JKL issues Area Forecast Discussion (AFD) at Aug 30, 10:08 AM EDT843
FXUS63 KJKL 301408
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1008 AM EDT Sun Aug 30 2026
.KEY MESSAGES...
- Dry weather is expected through mid week, along with a distinct
warming trend. Heat indices will likely top 100 degrees in many
locations Wednesday and Thursday afternoon.
- Showers and thunderstorms will be possible, at times, from
Thursday into next weekend.
&&
.UPDATE...
Issued at 1008 AM EDT SUN AUG 30 2026
A couple of minor updates have been done this morning to blend
observations into the forecast, with little effect on the overall
forecast.
UPDATE Issued at 720 AM EDT SUN AUG 30 2026
No significant changes were made to the forecast with mainly just
the inclusion of the latest obs and trends for the T/Td/Sky grids.
These minor adjustments have been sent to the NDFD and web servers
along with a freshening of the zones.
&&
.SHORT TERM...(Today through Monday)
Issued at 425 AM EDT SUN AUG 30 2026
08Z sfc analysis shows high pressure located to the east of
Kentucky still in solid control of the weather over the central
Appalachians. Again this has meant light to calm winds, mostly
clear skies, and the development of river valley fog. In addition,
radiational cooling allowed a small ridge to valley temperature
difference to set up over the area with readings ranging from the
mid 60s in the low spots to the lower 70s on the hilltops.
Meanwhile, dewpoints are in generally in the mid 60s.
The models, and their individual ensemble suites, are again in
excellent agreement aloft through the short term portion of the
forecast. They all depict rising heights at 5h through Kentucky
as strong ridging from the southwest translates east into the
region through the weekend. As this heat dome approaches it shunts
the last vestiges of northwesterly mid-level flow off to the
northeast of Kentucky. This means subsidence will rule making for
benign but warming sensible weather. Again due to the very small
spread in the models' aloft, mainly unadjusted NBM data was used
for the forecast grids. However, some enhancements were made to
highlight terrain details in temperatures tonight along with
slightly lower afternoon dewpoints each day. Meanwhile, in
conjunction with the most current CAMs' consensus, PoPs were left
at near zero through the period.
Sensible weather will feature areas of valley fog, locally dense
near the rivers and lakes, clearing out shortly after sunrise and
not marring sunny skies for too long this morning. This leads to
warmer temperatures into the afternoon that pales in comparison to
what is to come for the middle of next week. Look for another near
repeat of night-time conditions tonight just with everything a
few degrees warmer and a similar valley fog setup. Monday looks
even warmer and continued dry as the warmer conditions aloft work
overhead while moisture also creeps higher. Through it all,
convection will be hindered by the subsidence of the ridging
overhead. Cannot completely rule out a stray shower or storm
popping up over the higher terrain but coverage and odds of being
hit by one of these even in the border counties will remain well
below 10 percent and thus unmentioned for forecast specifics.
The main adjustments to the NBM starting point were to once again
include specific terrain details in the upcoming overnight
temperatures. As for PoPs - kept them in the low single digits to
zero through the period thanks to sfc high pressure and building
heights aloft that dominating through the rest of the weekend and
start of the new work week.
.LONG TERM...(Monday night through Saturday)
Issued at 400 AM EDT SUN AUG 30 2026
The most current model data continues to endorse the current
forecast for a dry and steadily warming period into mid-week with
low to mid 90s on tap for highs at its peak as we get a bit
hotter each day. We still see the potential for convection in a
good number of the model solutions across forecast area on
Thursday and Friday - mainly in the afternoon and evening hours
owing to the 5h ridge weakening enough to allow northwest flow to
get close enough that any "ridge riders" can affect our area. Heat
headlines still may be needed for at least the western parts of
the area at midweek - still dependent on how effectively higher
dewpoints can move east into this part of the state.
The previous long term discussion follows:
Ridging remains the dominant synoptic weather feature at the start
of the long term forecast period, with the latest guidance
collectively resolving a 595 decameter ridge directly above the
commonwealth from Monday to Wednesday. Midlevel heights of this
magnitude rank above the 99th percentile of model climatology in the
blended LREF ensemble, and given that such values are the model
consensus, confidence is high that the Commonwealth of Kentucky will
experience hot and dry sensible weather conditions this week. The
ridging should eventually begin to break down by the end of the
period, but this is marked with a potential transition to more
active northwesterly flow. Ridge-riding disturbances allow chances
for showers and storms to reenter the forecast for Thursday, Friday,
and Saturday, but confidence in the forecast for wet weather at the
end of the period is lower than it is for hot weather at the
beginning.
Eastern Kentucky is positioned directly to the east of the mid/upper
level ridge axis. The related increase in subsidence aloft will
favor efficient diurnal processes for as long as the pattern
persists. Expect mostly sunny skies and increasing temperatures
accordingly, with ridge-valley temperature splits and river valley
fog emerging at night. Modeled 850mb temperatures climb above the
20 degree Celsius mark on Monday, remain elevated on Tuesday, and
then peak closer to 23 degrees Celsius on Wednesday. At the surface,
this should translate to widespread highs in the lower half of the
90s on Monday and Tuesday before some locations flirt with the upper
90s on Wednesday. The warmest temperatures will likely occur in the
northern half of the forecast area (where heights and 850mb temps
are the greatest) and in the deepest river valleys (where diurnal
mixing will be deepest). Blended NBM temperatures are likely too
warm, and dewpoints likely too moist. As drier air mixes down from
the midlevels, dewpoints will likely remain below the 70 degree
line. Heat indices may remain below the 105 degree heat headline
criteria mark, but it will still feel very hot outside. There won't
be much relief at night either, with ridge-valley splits above/below
the 70 degree mark. Interests with outdoor plans (such as high
school sports, recreational hikes, or camping) are encouraged to
review heat safety information at weather.gov/safety/heat in the
coming days. Take frequent breaks in the shade or indoors, stay
hydrated, and continue to monitor for forecast updates.
The northeastern periphery of the ridge begins to flatten on
Thursday, which will allow a NW flow regime to set up over the Ohio
River Valley. A series of shortwave impulses will then propagate
around the ridge and towards the forecast area headed into next
weekend, bringing about the next remarkable chances for showers and
storms. While 850mb temperatures will trend towards the 20C mark and
midlevel heights are progged to drop back down towards 590dm by
then, these disturbances will still be interacting with a seasonably
warm airmass. Models disagree on the amount of moisture available
during this pattern shift emerges, but if enough modified tropical
moisture makes it around the ridge and into the column, this late
period activity will need to be monitored closely. The available
machine learning, analog-based, and AI-enhanced long-range
convective guidance is hinting at more active weather in the Greater
Appalachians by the end of the period, but it is too early to
pinpoint specific timing and hazard details. With that being said,
the clouds and rain-cooled air associated with any convective
activity would likely mitigate the Major HeatRisk analyzed at the
beginning of the forecast period. Expect thermometer readings closer
to climatological norms for the holiday weekend, but monitor for
updates to the convective forecast while planning any outdoor
activities for Friday and beyond.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 745 AM EDT SUN AUG 30 2026
Sfc and upper level ridging will keep the terminals VFR for the
period along with light winds. The exception will be valley fog
resulting in MVFR to IFR or in some cases even worse through 14Z.
However, this is not expected to affect any of the TAF sites
either this morning or tonight.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...HAL/GREIF
SHORT TERM...GREIF
LONG TERM...MARCUS/GREIF
AVIATION...GREIF
Source:
JKL issues Area Forecast Discussion (AFD) at Aug 30, 10:08 AM EDT---------------
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