JKL issues Area Forecast Discussion (AFD) at Nov 21, 12:24 AM EST194
FXUS63 KJKL 210524
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1224 AM EST Thu Nov 21 2024
.KEY MESSAGES...
- Colder with snow showers expected late morning through mid- to
late afternoon today (Thursday).
- A large area of widespread steady light snow develops quickly
late this afternoon or early evening from northwest to
southeast, and continues through much of the overnight. Snow may
mix with or change to drizzle toward morning.
- Snow changes to rain toward midday Friday as warmer air moves
into the area from the west, with the latest changeover at
higher elevations along the Virginia border.
- Locations most likely to receive impactful snow accumulations
are those elevations above 1500 feet, mainly this evening into
the overnight.
&&
.UPDATE...
Issued at 742 PM EST WED NOV 20 2024
Sfc high pressure nosing into the region in between systems has
led to a slackening pressure gradient and some of the deeper
valleys decoupling. This has resulted in some of these valley
areas to cool off faster than the previous forecast. Following
recent rainfall and with the clearing skies and slackening winds,
the potential for at least a period of patchy fog later this
evening or in the overnight has increased before clouds increase
again. Adjustments to hourly visibility, weather, temperature,
and dewpoint grids have been made accordingly.
&&
.SHORT TERM...(This evening through Thursday night)
Issued at 329 PM EST WED NOV 20 2024
We have a very active short term period with multiple rounds of
precipitation and gusty winds at times. We begin the period with a
strong cold front crossing the area this afternoon. This has nearly
eclipsed most of the region now with just parts of far eastern
Kentucky still in the upper 50s to 60s at 2 PM. This front has
packed quite a punch this afternoon, with winds gusting up to 42 mph
here at JKL and many more open and high elevation locations seeing
35 to 40 mph. Given this did increase through winds closer to the
HRRR this afternoon along and ahead of this boundary. However, they
will relent through the afternoon. The latest trends in the
satellite show that there is decent clearing behind the front across
parts of central Kentucky and this will slide into the eastern
Kentucky later this afternoon and into the evening. This will lead
to mostly clear skies tonight before the next wave of energy
approaches by from the northwest bring in low and mid level clouds
by early Friday. Overnight lows will fall into the low to mid 30s.
Thursday, another lob of energy drops southward with a another cold
front. This cold air advection pattern will steepen the low level
lapse rates tomorrow afternoon. This will aid in enhancing the snow
shower potential tomorrow. These rounds of snow showers will be
accompanied by gusty winds at times in the 20 to 25 mph range at
times. Also, heavier snow showers could lead to brief reductions
in visibilities. There is good agreement in the models for this to
be all snow given the wet bulb potential with dewpoints in the
mid to upper 20s through the day. The good news is highs in the
afternoon will be in the upper 30s for most and therefore should
be less impactful for travel given the warm temperatures we have
seen of late. Therefore perhaps some grassy and elevated surfaces
see a dusting to perhaps a quick half an inch. However, fairly low
confidence on seeing much out of this initial round.
Thursday night, Another strong undulation in the mid-level slides
southward Thursday evening. There will also be some support from a
upper level jet streak left exit region giving way to some decent
divergence aloft. The surface reflection in the form of a low
pressure does ramp down as it heads into the Ohio Valley, but
there will still be ample energy for another round of snow to
slide into the area. Overall the profiles will support snow
through the evening and into the night. However, as we move into
the night and overnight the sounding show a warming trend as you
advect some warmer air into the area. You also start to loose the
better ice in the DGZ based on some of the HREF forecast sounding
data toward Friday morning. This will lead to some of this
activity starting to mix to more of the rain/snow late Thursday
night into early Friday morning for most areas outside of the
higher terrain where temperatures will be slower to climb. Right
now, based on temperatures at the surface most locations will
only see snow accumulations on grassy and elevated surfaces.
However, it still looks like locations above 1500 feet would have
a decent shot of snow accumulations on more surfaces with highest
amounts still mainly above 3000 feet. That said, given this no
plans to change or modify the current Winter Weather Advisory.
.LONG TERM...(Thursday night through Tuesday)
Issued at 328 PM EST WED NOV 20 2024
Active weather expected to continue in the extended portion of
the forecast, as a series of low pressure systems move through the
region. The latest runs of the GFS, ECMWF, WPC guidance, and GFS
Ensembles all have similar solutions, with large and well
developed low pressure centered over southwestern New England.
This system will be quite large, and will be impacting an area
that includes New England, the western Great Lakes, the Ohio
Valley, the Mid-Atlantic region, and the central Appalachians.
Rain and showers are expected across eastern Kentucky Friday
through Saturday, as moisture wrapping around the back side of the
eastern low pressure interacts with the terrain of the forecast
area. Light snow accumulations will be possible with this
activity, especially in the higher terrain along the Virginia
border on Friday. Temperatures should warm up enough Friday into
Saturday, to allow snow to change over the rain for all but the
highest ridges along the Virginia border. The precipitation will
linger across far eastern Kentucky through the end of the day on
Saturday, before the upper low moves far enough to our east to
allow the precip to finally come to and end.
A ridge of high pressure will settle over the region over the
weekend, and will bring dry and warmer weather back to the area
Sunday and Sunday night. After this brief respite, another area of
low pressure will barrel through the region late Sunday night and
Monday, and will bring multiple rounds of rain to eastern Kentucky
the first half of the week. This system will develop over the
central Mississippi valley and east central Plains, and will move
quickly into the Great Lakes by Monday night. A surface cold front
extending southward from this system will be our weather maker
through the middle of the week. The latest NBM data suggests that
this boundary might get hung up over our area, and will allow precip
to linger for a couple of days while the front is in place.
Temperatures will be well below normal overall, with several days
expected to max out in the 40s and low to mid 50s. Sunday and Monday
look to be much warmer, with highs in the upper 50s to lower 60s
both days. This will be in response to the persistent southerly flow
that is expected to set up across the region to begin the new work.
As far as weather hazards go, the only thing we'll really be
watching is whether or not enough snow will fall, and if its will be
cold enough, to lead to slick roads on Friday, especially early in
the day in our eastern higher terrain counties along the Virginia
border.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1224 AM EST THU NOV 21 2024
Clear skies with primarily river valley fog will continue to begin
the TAF period. However, clouds and increasing winds will move
quickly southeast through the area between 09z and 13z this
morning, which will end the fog from northwest to southeast.
Winds will reach 20 to 25 kts from the west by midday, with
scattered snow showers expected primarily from near KJKL north
and east especially between 16z and 22z. Low VFR and/or high-MVFR
ceilings will then trend quickly lower to IFR viz and cigs by
00z-01z at most if not all TAF sites as the next system brings
widespread steady snow which will continue through the end of the
TAF period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 7 PM this evening to 10 AM EST
Friday for KYZ087-113-115-117-120.
Winter Weather Advisory from 4 PM this afternoon to 10 AM EST
Friday for KYZ088-118.
&&
$$
UPDATE...JP
SHORT TERM...DJ
LONG TERM...AR
AVIATION...CMC
Source:
JKL issues Area Forecast Discussion (AFD) at Nov 21, 12:24 AM EST---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
