Delphia, Kentucky Weather Forecast Discussion

972
FXUS63 KJKL 191715
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
115 PM EDT Fri Sep 19 2025
.KEY MESSAGES...
- Mainly dry weather looks to persist through at least the first
  part of the weekend.
- Temperatures will continue to be above normal through this
  weekend and into next week.
&&
.UPDATE...
Issued at 1230 PM EDT FRI SEP 19 2025
The early afternoon update is out with no significant forecast changes.
UPDATE Issued at 720 AM EDT FRI SEP 19 2025
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 Saturday)
Issued at 430 AM EDT FRI SEP 19 2025
08Z sfc analysis shows high pressure still in control of the
weather over eastern Kentucky keeping winds light and skies mostly
clear. These conditions have led to another good night of
radiational cooling resulting in a moderate ridge to valley
temperature split along with river valley fog that has become
locally dense. Temperatures currently vary from the mid 50s in the
sheltered valley locations to the lower 60s on the hills.
Meanwhile, dewpoints are running in the mid to upper 50s, most
places.
The models, and their individual ensemble suites, continue to be
in excellent agreement aloft through the short term portion of
the forecast. They all depict weak ridging at 5h over Kentucky
this morning. This feature will slowly ease off to the east as
troughing nudges into the Ohio Valley from the Upper Midwest
tonight into Saturday. This approaching trough will urge a
distinct impulse to pass over eastern Kentucky that afternoon at
mid-levels. The still very small model spread for the next few
days continues to support the NBM as the starting point of the
forecast grids with minimal adjustments needed - mainly just to
include some terrain enhancements for temperatures tonight, but
also some details from the CAMs for PoPs on Saturday.
Sensible weather features another couple of warm and mostly dry
days with plenty of sunshine today, but more clouds on Saturday.
Expect a similar night compared to this one through Saturday
morning with a moderate ridge to valley temperature split and fog
found mainly to the river valleys. For Saturday, it looks like
there will be enough instability for some convection to percolate
nearer to the Tennessee border. Winds will be light through the
period, away from any Saturday storms.
The changes to the NBM starting point were primarily focused on
enhancing ridge to valley temperature differences tonight. As for
PoPs, they were kept in the low single digits to near zero today,
but allowed to reach the mid teens for Saturday given the better
support aloft and some signal in the CAMs and NAM for afternoon
convection over the Cumberland Valley.
.LONG TERM...(Saturday night through Thursday)
Issued at 455 AM EDT FRI SEP 19 2025
The main changes to the extended forecast on the overnight shift
were to tweak the temperatures each night to allow for a touch of
terrain based distinction into the first part of next week. The
chance PoPs each afternoon through the new week seem reasonable
and were left unadjusted.
The previous long term discussion follows:
Little change in the extended, with ridging building above the
eastern CONUS ahead of a developing trough in the central Plains.
Under increased upper-level heights, the warmest temperatures over
the next week come Saturday. Expect highs in the upper 80s to low
90s, and overnight low temperatures generally in the upper 50s to
low 60s. Temperatures gradually decrease by 1-2 degrees each day
Sunday through Tuesday, when the next disturbance looks to
encroach on the area.
As the wave in the Plains begins to develop, low-level flow will
become southerly and begin to advect moisture along the western side
of the Cumberland Mountains. Sunday features 10-20% PoPs in the
afternoon hours to reflect the potential for some low-coverage
afternoon pop-up showers, but confidence in occurrence as well as
specifics about timing and location is still too low to warrant
edits to NBM init.
Monday afternoon, PoPs in the 20-30% range reflect another chance of
lower-coverage afternoon showers that may gain some support in the
form of return flow from a mesohigh that gets stuck on the other
side of the Eastern Continental Divide. Rain chances do seem to
have stabilized some for Tuesday and Wednesday, with widespread
30-40% chances beginning Tuesday afternoon. The nature of shower
and storm chances Thursday and beyond will depend on the speed and
intensity of the shortwave when it arrives to our area, though
current guidance continues 25-40% PoPs on Thursday and Friday as
well.
Wednesday is when ensemble members go from well-aligned to
significantly divergent, with cluster analysis suggesting several
sources of uncertainty driving the disagreement, most of which can
be summarized as "what happens to the low once it bowls into
western Kentucky". Notably, while the EPS/GFS ensembles and EPS-
AIFS and GraphCast GFS machine learning ensembles do all have
differences between resolution of individual features and details,
all generally agree on a deepening upper low pushing towards the
eastern US by mid-week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 115 PM EDT FRI SEP 19 2025
VFR conditions will prevail along with light winds through the TAF
period, though valley fog will bring localized VLIFR conditions
to the river valleys beginning after ~03z and lasting until around
~13z, and as late as 14z in the Upper Cumberland Valley, before
burning off.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CMC
SHORT TERM...GREIF
LONG TERM...CAMDEN/GREIF
AVIATION...CMC

NWS JKL Office Area Forecast Discussion