Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

796
FXUS63 KJKL 300229
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1029 PM EDT Fri May 29 2026

.KEY MESSAGES...

- Showers and storms, some with torrential downpours leading to a
  risk of high water, are possible for areas generally along and
  south of a Harlan to London to Somerset line.

- Chances for showers and storms will return to areas mainly south
  of the Mtn Parkway for Sunday through Monday evening.

- Temperatures will average within a few degrees of normal over
  the next week.

&&

.UPDATE...
Issued at 1029 PM EDT FRI MAY 29 2026

Made some minor revisions to PoP/Sky and T/Td grids, the former
based on latest model and observed trends. Overall, there is no
substantive change to the forecast.

UPDATE Issued at 624 PM EDT FRI MAY 29 2026

Updated hourly T/Td grids for the next several hours. Hourly PoPs
and Sky grids were already sufficient, so made no changes for now,
but will reassess based on radar trends through the evening and
adjust accordingly. The forecast overall is in excellent shape, so
changes are minimal.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 415 PM EDT FRI MAY 29 2026

As of mid to late afternoon, an upper level low was centered east of
Nova Scotia with another upper low nearing the St Lawrence Valley
while the axis of an upper trough extended south east of the eastern
seaboard. Ahead of this upper low, a sfc wave was tracking into the
Northeast with a trailing cold front sagging into sections of the
Great Lakes. Meanwhile, a narrow upper level ridge extended from the
central Appalachians and eastern Ky to the western Great lakes.
Further south, a shortwave trough extended from parts of the MO
Valley to mid to Lower MS Valley and was nearing the Lower OH Valley
to TN Valley. At the surface, a frontal zone extended from GA into
the TN Valley to the Ozark vicinity to the Central Plains. A sfc
wave was moving along this boundary across AR and was nearing
western TN. Warm air advection/isentropic lift over this boundary is
resulting in convection over parts of middle TN to the TN Cumberland
Plateau south into parts of AL and GA. Some of this convection is
nearing Wayne and McCreary counties. Some low and mid level clouds
were currently over the southwest portions of the area while across
the remainder of the area more under the influence of the ridge just
passing high clouds were occurring.

Tonight and Saturday, the upper level low that is currently
approaching the St Lawrence Valley/Northeast is progged to move
across New England tonight and into the Atlantic on Saturday.
Meanwhile the shortwave that is nearing the Lower OH Valley should
meander east near the TN/KY border and into the Southern
Appalachians through Saturday morning. The narrow ridging should
remain in place across sections of the upper MS Valley/western Great
Lakes and then build back across the entire Commonwealth to end the
period. At the surface, a sfc wave will move along the initial
boundary into the southeast while the northern stream boundary drops
into eastern KY late tonight and across the remainder of the area on
Saturday morning. High pressure will then build in at the sfc to end
the period.

Insentropic lift/isentropic lift and the passing sfc wave to the
south should result in convection gradually spreading into the
southwest part of the area through the evening and into tonight,
before this activity diminishes on Saturday as the boundary drops
across the area. There is a small potential for convection near the
TN/KY border to move repeatedly over the same areas and lead to
localized heavy rain. Some CAM runs, including the 18Z HRRR have
some higher amounts across the eastern TN to eastern KY region as
high as 3 to 4 inches. Confidence in the location of this is not
high, as 12Z HREF max 6 hour amounts in excess of 2.5 to 3 inches
were mainly over parts of TN. Instances of high water or localized
flash flooding cannot be completely ruled out if training were to
occur in a location generally for areas along and south of a Harlan
to London to Somerset line.

Otherwise, convection will wave in southwest portions of the area on
Saturday morning with drier air working into eastern KY following
the cold front. This will set the stage for low temperatures to
trend colder, especially in the north and east with some upper 40s
to around 50 degree readings for the typically colder spots. With
the high building in, valley fog should also develop and more
southern/southwest locales could experience some dense fog following
anticipated rainfall over the next 18 hours.

