666
FXUS63 KJKL 310840
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
440 AM EDT Fri May 31 2024

.KEY MESSAGES...


- Dry weather can be expected today and into Saturday. The next
  system will then begin to impact the region starting late
  Saturday and continuing into Sunday.

- It will become warmer and more humid with chances of showers and
  thunderstorms continuing into the new work week.

&&

.UPDATE...
Issued at 1205 AM EDT FRI MAY 31 2024

Just a quick update to the grids mainly to fine tune low
temperatures and the ridge to valley temperature split through the
rest of the night. Did also add in the current obs and trends for
the T/Td/Sky grids. These minor adjustments have been sent to the
NDFD and web servers along with a freshening of the zones and
SAFs.

UPDATE Issued at 835 PM EDT THU MAY 30 2024

00Z sfc analysis shows high pressure building in from the north
bringing drier and cooler air into the state along with light
winds and clearing skies. This will be another good setup for a
ridge to valley temperature split through the night on account of
radiational cooling. Currently some signs of the split have
started to develop with the valleys running in the lower 60s while
some lower 70s are found on a few of the ridges and in the
more open southwest parts of the area. Meanwhile, amid light
winds, dewpoints are generally in the low to mid 50s along with a
few upper 40s noted in the north. Have updated the forecast mainly
to add in the latest obs and trends for the T/Td/Sky grids along
with some river valley fog. These minor adjustments have been
sent to the NDFD and web servers.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 341 PM EDT THU MAY 30 2024

Highly amplified ridging moves across the forecast area through
Saturday afternoon bringing dry and comfortable weather.

Backdoor cool front has moved into the region from the north on the
downstream side of the high pressure centered to the north this
morning and early afternoon. A reinforcing cool front drops south
across the forecast area and will bring an even drier air mass to
region after midnight tonight and lasting through much of Friday
before modifying late Friday night as return flow begins to usher
increasing humidity back into the region.

With the dry air mass moving over the area tonight, excellent
radiational cooling is expected with widespread lows in the 40s,
with a few lower 40s reading in the typically coldest most sheltered
valleys. Warmer overnight temperatures in the upper 40s to near 60
degrees are expected Friday night as flow aloft begins a warming and
moistening trend. Highs Friday will reach the mid to upper 70s.

.LONG TERM...(Saturday night through Thursday)
Issued at 440 AM EDT FRI MAY 31 2024

Unfortunately this cooler and quiet spell of weather must come to an
end. By Saturday evening/night, the next weather system will begin
bearing down on eastern KY. High pressure and an upper level ridge
will be in place across JKL during the day Saturday, but by Saturday
evening, these will be exiting east of the state. This will allow a
shortwave to make its way into the Commonwealth starting in the
afternoon in the west, and slowly continue east throughout the
evening and overnight. This will be accompanied by a surface low
pressure system which will skirt north of the Ohio River Saturday
evening and night. Much of KY will find itself near the warm front,
with a surge of warm/moist SW flow ahead of the cold frontal
passage. This associated cold front should make it to eastern KY
by Sunday. Showers and thunderstorms are expected along and ahead
of this cold front, with pops moving in from the west and becoming
widespread overnight Saturday night, then continuing into Sunday
before exiting to the east by the afternoon/evening. Thankfully
this shortwave and surface system are not connected to a larger-
scale troughing pattern, so there isn`t going to be a clash in
airmasses and temperature. Therefore, don`t expect much in the way
of severe weather concerns (SPC is also not highlighting it at
this time), and shouldn`t see too much of a temperature drop
behind the departing cold front.

Rather, instead of a cooler airmass setting in, Monday actually gets
warmer as upper level ridging and high pressure set in briefly. The
NBM has temperatures rising well into the low and mid 80s across
eastern KY, some 10 degrees higher than the previous day in multiple
locations. Models are already starting to show disagreement in their
solutions from this point forward, especially when it comes to pops
affecting the region. Therefore, stuck with the NBM, which does
introduce mainly diurnally driven convection, peaking in the
afternoon and decreasing overnight. The better chance for pops may
come Wednesday and Wednesday night, as a large upper level low
tracks across the Canadian border, with an occluded surface low
pressure center and cold front which will make its way across the
state. Didn`t see any reason to deviate from NBM pops through the
extended given uncertainties, but do expect some changes in their
solutions as we get closer.

Temperatures should remain in the low to mid 80s through the
remainder of the period after Monday. Overnight lows are a bit more
interesting. The NBM shows some amount of cloud cover moving across
the region every night of the work week, though not completely
obscuring the sky. There is a lot of uncertainty here. Where and
when and how much these clouds set up will inevitably make an impact
on the overnight temperatures. And because there is chances of
convection just about every day, we won`t get the strong radiational
cooling like we would if we were sitting under strong high pressure
(subsidence) and clear skies. Did put in some ridge/valley
temperature differences, but didn`t go too crazy, since there may
still be quite a bit of variability. Generally expect temperatures
in the upper 50s and low 60s for Sunday night after the frontal
passage, and then in the 60s for the lows moving forward.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 350 AM EDT FRI MAY 31 2024

VFR conditions and light winds are expected through most of the
period. The only exception will be localized valley fog during
early morning and late night hours. However, it is unlikely to
affect TAF sites.

&&

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

$$

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