Sassafras, Kentucky Weather Forecast Discussion

086
FXUS63 KJKL 301832
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
232 PM EDT Tue Sep 30 2025
.KEY MESSAGES...
- Increasing moisture around the outskirts of Tropical Storm
  Imelda`s circulation could produce a few rain showers in
  Southeastern Kentucky today.
- Dry and seasonably warm conditions return on Wednesday and then
  persist into early next week.
- Valley fog is likely to develop each night this week in the
  deeper river valleys of eastern Kentucky.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 232 PM EDT TUE SEP 30 2025
As of the 15Z surface analysis, the map is relatively quiet, with
the majority of significant activity centered around the two
offshore hurricanes. A dry cold front is currently oriented from the
mid-Atlantic westward to the northern Plains. Locally, conditions
are quiet as the forecast area is situated between surface high
pressure centered over northern Missouri and the aforementioned
tropical activity. However, high-level cirrus clouds associated with
the two hurricanes are streaming overhead.
Throughout the remainder of the day and extending through much of
the forecast period, the surface high-pressure system will shift
eastward and become the dominant synoptic feature, leading to
predominantly dry conditions. Despite this, sufficient upper-level
forcing and instability remain to support isolated showers and
thunderstorms this afternoon across portions of far southeastern
Kentucky. As the forcing mechanisms shift eastward and diurnal
heating wanes, these showers and storms are expected to dissipate,
leading to a quiet overnight period.
Maximum temperatures today and Wednesday are forecast to reach the
upper 70s to lower 80s. Upper-level northerly flow will advect drier
air into the region, resulting in lower dew points, which represents
the most significant deviation from the NBM throughout the forecast
window. With decreasing cloud cover expected later this evening,
clearing skies overnight will allow for effective radiational
cooling, increasing the potential for localized dense fog formation
within river valleys both tonight and tomorrow night. Overnight
minimum temperatures are expected to fall into the low to upper
50s.
.LONG TERM...(Wednesday night through Monday)
Issued at 515 AM EDT TUE SEP 30 2025
The main changes to the extended forecast this morning were to
enhance the terrain based differences for a ridge to valley
temperature split each night through next weekend. The PoPs are
still looking quite limited during the work week and into the
weekend.
The previous long term discussion follows:
The forecast guidance suite collectively resolves a mid/upper-level
ridge nudging into the Ohio River Valley on Wednesday as the
aforementioned upper level low and tropical cyclones eject further
east-northeast into the Atlantic. That ridging feature is then
forecast to strengthen, leading to mid-level height rises and the
development of a surface high pressure system over much of the
Eastern CONUS. The persistence of these two ridging features into
the weekend will keep skies mostly clear, foster efficient diurnal
warming/mixing processes, and allow temperatures to remain above
climatological norms through next Monday.
In sensible weather terms, expect seasonably pleasant conditions
throughout the period. Afternoon highs in the mid 70s to near 80 are
forecast each day, with ridge-valley splits likely to emerge at
night. While ridgetops will see lows in the upper 50s, the cooler
valleys will experience MinTs closer to 50. A few pockets of diurnal
minimums in the upper 40s cannot be ruled out, especially in the
more sheltered valleys of far-east Kentucky. Overnight river
valley fog has been added throughout the long term forecast period
given the synoptic pattern at hand, but the fog will likely
decrease in spatial coverage each night as the ground
progressively dries out. In fact, there are no mentionable PoPs in
the forecast from Wednesday through Monday. That dryness will
likely maintain or even worsen the D0/D1 drought conditions
currently delineated across most of the commonwealth.
There are some hints of moisture return from the Gulf just beyond
the end of the forecast period. However, models disagree on both the
timing and strength of its parent feature, leading to limited
extended-range precipitation forecast confidence. The CPC`s 6-10 and
8-14 day extended period outlooks mirror this sentiment; they show a
strong (60-80% chance) for above-normal temperatures, but no strong
signal towards wetness/dryness on the precipitation side. Autumn is
climatologically the dry season in KY, but surges of moisture
related to Gulf disturbances can interrupt this and dampen the
potential for fall fire weather concerns. Thus, the evolution of
that feature could become a focal point of future long term forecast
packages. With that being said, the main idea of today`s long term
forecast is the continuation of seasonably warm and dry conditions
into early October.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 124 PM EDT TUE SEP 30 2025
VFR conditions are expected throughout the TAF window. There`s
cloud cover associated with the tropical activity but as
mentioned, these CIGS will remain VFR. Clouds will decrease
overnight leading to increased river valley fog but fog should
remain out of the 5 main TAFs. Winds will remain light and
variable through the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...VORST
LONG TERM...MARCUS/GREIF
AVIATION...VORST

NWS JKL Office Area Forecast Discussion