.LONG TERM...(Sunday through Friday)
Issued at 400 PM EDT FRI MAY 29 2026

The period opens with an upper level low near Atlantic Canada,
another closed upper level low over the Mountain West, and
stubborn upper level ridging over central North America; in
essence, the start of the period will be characterized by an omega
block pattern, with eastern Kentucky east of the ridge. At the
surface, a high will be centered over the Great Lakes region, with
low pressure over the southern Great Plains and a wavy frontal
boundary extending across the southeastern US. On the other side
of the Appalachians, high pressure will dominate over the
southeastern Piedmont, placing eastern Kentucky in between these
elements. The forecast area will see increasingly southwesterly
winds on Sunday as the Piedmont high shifts eastward, and moisture
return is expected across much of eastern Kentucky, with the
highest dewpoints in the southwestern portion of our forecast
area. Meanwhile, the aforementioned boundary will lift northward
as a weak shortwave enters the Ohio Valley. This will bring
another round of rain to much of eastern Kentucky, with the
highest rain chances in the southwestern portion of the forecast
area. The big question with this pattern is the northward extent
of the boundary in addition to the positioning and amplitude of
the shortwave; for now, NBM PoPs were kept as-is to hedge for this
uncertainty, although with the caveat that current PoPs represent
a broad brushing of this active period. Overall, although
forecast details still remain somewhat fuzzy, rain will be likely
near the KY/TN line overnight on Sunday, with increasing
uncertainty further north.

Rain chances continue Monday as additional impulses rotate around
the trough under upper level northwest flow. The frontal boundary
will stall through Sunday night before it is again pushed back
south, with the highest rain chances on Monday remaining in the
southern portion of our forecast area. Meanwhile, the upper level
trough is expected to dig deeper into the northeastern US.
Concurrently, the upper level ridge axis previously centered over
the Plains will shift east as the block begins to break down. As a
result, at the surface, high pressure will begin to build in our
area. With northerly postfrontal winds ushering in drier air
(before diminishing overnight), rain chances will completely exit
the area by Tuesday morning, beginning a drier period.

Tuesday through Thursday, tranquil weather will return to eastern
Kentucky. With the northeastern low now over the Atlantic, upper
level troughing will be succeeded by ridging, and clear skies will
dominate. Highs will be seasonable (generally in the upper 70s to
low 80s), and northerly flow will keep dewpoints firmly in the
40s and 50s. This will create nearly perfect conditions for
outdoor activities each afternoon! In the overnight hours, dry
air will allow for below average low temperatures. Temperatures
will generally fall into the mid to low 50s across the area.
However, with high pressure over the area, there is a potential
for moderate ridge/valley temperature splits to develop each
night; thus, some sheltered valleys could fall into the mid to
upper 40s, and this is corroborated by MOS guidance (although dewpoints
bottoming out in the mid 40s will provide a reasonable floor for
temperatures in sheltered locations). Additionally, valley fog
will be possible in the mornings as temperatures approach
dewpoints in these areas. This generally pleasant pattern will
continue until our next chance for rain arrives Friday as ridging
breaks down and the overall upper level pattern becomes more
zonal.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 720 PM EDT FRI MAY 29 2026

A stationary front/boundary will sharpen from near Lake Cumberland
and KSME east-southeast to near KI35 (Harlan) by 03z and will
become the focal point for low clouds and shower and thunderstorm
activity through the overnight through late morning period.
PROB30, prevailing, and TEMPO groups were used to cover this
convective potential, but thunder chances were under 30 percent
and thus too low for a mention at this time. Drier air moves into
the area toward midday, forcing this stationary boundary south
into Tennessee as a cold front. Meanwhile, a secondary cold front
will move south into the area to end the period. Despite the cold
frontal passages, light winds are expected through tonight before
becomes northeasterly at less than 10 kts during the afternoon
hours Saturday.

&&

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

&&

$$

UPDATE...CMC
SHORT TERM...JP
LONG TERM...FAGAN
AVIATION...CMC