616
FXUS63 KJKL 191545 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1045 AM EST Sun Jan 19 2025

.KEY MESSAGES...

- Accumulating snow will last into this evening ending later tonight.
  Highest accumulations are expected in far eastern parts of the
  area.

- Snow squalls will be the primary concern for this afternoon.

- Apparent temperatures will fall to below zero for much of the
  area late tonight and again Tuesday night into Wednesday
  morning.

- Temperatures will gradually begin to moderate back toward
  normal during the latter half of the week into next weekend.

&&

.UPDATE...
Issued at 1045 AM EST SUN JAN 19 2025

15Z sfc analysis shows the main area of low pressure east
southeast of Kentucky with its deformation zone of steadier
moderate snow starting to shrink east through this part of the
state. Light snow remains behind into the afternoon and then we
turn to the snow squall potential which still looks to be a solid
concern per the latest CAMs. These intense snow showers will be
brief in their passage but could lay down an extra half inch or so
of snow in 10 to 15 minutes along with severely reduced visibility
in gusty winds. The afternoon and early evening portion of the
forecast has been tailored for this threat. The Winter Weather
Advisories and Winter Storm Warnings continue. We have seen
reports of as much as 2 inches, so far, with the JKL office
closing in on that mark currently. Also, reports of traffic
accidents and road closures have been filtering into the office.
It is wise to stay off the roads today, if possible. Otherwise,
temperatures are generally in the mid to upper 20s with just a few
low 30s holding on in the far east. Dewpoints, meanwhile are
generally in the low to mid 20s - except a notch higher in the far
southeast. The arctic front appears to be pushing into the
Louisville area at this time with winds picking up from the north
northwest at around 10 mph with gusts up to 20 mph. Northwest
winds at 5 to 10 mph with some higher gusts are preceding this
boundary for eastern Kentucky late this morning. The arctic front
will serve to help kick off those afternoon snow showers and
squalls due to the steeper lapse rates that follow and a
connection to Lake Michigan moisture. The forecast grids have this
in hand along with falling temperatures for the latter part of
the afternoon. The latest obs and trends have been included in
the T/Td grids, as well. These adjustments have been sent to the
NDFD and web servers along with a freshening of the zones, HWO,
WSWs, and SAFs.

UPDATE Issued at 730 AM EST SUN JAN 19 2025

An update has been sent mainly going more aggressive on PoPs
through this evening. Deformation bands continue to develop across
the area, with more intense snow falling within these somewhat
narrow corridors, with relative minima in snow rates between these
bands. The current snow accumulation forecast is still looking
good.

&&

.SHORT TERM...(Today through Tonight)
Issued at 415 AM EST SUN JAN 19 2025

Adjustments to the forecast were fairly minimal for this morning`s
forecast package. There are still some fairly decent discrepancies
in storm total QPF and thus snow accumulations today. While some of
the more well-known CAMS that make up the HREF warrant a more
conservative snow accumulation forecast, some of the internal
mesoscale models (MPAS and RRFS-EMC models) suggest more robust
amounts than currently forecast for parts of our area. It will
thus be interesting to see how this event unfolds. Nevertheless,
regardless of who sees what the bottom line is that all of our
forecast area is expected to see impactful winter weather today.

The expected evolution of the event and associated uncertainties
remain largely unchanged. An area of deformation roughly along or
near the Virginia border counties will likely yield some heavier
snow rates this morning into early afternoon in association with a
baroclinic leaf ahead of an energetic mid- and upper-level
disturbance rounding the base of a large upper low. Models continue
to suggest another maximum in QPF/snow accumulations within a
second area of deformation to the northwest of this area, but
there is considerable uncertainty as to where (and if) it exactly
develops and how it evolves. Between the two areas may lie a local
minimum in precipitation/snow amounts this morning into the
afternoon. Nevertheless, confidence is still fairly high that the
event will transition to snow showers and snow squalls by late
afternoon, gradually tapering off into the evening.

