JKL issues Area Forecast Discussion (AFD) at Nov 4, 4:01 PM EST627
FXUS63 KJKL 042101
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
401 PM EST Wed Nov 4 2026
.KEY MESSAGES...
- Rainfall is ongoing across eastern Kentucky this afternoon, with
isolated embedded thunderstorms. This activity will continue
through the evening before exiting east of the state tonight.
- A series of cold fronts will pass through the area between
tonight and Friday. Together, they will usher a drier but
colder airmass into the region heading into the weekend.
- Sunday and Monday mornings could see frosty conditions across
portions of eastern Kentucky, along with some freeze potential.
The coldest temperatures will be in the deeper valleys.
&&
.UPDATE...
Issued at 700 AM EST WED NOV 4 2026
A few showers and sprinkles have crossed the region overnight, with
steadier areas of showers still to the west, southwest, and south of
the region. Areas of showers should gradually develop/spread
east/northeast through the morning to early afternoon as the
approaching system nears and moisture continues to increase. A few
thunderstorms are also possible. Hourly temperatures over the next
couple of hours were updated to reflect some of the decoupled valley
locations.
&&
.SHORT TERM...(Today through Thursday)
Issued at 415 AM EST WED NOV 4 2026
Early this morning, an upper level low was centered in the Upper MS
Valley, with a 500 mb trough south over the Central Conus. A lead
shortwave was moving through sections of the Lower OH Valley to
TN Valley and sections of the southeast. Upper ridging was
centered along the southeast U.S. coast. At the surface, high
pressure was centered along the eastern seaboard, while a sfc low
was centered in the upper MS Valley with an associated cold front
extending south in the MS Valley vicinity. Winds in the lowest
levels, roughly 925 mb and below are southeasterly between these
systems, with winds more southerly to southwest from the 850 mb
level and higher in elevation. A few spotty light showers or
sprinkles have occurred over portions of eastern KY during the
past couple of hours, with more substantial showers upstream over
central and western KY down into western and middle TN and points
south. Winds have gusted as high as the 26 to 36 mph range at the
higher elevation KY Mesonet station locations in Pike County
(2770') and Harlan County (4000') since midnight, with gusts
generally no more than 20 mph elsewhere. A few valley locations
remain decoupled as of 4 AM EST, with mid to upper 50s
temperatures, though most locations have been more mixy or mixed
out. PW is currently analyzed in the 1.1 inch or less to 1.6 inch
range from far southeast to southwest, with more substantial
values to the southeast and west.
Today and tonight, the upper level low should track into the western
to northern Great Lakes and become an open wave and merge with a
trough to the north in Canada. At the same time, the lead shortwave
trough should advance across the Lower OH Valley today and into
the middle OH Valley and east of eastern KY later tonight. The sfc
low should trek to the northern Great Lakes/Lake Superior area
tonight, while the trailing cold front moves gradually east
across the Commonwealth, likely clearing far eastern KY late
tonight. As the shortwave trough and cold front approach, moisture
across the region will increase with PW per the 00Z REFS reaching
around 1.1 inches near the WV border to about 1.5 inches
southwest (88th to 97th percentile) around dawn on Wednesday,
before peaking in the 1.4 to 1.6 inch range (96th to 99th
percentile) this afternoon ahead of the shortwave trough and cold
front.
Widespread rainfall is expected from rounds of showers with this
system that should generally be beneficial following recent dry
weather since mid October. These will arrive in the west first,
toward dawn or shortly thereafter and then gradually spread east
and northeast. Convection should wind down from west to east later
this evening and into the overnight hours. Some thunderstorms are
also possible but instability will be limited with MUCAPE peaking
this afternoon on the order of 200 to 500 J/kg per the RAP. Given
the rather substantial forecast PW values, any training convection
could produce swaths of locally higher amounts. Uncertainty
remains with storm total QPF due to the nature of the convection.
NBM based QPF ranges from around 0.25 inches downwind of the VA
border to as much as 0.8 to 1.1 inches in the west and southwest.
