JKL issues Area Forecast Discussion (AFD) at Nov 11, 2:52 AM EST081
FXUS63 KJKL 110752
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
252 AM EST Wed Nov 11 2026
.KEY MESSAGES...
- A major pattern change begins tonight with the arrival of a
colder air mass that lasts into next week.
- Showery weather returns this evening and lingers through late
Friday under persistent cold advection within a large upper low
over the Eastern US.
- The first snowflakes of the season could fall on Friday as a
much colder air mass moves into eastern Kentucky.
&&
.SHORT TERM...(Today through Thursday)
Issued at 252 AM EST WED NOV 11 2026
A split flow pattern continues across the CONUS with an active
subtropical jet stream from the subtropical Pacific east-northeast
through the Gulf Coast and Southeast US, while an active northern
stream jet stream resides across the northern half of the CONUS. Of
particular note is a a strongly a pair of digging shortwave over the
Central Plains/CONUS and southern Saskatchewan/Manitoba. These
shortwaves will help carve out a deep upper trough over the Eastern
US downstream of a rapidly strengthening upper ridge over the Great
Basin and Northern Rockies.
The initial shortwave will push a cold front across the area this
evening and overnight, bringing a round of showers and perhaps a few
thunderstorms given there could be a few hundred J/kg of SBCAPE
remaining. The most likely timing would be from mid-evening onward
for the arrival of precipitation across our eastern Kentucky zones.
A series of shortwaves then move across the area through the
remainder of the short-term, with the primary upper-level jet
remaining south of the area. This will bring pulses of cold
advection upslope rain shower activity through the day Thursday.
With persistent low clouds and cold advection, highs will only reach
the lower 50s Thursday, and even then these highs may occur during
the early morning hours before sunrise, with daytime temperatures
possibly slowly falling through the mid and upper 40s through the
day.
Manual updates to the grids were to expand PoPs across the area,
especially with the upslope cold advection activity tonight into
Thursday which the NBM tends to underestimate the coverage.
.LONG TERM...(Thursday through Tuesday)
Issued at 319 PM EST TUE NOV 10 2026
At the start of the long term period, midlevel troughing will be
located over the eastern CONUS, with amplified midlevel ridging
over the Intermountain West and High Plains. Farther west, two
closed lows will be located off the Pacific Coast: one near
British Columbia, and another off the coast of California. Closer
to eastern Kentucky, multiple shortwaves will be embedded within
the eastern CONUS trough, with the first shortwave on the eastern
fringes of the forecast area on Thursday morning. At the surface,
an area of low pressure associated with this feature will be
located in the Mid Atlantic region, with a secondary cold front
initially just to our north. This front will progress through
eastern Kentucky during the day on Thursday, with winds becoming
more northwesterly as the front passes. Associated CAA will keep
temperatures below average throughout the day. Thus, expect a non-
diurnal temperature curve during the day on Thursday, with highs
occurring in the morning for most locations (generally in the low
50s), although with the caveat that some frontal timing
discrepancies still exist within deterministic guidance.
More interestingly, this system could bring the first snowflakes
of the season to eastern Kentucky. Rain will be likely during the
day on Thursday as temperatures remain fairly warm (in the 40s and
50s for all but the highest elevations). Multiple shortwaves
should provide ample lift for precipitation on Thursday and
Friday, and upslope flow via northwesterly post-frontal winds
should also enhance these chances, particularly given the
deterministic model signal for this flow to interact with a
moisture plume originating from Lake Michigan. Given this
favorable setup, PoPs were manually increased from the NBM
baseline, with the greatest PoPs in the high terrain of
southeastern Kentucky. By Friday morning, cooler air aloft could
support the transition to a mixture of rain and snow for much of
the forecast area, although with relatively warm surface
temperatures, rain should still be the primary precipitation type
in most locations, except in the highest terrain. Some winter
precipitation could linger in far eastern Kentucky on Saturday,
although PoPs should decline beyond this point as heights rise and
a drier pattern sets in.
A calmer pattern will return by Sunday, with tranquil weather
expected through the remainder of the period. Aloft, the ridge
initially over the Intermountain West will shift east as the
aforementioned Pacific systems move onshore, with the original
deep trough now east of the forecast area. Thus, at the surface,
high pressure will set in, with dry and uneventful weather
expected. High temperatures will trend warmer under the influence
of aforementioned height rises, though winds will still maintain a
light northerly component around the surface high, keeping maxTs
near to slightly below average for this time of year despite ample
sunshine. Overnight, lows will be cool, falling into the 20s in
many valley locations.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1205 AM EST TUE NOV 11 2026
A ridge of sfc high pressure was centered across the Appalachians
to begin the period with VFR observed. The high will remain in
place across the Appalachians tonight before it weakens and shifts
east and a low pressure system approaches from the west. Valley
fog may affect locations along the larger creeks, rivers, and
lakes between about 04Z and 14Z, with MVFR to potentially localized
IFR, or worse, conditions. This is still not expected to affect
any of the TAF sites, however. Moisture will begin to increase at
high and then mid levels by 18Z and after to end the period and
some high and then mid level clouds will begin to arrive from the
west before 00Z. As the cold front nears, low clouds and showers
are anticipated to arrive during the last 6 hours of the period.
Some reductions to MVFR or briefly lower conditions are probable
during the last 6 hours of the period. Winds will average 10KT or
less generally from the south to southwest, with winds likely
trending more westerly at the end of the period in the west. A few
gusts of 20KT or more cannot be completely ruled out in showers
late in the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CMC
LONG TERM...FAGAN
AVIATION...JP
Source:
JKL issues Area Forecast Discussion (AFD) at Nov 11, 2:52 AM EST---------------
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