662
FXUS63 KJKL 150545 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
145 AM EDT Tue Sep 15 2026

.KEY MESSAGES...

- Above normal temperatures return for today through Saturday.

- Near-record heat is possible Thursday with high temperatures
  within a few degrees of 90F.

- Isolated to scattered showers and storms re-enter the forecast
  on Thursday afternoon, then persist through the weekend. Most of
  that activity will be limited to the afternoon/evening hours.

&&

.UPDATE...
Issued at 125 AM EDT TUE SEP 15 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 SAFs and zones.

UPDATE Issued at 1031 PM EDT MON SEP 14 2026

The forecast is on track, with no significant changes needed.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 415 PM EDT MON SEP 14 2026

Current analysis shows a surface ridge passing over the Great
Lakes in the wake of a cold front that is stalled over the
Tennessee Valley/Southern Appalachians. Behind this front, cold,
dry air advection continues over Eastern KY. Satellite imagery
shows that the low cloud cover from this morning has thinned out
and been replaced by a few fair-weather cumulus and high, wispy
cirrus. Expect mostly clear conditions this evening and tonight
with temperatures dropping into the 50s for most areas. Fog
development is expected in the sheltered river valley areas given
efficient radiational cooling and dry air overhead.

Model guidance shows strong upper-level ridging building
over the Ohio Valley heading into mid-week. As this occurs,
low-level winds will turn more southerly on Tuesday,
advecting warmer air back across Eastern KY. By 18Z Tuesday,
the LREF supports impressive 500mb heights rising to near
climatological maxima for this time of year. With this
anomalous ridging, temperatures will peak in the upper 80s
and low 90s on Tuesday afternoon with dew points in the
60s. In spite of the heat, the moderate dew points should
keep heat indices below Heat Advisory criteria, although
areas west of I-75 could see values in the mid to upper 90s.
Fog remains possible in the valley locations again on
Tuesday night.

.LONG TERM...(Wednesday through Monday)
Issued at 530 PM EDT Mon Sep 14 2026

Ridging remains the dominant synoptic-scale weather feature across
the Eastern Kentucky for the duration of the long term forecast
period. When the period opens on Wednesday morning, a nearly 600
decameter ridge will be centered over the Tennessee River Valley, or
just to the south of the forecast area. The strength of this ridge
is quite impressive. These modeled geopotential heights rank among
the upper echelon of model climatology for this time of year. In
fact, mean LREF heights of 600 dm sit at the 100th percentile of
the dataset. This signal has been present in the data for multiple
runs in a row, which bolsters forecast confidence. The proximity
of this anomalously strong mid/upper atmospheric ridging should
accordingly yield mostly dry and unseasonably warm sensible
weather conditions across Eastern Kentucky. On Wednesday, expect
high temperatures in the lower 90s, mostly sunny skies, efficient
diurnal mixing processes, and overnight ridge-valley temperature
splits. Valley lows in the mid/upper 60s should be sufficient for
patchy fog formation near sources of water, while ridgetops and
the more exposed western locales could stay closer to the 70
degree mark.

Confidence in these dry/hot conditions is highest on Wednesday, as
the parent ridging will be closest to the JKL CWA in this time
frame. Large-scale subsidence and antecedent dry air throughout the
column will largely limit the potential for meaningful convection in
the initial stages of the period. The dry air (and mixed afternoon
dewpoints) should also prevent Eastern Kentucky from reaching heat
advisory criteria. Apparent temperatures peak in the upper 90s, but
remain largely below the triple digit mark. The heat continues into
Thursday, with similar forecast highs in the lower 90s and heat
indices in the upper 90s. While this may be enough to break the
record high at the Jackson climate site, this is only because the
previous record is a "weak" 90 degrees. The pattern actually looks
to shift a little bit on Thursday, and that shift will eventually
culminate in relief from the heat.

As the ridge retrogrades west a little bit, return flow around its
northern periphery will advect a plume of modified Gulf moisture
towards the CWA on Thursday. The presence of this moisture will
likely make it feel a couple of degrees warmer outside in the
western third of the CWA. Those western counties will remain closer
to the center of the ridge and thus under more of its influence.
Locales situated in the Bluegrass and near Lake Cumberland could
flirt with triple digit heat indices on Thursday, but this is
unlikely in counties further to the east. Isolated to scattered
general thunderstorm chances re-enter the forecast on Thursday
afternoon for locations along and east of the Pottsville Escarpment.
Similar, sub-50% PoPs remain in the grids through the weekend,
largely modulated by the diurnal instability cycle. These could
provide some localized pockets of relief from the heat before a more
robust pattern shift emerges early next week. The forecast guidance
suite continues to disagree on how exactly that pattern change
unfolds, but there is a notable increase in the spread between the
25th and 75th NBM temperature quartiles on Sunday and Monday. This
affirms the notion that the increased rain chances correspond with
increased forecast uncertainty surrounding the heat in the latter
stages of the period. However, there is a better-defined downward
trend in the temperatures early next week, with more compact model
spread and median values back in the upper 70s/near 80 degrees.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 145 AM EDT TUE SEP 15 2026

VFR conditions are expected at the terminals with light and
variable winds through the rest of the night. Fog is developing
in the typical river valley locations. Daytime cumulus development
will be suppressed at most locations due to the presence of dry
air and strong mid-level ridging, but will be more prevalent along
and south of the KY-80 corridor, mainly impacting LOZ and SME.
Southwest winds at 5 kts or less can be anticipated from late
morning through the afternoon.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...GREIF
SHORT TERM...GEERTSON/HORTON
LONG TERM...MARCUS
AVIATION...CMC/GREIF