00Z REFS mean QPF is around 0.4 inches downwind of VA border
counties (due to downsloping effects at least initially) to around
0.8 in sections of the west and northwest. Higher end event total
rainfall, 00Z REFS 95th percentile values are generally an inch
or more with around 2 inches on the high end in the JKL CWA. Max
amounts are in the 2 to 3 inch range. HRRR runs at times have also
have also had some swaths of higher amounts into the 2 to 3 inch
range for totals. The 06Z HRRR has a bit lighter swaths in or near
the JKL CWA of just under 2 inches. As for FFG values, they are
generally in the 1.5 to 2.25 inch range for 1 hour, with a few
areas over 2.5 inches in the southwest. 3 hour FFG is generally in
the 1.8 to to 2.5 inch range with some higher values in the
southwest, while FFG values in the 6 hour range were mainly in the
2.4 to nearly 4 inches. Based on the 00Z REFS, max 1 hour
rainfall was in the 1.1 to 1.25 inch range while max 6 hour
rainfall was in the 2 to 2.5 inch range. Even if the max values
materialized over the shorter time steps, these would generally
fall below FFG guidance values. Rainfall rates could be sufficient
for some ponding of water on roadways, particularly as leaves
fall and could result in some clogging of ditches and culverts in
some areas. WPC has placed all but the far southeast in a Marginal
ERO for Day 1.
Another concern will be as the rain tapers off from west to east and
mid and high clouds diminish, will be the development of either fog
or low stratus. The higher resolution models generally have some
saturation below 850 mb to end the period. For now have continued
patchy valley fog to areas of valley fog in the grids, with lower
than average confidences if this is more of stratus event or a
bit of a mix of valley fog and stratus pending geographic
location.
On Thursday, eastern KY should remain in southwest flow aloft with
the 500mb trough axis progged to extend from James Bay into the
Great Lakes to portions of the Plains. The column should continue to
dry on Thursday, with PW falling from around 0.9 inches east to 0.6
inches west at dawn per the 00Z REFS to roughly 0.5 to 0.65 inches
or the 50th to 60th percentile by early Thursday evening. Weak sfc
high pressure should build in behind the front into the Lower OH and
TN Valleys on Thursday. A trend of drier weather with decreasing
clouds by the afternoon is expected.
.LONG TERM...(Friday through Wednesday)
Issued at 352 PM EST WED NOV 4 2026
The extended period of the forecast begins on Friday, as an upper
level low will be sinking southward from the Upper Great Lakes
region into the northern Ohio Valley throughout the day. The ECMWF
shows some precipitation on the southern extent of this low,
reaching northern Kentucky and possibly our far northern CWA.
Meanwhile, the GFS keeps us more dry other than some very brief and
light rain potential in the evening. This run of the NBM included
increased cloud cover and some very slight pops across the northern
CWA from 12 to 18Z, but nothing more. Will be interested to see how
the models, and therefore the NBM, trend with the next few runs - as
it could increase the pops throughout the day, or could end up being
a dry day across our CWA. Either way, the impacts from any rain will
be minimal and should only affect the northern CWA.
The upper level low will then continue to track east-southeast
towards the New England coast through the weekend, placing Kentucky
in the northerly flow portion of the system by Saturday. This,
coupled with strong high pressure and northerly flow at the surface,
will result in clearing skies and also a strong push of CAA. While
the current grids don't reflect it just yet, expect a decently
strong ridge/valley split in temperatures on both Saturday night and
Sunday night, with locations, especially deeper valleys, dropping
into the 20s. If this pans out, we will see our first hard freeze of
the season, effectively ending growing season.
Surface high pressure and weak NW flow aloft will remain in place
across the region through the rest of the period, Monday through
Wednesday, bringing with it dry and sunny skies, along with light
winds. Temperatures will warm ever so slightly after Sunday, but
should generally remain in the 60s for highs and 30s for lows.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 111 PM EST WED NOV 4 2026
Conditions vary between MVFR and VFR criteria at the time of
issuance, but MVFR conditions should spread to all terminals as a
cold front approaches the area this evening. This front will
bring widespread rain showers to the region, with occasional vsby
reductions and gusty winds likely within the heavier pockets of
rainfall. Thunder looks most likely at KSME, where a locally
greater corridor of instability may emerge immediately ahead of
frontal passage. Once the front clears, southerly winds should
shift towards more of a westerly orientation and weaken/become
less gusty. The frontal passage should bring about an end to the
meaningful rain chances this evening, but low stratus clouds
are forecast to hang around overnight. Patchy fog also cannot be
ruled out given the wet grounds, and this combination of fog and
low stratus should keep MVFR to IFR conditions in place overnight
(especially at southern and eastern terminals). The low clouds
should gradually lift and scatter out tomorrow morning, with KIOB
likely the first TAF site to return to VFR conditions.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...JMW
AVIATION...MARCUS
Source:
JKL issues Area Forecast Discussion (AFD) at Nov 4, 4:01 PM EST---------------
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