329
FXUS63 KJKL 280539
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
Issued by National Weather Service Wilmington OH
139 AM EDT Tue May 28 2024

.KEY MESSAGES...

- Cooler, drier air will eventually filter into eastern Kentucky
  behind an exiting cold frontal system. Generally cooler and less
  humid weather will then be in place over the next several days.

- Warmer and somewhat more humid weather will return by next
  weekend, with our next area-wide chance of showers and
  thunderstorms.

&&

.SHORT TERM...(This Evening through Tuesday night)

Looking forward to quiet, pleasant weather for this cycle of the
short term. Upper level low over the Great Lakes Region will keep
a mean trough in place aloft across the eastern CONUS. Weak short
wave disturbances will rotate around the southern periphery of the
mean trough, but there appears to be no significant impacts to
speak of over our forecast area through the short term. Drier,
cooler air will gradually filter into eastern Kentucky later
tonight and tomorrow behind an H850 trough, which is passing
through the region, currently entering our western most zones, or
just entering eastern Kentucky.

Sensible weather features seasonably cool afternoons and chilly
nights, especially in our sheltered, typically colder valley
locations. Northwest flow will tend to provide increasingly
clearer sky conditions with a west-northwest gradient wind.
Temperatures will drop into the mid 50s tonight and low to mid 50s
tomorrow night. While guidance keeps our temperature in the 50s,
it is possible some of our coldest valleys could slip into the
upper 40s tomorrow night. Afternoon highs will generally be in the
low to mid 70s tomorrow. No hazards to deal with during the short
term. However, the most recent runs of the hrrr do suggest a new
trend in the forecast for this evening in that there may be some
isolated shower development along the H850 trough this evening as
it passes west to east across the area. Will monitor for possible
updates to our PoPs as necessary.

.LONG TERM...(Wednesday through Monday)

The 27/12Z model suite analysis beginning Wednesday morning shows
an upper level longwave trough over Eastern Canada down across
the Great Lakes and Ohio Valley. An upper level ridge extends from
the Southern Plains northward into Manitoba ahead of another
trough moving ashore the Pacific Northwest. At the surface, low
pressure is found over eastern Quebec with a cold front trailing
back to the southwest around the southern shores of the Great
Lakes. Strong Canadian high pressure is centered over northwest
Ontario behind the front.

The cold front will brush northeast Kentucky on Wednesday
afternoon as it attends the passage of the upper level trough axis
and a lead shortwave. This will bring slight chance/low chance
POPs to locations northeast of KY Route 15. Surface high pressure
then sinks to the Great Lakes on Thursday while additional
shortwave energy continues to rotate through and reinforce the
troughing aloft. This will keep relatively cool, dry northerly
flow in place, holding 850mb temperatures mostly in the 5-10 C
range. The surface high will then shift east Friday along with the
upper level ridge axis while subsiding and weakening. Once the
surface high is off to our east, southerly return flow will bring
increasing moisture levels and warmer temperatures for the first
three days of June. Passing disturbances will interact with this
moisture to bring daily slight chance/chance POPs from Saturday
onward.

In terms of sensible weather, look for sporadic showers to bubble
up on Wednesday northeast of KY Route 15, with the highest
chances ~30% over the Big Sandy Basin. Temperatures will be
seasonably cool with highs in the lower and mid 70s. From
Wednesday night into Friday night, low humidity, cool
temperatures, and fair weather will prevail with northerly
breezes. Look for daily highs in the lower to mid 70s while night
time lows range from the mid 40s to mid 50s. Daily shower and
thunder chances then return over the weekend and early next week
as southerly flow brings rising moisture levels and temperatures
moderating into the lower to mid 80s by Monday, with lows in the
upper 50s to lower 60s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Isolated showers have pushed east and out of southeast Kentucky as
of 06Z, leaving only a diminishing VFR ceiling over the foothills.
Valley fog has formed quickly in the clearing air with light winds
and KSME has quickly dropped to VLIFR visibilities. While this may
bump up and down a little through 12Z, think the trend will be for
this to lock in at the 1/4SM or 1/2SM range much of the night. May
see some brief MVFR fog at KLOZ as well toward sunrise. Winds
overnight will generally be light/variable or calm.

Once heating commences on Tuesday, expect cumulus to form/fill in
rather quickly especially with a weather disturbance pushing
through. Expect a VFR ceiling at most sites by the afternoon
(BKN050 or so) and some quick moving isolated or scattered showers
not out of the question especially at SJS/SYM. Have a VCSH
mentioned during the afternoon at those two sites. Winds may
intermittently gust past 15 knots at any site this afternoon with
good mixing, but highest chances at the northern terminals. Broken
VFR ceilings should hang into the early evening before starting to
scatter out later in the evening especially southern terminals.
Winds should decrease quickly after sunset.

&&

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

$$

SHORT TERM...HAL
LONG TERM...
AVIATION...Binau