Jeff, Kentucky Weather Forecast Discussion

031
FXUS63 KJKL 051104
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
704 AM EDT Fri Sep 5 2025
.KEY MESSAGES...
- Another round of showers and thunderstorms is expected to impact
  the area mainly this evening into the overnight.
- A few of the storms this evening into the early overnight may be
  strong to severe; damaging wind will be the primary threat, but
  large hail and a brief spin-up tornado cannot be ruled out.
- Widespread rainfall totals between 1.0 to 1.75 inches are
  possible through late Saturday night, but locally higher totals
  are possible wherever stronger convection occurs.
- Below normal temperatures and drier weather will return this
  weekend.
&&
.UPDATE...
Issued at 704 AM EDT FRI SEP 5 2025
Just a quick update to account for the ongoing showers along the
KY-80/Hal Rogers Parkway corridor.
&&
.SHORT TERM...(Today through Saturday)
Issued at 510 AM EDT FRI SEP 5 2025
The latest surface analysis shows a weak stationary boundary
oriented northeast to southwest across the CWA. This boundary is
tied to an occluding surface low centered over the southern Hudson
Bay region. Another surface low and its associated cold front are
centered over Wisconsin and are tracking southeast toward the
Commonwealth. Locally, it is a mostly quiet night, though there are
areas of locally dense river valley fog and showers developing along
the stationary boundary.
Throughout the rest of the day, as the two systems Fujiwhara around
and upper-level closed circulation, the first front will lift out of
the region later this morning, leading to weak surface high
pressure. However, the second system will continue to track
southeastward toward the Commonwealth, placing the CWA in the warm
sector ahead of the second front in as many days. While in the warm
sector, southwesterly flow will allow temperatures to soar into the
upper 80s and low 90s this afternoon. As temperatures soar, the
stage is being set for potential severe thunderstorms later this
evening into the overnight. The southwesterly flow will usher in
more moisture, causing Tds to climb into the mid to upper 60s and
even into the low 70s ahead of a strong cold front. This increase in
moisture will cause instability values to increase significantly,
which is showing up in forecast soundings as SBCAPE and MUCAPE
values both exceed 2,200 J/kg later this afternoon. Along with this
abundance of moisture, bulk shear values will range from 40 to 50
knots ahead of the front. A third factor is that a good cap will be
in place this afternoon, allowing these ingredients to strengthen
for a longer period. Once that cap erodes, the potential for strong
to severe storms will be realized. The final factor that will play a
major role in this setup is the emergence of a LLJ at the time when
discrete supercells are forecast to develop. This combination will
be where the greatest hail and tornado threat will exist, but once
storms congeal and form a line, the damaging wind threat will
materialize and persist through the rest of the evening into the
overnight. Given this decent, yet conditional, threat, the SPC has
placed the area in a Day 2 Slight Risk, with a 15% wind risk, a 2%
tornado risk, and a 5% large hail risk. Coupled with the severe
weather threat, forecast precipitable water amounts of 1.70 to 1.90
inches, which is well above climatology, will also arrive via
southwesterly flow. These numbers, along with the expected stronger
storms, will combine to create heavy rain and possible instances of
hydrological issues across the entire CWA. Expected rainfall with
this frontal passage is between 0.75 and 1.25 inches, with locally
higher amounts possible.
Showers and thunderstorms will persist into Saturday as cold frontal
passage is forecast to be slow. However, by Saturday afternoon,
showers and storms will taper off from northwest to southeast, and
surface high pressure will build into the area for the remainder of
the forecast period. Temperatures on Saturday are expected to be 15
to 20 degrees colder due to upper-level west-to-northwesterly flow
and post-frontal CAA.
The period will be highlighted by the passage of a strong cold front
that will bring strong to severe storms this evening and tonight.
Surface high pressure will slowly build back into the region behind
the exiting front on Saturday afternoon. Temperatures will climb
into the mid to upper 80s and low 90s today but will be in the upper
60s to low 70s for Saturday. Tonight and Friday night will remain
mild, but cooler temperatures are forecast for Saturday night.
.LONG TERM...(Saturday night through Thursday)
Issued at 510 AM EDT FRI SEP 5 2025
Behind Saturdays cold front, a surface high-pressure system will
build into the region and will remain largely in place throughout
the long-term forecast period. Dry weather will accompany this
surface high pressure, and temperature swings will be the major
highlight in the forecast. Post-frontal CAA will continue to keep
cooler temperatures in the forecast through early next week, but as
flow begins to shift to a west-southwesterly direction, temperatures
will begin to climb back into more seasonal averages for the
remainder of the forecast period.
The period will be marked by the arrival of a surface high-pressure
system. Dry weather is to be expected. Temperatures will be slightly
below normal, with highs in the mid to upper 70s and overnight lows
in the upper 40s to mid-50s, before beginning to warm for the start
of the work week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 704 AM EDT FRI SEP 5 2025
TAFs are largely VFR minus KSYM which is experiencing low CIGS.
However, with diurnal warming, those CIGS will improve to VFR in
the next hour or two. A cold front will bring increasing shower
and thunderstorm chances later this afternoon which will persist
through the TAF window. Terminals will fall into a combination of
IFR to MVFR as these showers and storms move through the area.
Winds are forecast to be light and variable through the period but
convection will bring gusty and erratic winds.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...VORST
SHORT TERM...VORST
LONG TERM...VORST
AVIATION...VORST

NWS JKL Office Area Forecast Discussion