Temperatures plummet tonight, especially as skies clear from the
west and northwest overnight. Forecast apparent (i.e., wind chill)
temperatures suggest the current Cold Advisory looks good for the
forecast area.

.LONG TERM...(Monday afternoon through Saturday)
Issued at 415 AM EST SUN JAN 19 2025

Models and ensembles remain in good agreement over a long wave
trough covering much of CONUS with a shot of arctic air. For eastern
Kentucky, these effects will be felt as early as Monday morning,
where morning temperatures will be in the single digits across the
area. Wind chills or "Apparent Temperatures" will be dangerously cold
to those exposed for long periods, with apparent temperatures below
zero Monday morning, and as low as -14F along and north of the I-64
corridor. High temperatures for the day aren`t expected to make it
out of the teens. This is 25 to 30 degrees below climatological
normals for this time of year. Winds will be out of the west to
northwest at 5 to 10 mph with gusts to 15 mph, otherwise dry
weather is expected. Monday night lows will be in the single
digits for the 2nd night in a row. Climatological normal lows for
this time of year are in the upper 20s. Apparent temperatures will
be slightly warmer, but will remain in the single digits, with a
few places north of I-64 potentially dipping below zero.

Tuesday, a robust trough axis, extending from Quebec to Mexico, will
move through the state, bringing with it a slight chance of
flurries. 500-mb height rises along with southwesterly winds will
aid in high temperatures reaching into the low 20s. However, winds
veer to northwesterly and eventually northeasterly direction
overnight, bringing colder air back into the area. Lows Tuesday
night are expected to remain in the single digits for a 3rd night in
a row, with a range of 5 above to five below zero. Coldest
temperatures will generally remain north of the Mountain Parkway.

Wednesday and Thursday 500-mb heights will rise in lieu of the
exiting system from Tuesday. Quiet weather is expected each day,
with highs Wednesday in the 20s, rising into the mid to upper 30s,
Thursday. Lows Wednesday night will be slightly warmer than previous
evenings, with lows in the single digits to low teens. Thursday
night lows will finally break out of the single digits, but remain
in the teens for much of the area. While this quiet weather is
occurring across eastern Kentucky on Wednesday and Thursday, another
upper-level low spills over the high amplitude ridge out over
western Canada and CONUS, descending into the Kentucky area, from
Montana. This may lead to sprinkles and flurries Friday and
Saturday. Temperatures look to continue their upward trend both
Friday and Saturday, with low to mid 40s possible by next weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 655 AM EST SUN JAN 19 2025

Widespread snow will continue to develop and intensify this
morning with conditions ranging from low-MVFR to as low as
LIFR/VLIFR. As widespread snow exits to the east toward 18z-20z,
snow showers/squalls will develop and persist into the early
evening before gradually diminishing. These afternoon snow
showers/squalls may be accompanied by gusty winds and brief
whiteout conditions, but outside of that conditions will trend
more toward MVFR conditions, with clearing skies and VFR
conditions beginning to move into the area from the west and
northwest overnight tonight. North winds at generally 5 to 10 kts
to begin the TAF period will become north to northwest at 7 to 12
kts with higher gusts today, with periodic gusts to 20 to 25 kts,
especially within showers/squalls, and generally persisting
through the remainder of the TAF period.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight EST tonight for KYZ044-
050>052-058>060-068-069-080-085>087-104-111-114-116.

Cold Weather Advisory from 7 PM this evening to noon EST Monday
for KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.

Winter Weather Advisory until 9 PM EST this evening for KYZ079-
083-084.

Winter Storm Warning until 3 AM EST Monday for KYZ088-110-113-
118>120.

Winter Weather Advisory until 3 AM EST Monday for KYZ106>109-112-
115-117.

&&

$$

UPDATE...GREIF
SHORT TERM...CMC
LONG TERM...GINNICK
AVIATION...CMC