisture
remaining along the Tennessee border area. This will support fog
formation in the typically foggy sheltered river valley locations
tonight into Friday morning, with lower confidence in fog
formation elsewhere. Lows will generally be in the mid-60s, but a
few 50s are possible in the cooler sheltered valleys.

For Friday, east-west ridging across the Upper Tennessee Valley in
the upper levels is expected. However, a weak mid-level low over
the Deep South will weaken into an open trough and begin moving
toward the area. This will allow for moisture to stream north
across eastern Kentucky through the day. Sufficient moisture and
instability will exist for isolated to widely scattered shower and
thunderstorm activity in the afternoon, with continued low-end
chances (20 to 30 PoPs) into the evening and overnight as a low-
level jet develops and pushes additional moisture north into the
area. This will make the low temperature forecast tricky for
Friday night into early Saturday morning. However, with the warm
advection and moisture transport into the area expect lows to
remain elevated especially on the ridgetops and Bluegrass
locations where lows may remain in the 70s, with some sheltered
valley locations possibly falling to as low as the mid-60s,
especially if there is sufficient clearing despite the increasing
warm advection.

.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 06Z TAFS through 06Z Friday night)
ISSUED AT 310 AM EDT FRI JUN 28 2024

Fog will affect many valley locations through early this morning,
bringing localized IFR or worse conditions. It can`t be completely
ruled out at KSME, KLOZ, or KSJS, but confidence is not high
enough to include it in the TAFs. There is a slight chance of
thunderstorms this afternoon and early evening over south central
and southeast KY, but once again there is not enough confidence in
timing/placement to include it in TAFs. Aside from the fog and
thunderstorms, VFR conditions and light winds are expected during
the period.

&&

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

$$

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