924
FXUS63 KJKL 151205 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
705 AM EST Wed Jan 15 2025

.KEY MESSAGES...

- Light snow accumulations will be possible Saturday night
  through Monday morning.

- Aside from near normal temperatures Friday and Saturday, below
  normal readings are expected for the next week. Apparent
  temperatures could fall to near zero for a few locations
  tonight-- primarily north of the Mountain Parkway. Apparent
  temperatures are also forecast near or below zero for much of
  the area on Monday and Tuesday.

&&

.UPDATE...
Issued at 645 AM EST WED JAN 15 2025

No significant changes to the forecast with just the inclusion of
the latest obs and trends for the T/Td/Sky grids as we are seeing
a few temps near the 0 degree mark. These minor adjustments have
been sent to the NDFD and web servers.

&&

.SHORT TERM...(Today through Thursday)
Issued at 500 AM EST WED JAN 15 2025

09Z sfc analysis shows the past evening`s clipper system has
moved well east of the area with chilly high pressure building in
from the northwest. This cold air mass and radiational cooling
from mostly clear skies has allowed temperatures to fall to the
single digits north and near 20 degrees south. Meanwhile, amid
light northerly winds, dewpoints are quite dry in the single
digits above zero for most places. An SPS has been issued for the
coldest temperatures that have arrived in the north this morning.

The models, and their individual ensemble suites, are in much
better agreement aloft through the short term portion of the
forecast early this morning as they have resolved their
differences with the trough coming out of the Southern Plains
tonight. They all depict broad troughing in place through the
northeast portion of the continent with one core of energy
shifting east off the Mid Atlantic Coast this morning and another
coming east from the central Rockies. This pattern maintains the
low 5h heights over eastern Kentucky along with persistent
cyclonic flow. As the western trough comes east today it will dive
into the Deep South passing mostly harmlessly to the south
tonight but also helping to keep northwest, mid-level flow going
over the JKL CWA. In this regime, the next wave of energy swings
into, and through, the central Appalachians later Thursday
morning into the afternoon. A rebound in heights take place into
that evening as the energy wave moves out of the area to the east.
The very small model spread aloft made the NBM a good starting
point for the forecast grids, though with some adjustment per the
latest CAMs for PoPs on Thursday along with hedging toward the
colder values from the NBM PDF for temperatures.

Sensible weather features a very chilly start to the day -
especially along and north of the Interstate 64 corridor - with
ample sunshine not able to pull temperatures up to freezing most
places - away from the Tennessee border by mid afternoon. After a
mostly clear evening, more clouds arrive tonight in advance of
the next clipper system and this should mitigate the coldest
temperatures - generally in the upper single digits north of I-64.
Flurries are expected in the north towards dawn with even some
light snow possible in the eastern parts of the CWA through early
afternoon Thursday on account of the clipper and upper level
support. Only the barest of accumulations are expected from the
clipper, though, at this point. Warmer temperatures will be
welcomed for Thursday but still definitely holding on the cold
side of normal.

The changes to the NBM starting point again consisted primarily
of tweaking the PoPs and QPF/Snow Amounts per the latest CAMs
guidance for that Thursday morning clipper. Temperatures were
kept on the cool side of the NBM through the period.

.LONG TERM...(Thursday night through Tuesday)
Issued at 359 AM EST WED JAN 15 2025

The forecast period begins a cold front moving through the
Commonwealth. With this system, the NBM favored a little bit more of
wetter solution and opted to keep that as the front moves through
the area before PoP comes to an end by early Friday morning. At this
same time, two upper-level waves will move across the CONUS. The
northerly wave will track through the Upper Plains/Southern Canada.
The southerly wave will eject out of the Four Corners toward the
Central Plains. Once leeside of the Rockies, surface cyclogenesis
will take place with a surface cold front trailing from the
northerly low with the southern system developing in the Mid-
Mississippi Valley along the cold front. Together, these systems
will track eastward throughout the day Friday. The southerly surface
low will move into the Commonwealth with increasing PoP chances
throughout the day. Showers will persist through the weekend before
cold air filters into the region late Saturday night into Sunday.
The transition from rain to all snow will occur rather quickly as
forecast thermal profiles quickly drop below freezing overnight
Saturday. Snow will persist through the day Sunday before beginning
to taper off into Monday. Light snow accumulations will be possible
and Winter Weather Advisories may be needed to cover the winter
weather threats. Lingering snow showers will be possible into next
week as another system moves into the region. Snow showers will
taper off Monday as high pressure builds back into the area.

Surface high pressure will build back into the region late Monday
and linger through the early part of the week. Beginning Tuesday
morning, a surface low will eject off the southern Rockies and track
toward the Deep South. This low will remain largely south of the CWA
but as this system begins to eject and shift to the northeast, the
northwest quadrant of the precipitation shield will clip the
forecast area leading to increased snow chances through the day
Wednesday.

An active forecast period is expected to materialize with
fluctuations in temperatures expected. Highs will climb to mid to
upper-40s for Friday and Saturday before falling back into the 30s
for Sunday and 20s for Monday and Tuesday. Overnight lows will
follow this trend as the period starts in the mid-20s but will warm
into the 30s Saturday morning and then falling back into the teens
ans single digits for Monday through Wednesday mornings.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 705 AM EST WED JAN 15 2025

VFR conditions persists over the region as high pressure builds
into this part of the state. Some high clouds will arrive from the
northwest later tonight. Winds from the north at up to 5 kts will
be the rule through the period, though some LLWS will be possible
in the north towards dawn Thursday.

&&

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

$$

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...VORST
AVIATION...GREIF