Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

489
FXUS63 KJKL 191648
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1248 PM EDT Fri Jun 19 2026

.KEY MESSAGES...

- High pressure has brought dry weather that lasts to near the
  end of the weekend.

- An increased risk for excessive rainfall and resulting flash
  flooding returns late Sunday and then persists through late
  Monday night or early Tuesday morning. Forecasts will evolve
  over the next couple of days, so check back for updates.

&&

.UPDATE...
Issued at 953 AM EDT FRI JUN 19 2026

A cu field from residual low level moisture is undergoing a small
bloom this morning as diurnal heating gets underway. As heating
continues, a mix down of drier air should eventually thin out the
clouds. Overall, all forecast changes are very minor.

&&

.SHORT TERM...(Today through Saturday)
Issued at 312 AM EDT FRI JUN 19 2026

An upper-level trough axis shifts from over the Ohio River Valley
to the Mid-Atlantic region today, and then largely remains in
place through Saturday afternoon. An unusually active jet stream
will remain over the Ohio River Valley and Mid-Atlantic through
this time.

Relatively cool and dry conditions for mid-June can be expected
through Saturday, with west-northwest to northwest near-surface
and upper-level flow through the period. Highs for today are
expected to reach the mid 70s to lower 80s, with temperatures
warming about five degrees for Saturday from today with highs in
the lower to mid 80s. Lows tonight will likely fall into the mid
to upper 50s, and widespread valley fog can be expected given the
recent wet conditions and surface high pressure building over the
region, especially south of Interstate 64.

.LONG TERM...(Saturday through Thursday)
Issued at 627 PM EDT THU JUN 18 2026

The long term period will open with broad 500 mb troughing over
the Northeastern CONUS and Midwest, with ridging over the Mountain
West and High Plains. Farther west, a secondary, more compact
trough will be located over the Pacific Coast. At the surface,
high pressure will persist over Kentucky, and pleasant weather is
expected throughout the day on Saturday. Highs will remain
relatively mild (in the upper 70s to low 80s in most of the
forecast area), and winds are expected to remain light, with good
model consensus regarding a weak pressure gradient over our area.
Some model discrepancy still exists regarding the exact location
of this surface high during the day on Saturday, owing to
differences in the eastward progression of this feature. This
positioning will have implications on the magnitude of moisture
return; a quicker eastward translation of this high would allow
for enhanced moisture advection via southwesterly winds on
Saturday, whereas a slower surface high would delay this moisture
return. Regardless, skies should remain mostly clear on Saturday
night into early Sunday morning, and with high pressure overhead,
a modest ridge-valley temperature split is expected, with the
floor for low temperatures remaining dependent on dewpoints going
into Saturday night. MOS guidance suggests that low temperatures
could fall into the mid 50s in our sheltered hollows, but given
uncertainty regarding dewpoints going into the overnight hours,
these hollows were generally kept in the upper 50s for now, with
ridges seeing minTs in the low to mid 60s. This will also allow
for typical fog formation overnight in mainstem river valleys.

On Sunday, a shortwave rotating around the base of the broad
eastern CONUS trough will travel across the Plains, taking on a
negative tilt as it approaches the Ohio Valley by Sunday evening.
Meanwhile, the associated surface low will translate northeastward
into the Midwest, and a warm front extending from this low is
expected to lift northward into our area on Sunday as high
pressure fully exits our area. Accordingly, rain chances are
expected to return as early as Sunday afternoon. Instability will
be modest Sunday evening (with mean ensemble CAPE well below 1000
J/kg across the forecast area), but will be adequate for some
thunderstorms in our area. More notably, rich moisture is expected
to be in place late Sunday into Monday, with anomalously high
PWATs likely; LREF guidance shows mean PW values ranging from 1.7
to 1.9 inches across eastern Kentucky, indicating column moisture
generally in the 95th percentile or higher compared to
climatology. Accordingly, WPC has placed eastern Kentucky in a Day
4 and Day 5 Marginal Risk for Excessive Rainfall (Level 1/4),
indicating an environment conducive to flash flooding on both
Sunday and Monday. However, great uncertainty still remains with
this pattern.

Rain chances will continue through at least Monday, although
guidance diverges significantly at this point. Generally, multiple
shortwaves could impact the area, leading to repeated shower and
storm chances through at least Monday; after this, uncertainty
compounds. At the surface, the original low is expected to
generally continue to translate eastward along with an associated
cold front, although there is presently low confidence regarding
the progression of this front. Some models (such as the GFS) hint
that the front may stall near our area, bringing repeated rounds
of rain and storms to the Commonwealth. In this scenario, the
flooding risk would increase, particularly given such rich
preexisting moisture. Alternatively, other models (such as the
ECMWF) favor a relatively progressive system, with the cold front
clearing our area Monday night. With this discrepancy in mind, the
spread for instability is quite large on Monday
afternoon/evening; in a more progressive scenario, a combination
of frontal forcing and relatively higher instability could allow
for a low end risk for severe weather, with some machine learning
guidance hinting at this possibility. However, uncertainty remains
very high with this setup. Looking beyond Monday, confidence
remains low as sensible weather impacts will remain dependent on
the progression of embedded shortwaves within general troughing.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1248 PM EDT FRI JUN 19 2026

Valley fog is expected to develop late tonight and grow in breadth
and depth until it dissipates after sunrise. It will bring
localized IFR or worse conditions, and may affect KSME and KLOZ
at times. Otherwise, VFR conditions are forecast.

&&

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

&&

$$

UPDATE...HAL
SHORT TERM...CMC
LONG TERM...GEERTSON
AVIATION...HAL