204
FXUS63 KJKL 160925
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
525 AM EDT Mon Jun 16 2025

.KEY MESSAGES...

- Locally dense fog is favored to develop tonight where skies
  partially clear.

- Unsettled weather will continue through the first half of the
  new week, with showers and thunderstorms expected on most days.

- Repeated rounds of showers and thunderstorms will bring a low-
  end threat of excessive rainfall, with isolated occurrences of
  high water or flash flooding possible into Monday.

- Look for temperatures to climb distinctly above normal for
  daytime highs for the latter part of the new week.

&&

.SHORT TERM...(Today through Tuesday)
Issued at 450 AM EDT MON JUN 16 2025

08Z sfc analysis shows a blob of a low left over Kentucky with a
weak pressure field keeping winds light and the airmass stagnant.
Thus, another night of mild and muggy conditions is underway.
This has led to areas of fog in the clear patches of the clouds -
becoming locally dense. For this, an SPS is in effect through 13Z.
A stray shower or two will be possible into dawn but most locales
will stay dry until later today. Currently, temperatures and
dewpoints are running in the upper 60s to lower 70s, most places.

The models, and their individual ensemble suites, are still in
good agreement aloft through the short term portion of the
forecast. They all depict 5h ridging off to the southeast while a
narrow, but full-latitude trough is pushing east into the Ohio
Valley. This feature brings with it a healthy amount of energy and
a piece of which will break off and work northeast, north of the
Ohio River, in southwest mid-level flow this evening. The passing
impulse and some slight height falls will enhance lift for a time
into the evening over eastern Kentucky. The trough is then slow
to work east tonight into Tuesday maintaining the proximity of its
energy for our area through 00Z Wednesday with its biggest impact
expected for Tuesday afternoon. The relatively small model spread
through the short term period supported using the NBM as the
starting point for the forecast grids with minimal adjustments
needed - mainly to add in some timing details from the latest CAMs
for the PoPs and Wx grids through Tuesday.

Sensible weather features some fog around this morning and then a
period of clearing that sets the stage for instability building
up into the afternoon. Again we can expect scattered to
widespread shower and storm activity developing this afternoon.
This will also mean the potential for training cells bringing
isolated spots of excessive rainfall. Also expect the storm
potential to linger longer into the night then it has recently
owing to that upper wave passing by overnight. For tonight, aside
from the shower and storm threat, we can also anticipate areas of
fog becoming locally dense while temperatures remain warm amid
muggy conditions. For Tuesday, the sfc reflection of the arriving
5h trough looks to push more showers and storms into the area,
especially in the afternoon and evening. Depending on how much
rain we see today and tonight Tuesday will be primed for flooding
so later shifts may need to consider a Flood Watch. Also, WPC has
placed much of our area in the Slight Risk category for excessive
rainfall Tuesday and Tuesday night.

The changes to the NBM starting point were primarily focused on
adjustments to the PoPs per the latest CAMs guidance for timing
and magnitude through Tuesday evening. As for temperatures -
again did not deviate far from the NBM guidance through the period
given the high moisture content.

.LONG TERM...(Tuesday night through Sunday)
Issued at 525 AM EDT MON JUN 16 2025

The main adjustments to the extended were again to restore some
terrain detail to the NBM temperatures each night after Thursday.
Did also keep a threat of showers and thunderstorms around for
Sunday afternoon with some uncertainty as to when return flow will
be enough for renewed convection on Saturday following a dry
Friday. Confidence in the temperatures for the extended is higher
than normal given the NBM guidance came in near the center point
of the PDF spread.

The previous long term discussion follows:

The period will start with the main prevailing westerlies aloft in
rather zonal flow across the Great Lakes and New England, with
a trough in weaker flow extending southward from the Great Lakes
over the lower Mississippi Valley. At the surface, a weak and
decaying, nearly stationary frontal boundary is forecast to be
near the northern edge of the JKL forecast area, with a warm and
humid air mass still in place over our area. The upper trough
will weaken as it approaches on Tuesday, but with the diurnal
heating cycle it should bring another increase in convective
precip. The weak upper trough should finally be moving to our
east on Tuesday night, and along with the diurnal loss of
instability, a more pronounced decrease in precip is expected.

Conditions aloft will be more benign on Wednesday, with weak and
relatively flat flow. At the surface, the prior frontal boundary
should be gone, but another cold front will be crossing the
Midwest and bringing us an increase in low level southwesterly
flow as the pressure gradient tightens in front of it. This front
will be supported by a slightly more significant upper level
trough moving east across the CONUS (moving onshore on the West
Coast on Monday). Without any change in our air mass for
Wednesday, at least scattered showers and thunderstorms should
develop, but probably less coverage than on preceding days. The
cold front and its supporting upper trough are forecast to pass
through on Thursday, bringing another more plentiful round of
showers and thunderstorms.

Behind the front, somewhat drier air will arrive for Friday into
Saturday, but the extent of air mass change is still uncertain.
Regardless, it`s looking to be enough to result in mainly dry
weather from Friday through the weekend. This prospect will be
bolstered by the quick eastward departure of the upper trough and
a large ridge/upper high building/developing eastward into the
area. The rising geopotential heights and warming aloft will also
allow daily sun to warm the air mass, with many locations
potentially breaking 90 degrees for highs by Sunday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 155 AM EDT MON JUN 16 2025

Conditions are in the process of deteriorating early this morning
with fog and low clouds setting in at most sites and VLIFR likely
the end result. This will be the rule through rest of the night
and for a few hours after dawn. Then ceilings and visibilities
will improve late morning into the afternoon, with scattered
showers and storms once again expected to develop. Winds outside
of any storms will be light, around 5 kts, generally out of the
southwest.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...GREIF
LONG TERM...HAL/GREIF
AVIATION...HAS/GREIF