569
FXUS63 KJKL 262354
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
654 PM EST Tue Nov 26 2024

.KEY MESSAGES...

- Rain is forecast to return for Wednesday evening into Thanksgiving
  Day.

- Precipitation could briefly mix with or change to snow Thursday
  night before ending with little or no accumulation anticipated.

- Another system is forecast to affect the area this weekend and
  could bring light snow accumulation Saturday evening into
  Sunday morning.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 340 PM EST TUE NOV 26 2024

Satellite imagery shows sunny skies across eastern Kentucky this
afternoon with just a few wispy high cirrus drifting from west to
east. In spite of the bright sun, temperatures are noticeably colder
behind last night`s cold front, ranging in the mid/upper 40s
north of the Mountain Parkway and west of the Pottsville
Escarpment and in the lower/mid 50s further south and east. The
latest surface analysis shows an ~1025mb surface high pressure
situated over the mid-Mississippi Valley under quasi-zonal flow
aloft. A positively-tilted 500H trough axis extends from
Saskatchewan southeastward to off the coast of California.

The surface high crests over the Commonwealth this evening before
shifting off to our east later in the night. Meanwhile, a lee-side
surface low strengthens over northeast New Mexico ahead of the 500H
trough. The surface low tracks east to over Arkansas by Wednesday
evening and then northeastward along a baroclinic zone directly
across eastern Kentucky on Wednesday night. After initially
strong radiational cooling this evening under a robust subsidence
inversion, warm air/moisture advection high/mid-level cloud cover
will rapidly increase toward sunrise and continue to
thicken/lower during the day on Wednesday. Rain chances increase
slowly on Wednesday afternoon before ramping up quickly Wednesday
evening/night with the arrival and passage of the surface low. As
the low passes, southwesterly winds will shift northwesterly,
commencing another round of cold air advection. Storm total
rainfall amounts of 0.3 to 0.6 inches are currently expected.

In sensible terms, mostly clear skies, light winds, and dry air will
allow temperatures to drop quickly into the upper 20s to lower
30s through many of the valleys, with mid 20s in the normally
cooler sheltered hollows. Thermal belts will remain warmest with
lows primarily in the mid 30s. Fog formation is likely along the
main stem rivers and larger tributaries. High clouds will
increase rapidly toward sunrise and then continue to thicken and
lower through the day on Wednesday. The clouds will tend to be
thicker in the northwest, where there will also be a slight chance
(15-24%) chance of light rain during the midday and afternoon
hours. Daily maximum temperatures are expected to range from the
upper 40s in the northern portions of Fleming County (e.g.
Flemingsburg) up to near 60 in the deepest far southeastern
Valleys (e.g Whitesburg, Harlan, Middlesboro). Rain chances
spread to the remainder of the area Wednesday evening. The more
sustained rainfall moves into the I-64 corridor after 7 PM EST and
slowly sinks southeastward overnight, tapering in the I-64
corridor late. The previously noted northwest-southeast
temperature gradient will linger through the night such that upper
30s can be expected by dawn Thanksgiving Day in the far northwest
up to upper 40s in the deepest southeastern valleys.

.LONG TERM...(Thursday through Tuesday)
Issued at 216 PM EST TUE NOV 26 2024

An active forecast period is expected as multiple shortwaves are
forecast to move across the area bringing temperature fluctuations,
wind, rain and snow. The first of these systems is expected to be
impacting the forecast area at the start of the period. When we all
wake up Thanksgiving morning, gusty showers are expected to be
occurring as a surface low and cold front are crossing through the
area. As the upper-level shortwave and embedded jetstreak pivot
northeast, the surface low and associated cold front will depart
Thursday night/early Friday morning. Temperatures are forecast to
fall through the day Thursday before as secondary FROPA ushers in
even colder temperatures late Thursday night. Early Friday
morning rain showers could mix with a few snow flurries as
temperatures bottom out in the lower-30s Friday morning. Post-
frontal northwesterly winds will promote CAA limiting the overall
warming on Friday. Highs for Friday are forecast to be in the mid
to upper-30s with a few places squeaking out a low-40 reading.
Also, as a secondary trough dives into the region, increasing
winds will create a blustery day for Black Friday shopping.

Weak high pressure will build into the region for Saturday but will
short-lived as a quick-moving clipper system dives southeast.
With cold air left behind from the Thanksgiving-Black Friday
system, showers associated with this clipper will be mostly in
the form of snow. The progressive nature of a clipper will be on
full display with this system is it moves into the area late
Saturday night and will be out of the CWA by late Sunday night.
Along with this clipper, a few individual ensemble members and the ENS
shift of tails is highlighting the possibility of light
accumulating snow. The path of this system has been very variable
from run-to-run and model-to-model; therefore, using caution with
this system as there`s not high confidence on the path or the
possibility of accumulating snow. The trough responsible for the
clipper will remain over the eastern CONUS through the end of the
forecast period. As a result of the persistent northwesterly flow
and potent CAA, high temperatures through the end of the forecast
period won`t climb out of the 30s with overnight lows staying in
the teens to lower-20s.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 654 PM EST TUE NOV 26 2024

Mainly VFR conditions are expected through the period. Won`t rule
out a bit of valley fog in southeast KY overnight, but it
shouldn`t affect TAF sites. Winds will be less than 10 kts.

&&

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

$$

SHORT TERM...GEERTSON
LONG TERM...VORST
AVIATION...HAL