Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

597
FXUS63 KJKL 181252
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
852 AM EDT Thu Jun 18 2026

.KEY MESSAGES...

- Increasing winds just above the surface are expected early this
  morning. Gusts outside of storms of 30 to 40 mph are possible
  and could be stronger near and north of I-64.

- Storm chances return through tonight. Some storms could be
  severe this morning as far south as locations near the Mtn Pkwy,
  and mainly south of the Mtn Pwky this afternoon and evening.

- The primary threat from storms today will be damaging wind
  gusts. Isolated to scattered flash flooding is also possible in
  locations that receive repeated rounds of heavy rainfall.

&&

.UPDATE...
Issued at 850 AM EDT THU JUN 18 2026

Given recent CAM trends and trends with convection including
upstream of the area, and some areas northwest of JKL along the
Mtn Parkway corridor having picked up 2 inches of rain so far, opted
to hoist a flash flood watch through 06Z Friday (3 AM EDT). The
threat in the north appears to be waning as the outflow boundary
is getting hung over the middle of the CWA.

UPDATE Issued at 525 AM EDT THU JUN 18 2026

Tornado watch 349 has been issued through 11 AM EDT for northern
and eastern sections of the CWA for the reasoning below. This line
should continue to affect areas generally north of the Mtn Pkwy
over the next few hours and upstream training way continue east
near the I-64 corridor during that time and concerns could shift
to heavy rain and excessive rain.

&&

.SHORT TERM...(Today through Friday)
Issued at 415 AM EDT THU JUN 18 2026

Early this morning, broad troughing remains from central and
eastern Canada south into the central and eastern Conus from an
upper level low near the Ontario and Manitoba border to the south
of Hudson Bay. A shortwave trough was rotating around a weak upper
low over the Lake Superior area with this shortwave trough
extending from the central Great Lakes to the Lower OH Valley area
and there are additional shortwaves rotating from parts of Canada
into the Northern Plains/upper midwest into the troughing while an
upper low/remnants of Arthur were near the MS delta vicinity. At
the surface, an area of low pressure was tracking across MI with a
warm front southeast into the central Appalachians and a cold
front trailing into the mid MS Valley to Southern Plains. An
outflow boundary ahead of this front was in the vicinity of the OH
River from the OH/KY border westward. Some strong to severe
convection was ongoing in its vicinity with training convection
in southern OH leading to heavy rain and instances of flooding and
a line of strong to severe storms from sections of northern KY to
just north of Louisville to southern IN and IL. A warm and rather
moist airmass is in place ahead of the cold front and of most
interest the outflow boundary interacting with the passing
shortwave. Recent mesoanalysis has SBCAPE of 500 to 2000 J/kg
form the western portions of the CWA into central Ky near and to
the west of the I-75 corridor. Some inhibition/CIN does linger
over far northern, northeastern, and southeastern KY. Sfc
temperatures are abnormally warm for this time of year mainly in
the mid 70s to around 80. dewpoints were in the mid 60s southeast
to around 70 or the lower 70s over northeastern near and
northwest of I-64 to northern KY and across central and western
KY. MLCAPE values were a few hundred J/kg lower with some CIN
though relatively weak over northern KY with higher values of
inhibition over the east. Effective shear is currently analyzed
with a min of 30 to 35 KT near the US 23 corridor and WV border
area and then west near the KY and VA border and KY and TN border
with values further north and west in the 35 to 55KT range or
more than sufficient for the organized convection as noted
upstream with marginal to moderate instability values. Also of
note, is effective SRH values of 200 to 500 across the region with
the highest values near and just ahead of the upstream line.
Sections of this line have been able to be more
normal/perpendicular to the 0-3km shear vectors and favorable for
embedded QLCS type tornados at times.

Through this morning, the upper low over the Great Lakes will
meander into Ontario to the north of Lake Huron while the upper
low in Canada meanders near the Manitoba and Ontario border with
the broad troughing remaining place from the central and eastern
Conus. Meanwhile, the shortwave trough rotating around the Great
Lakes upper low tracks into Ontario, the eastern Great Lakes, and
lower to middle OH Valley and then to the Northeast to mid
Atlantic and well east of eastern KY by late morning/midday.
Meanwhile, the remnants of Arthur/upper level low will move into
the southeast eventually opening up as it nears the southern
Appalachians. At the same time, very little change will occur in
500 mb heights across eastern KY from late morning through early
this evening. Meanwhile, the sfc outflow boundary will drop into
eastern Ky and may stall while the sfc low tracking across the
Great Lakes to portions of Ontario and Quebec through early this
evening sags gradually toward the area. One of the weaker
shortwaves moving through the trough may near later today/this
evening potentially leading to a sfc wave hanging up/leading to
slow movement of the boundary with Arthur remnants also playing a
role. However, this next shortwave trough axis will move across
eastern KY tonight with Aurthur`s remnants moving into the
Carolinas. Behind that shortwave trough axis, colder and
especially drier air will move into the Lower OH Valley as the
broad troughing pattern remains from the central to eastern Conus.

As for the mesoscale environment through around 12Z to 14Z,
MLCAPE is expected to reach 1000 to 1750 J/kg ahead of the outflow
boundary with CIN going away with again, SBCAPE values may be
about 250 J/kg as sfc dewpoints around 70 or the lower 70s become
widespread. PW will also climb from current values in the 1.4 to
1.6 inch range to about 1.7 to 2.0+ inches per recent RAP runs
ahead of the outflow boundary or the 90th percentile to 97th
percentile range. Until the shortwave trough moves east a couple
of hours after sunrise, the LLJ of 40 to 60KT will be across the
region, before these values drop 30 to 40KT by midday. Thus the
best effective shear of near 30KT south and 40 to 60KT north will
be present over the next 3 to 6 hours with 250 to 400 m2/s2
effective SRH during that time before these values decrease to
about 25 to 35KT effective shear and 200 m2/s2 for effective SRH.
Wind gusts to severe limits have been observed upstream and some
CAM runs including some recent HRRR runs have some strong to
severe limits wind gusts reaching the north and if a cell were to
align with the shear a QLCS tornado cannot be ruled out over the
next couple of hours mainly near or north of I-64 as the QLCS
reaches eastern KY prior to dawn.

However, the outflow boundary may hang up somewhere south of I-64
per recent CAM runs by which point training of cells becomes a
concern. In addition, even with the weaker shear during the midday
to evening period, 1500 to 2000 J/kg MLCAPE with 7 to 8C/km low
level lapse rates a few instances of strong to damaging wind
gusts would be supported and some CAM runs have sporadic wind
gusts to 40KT or above in the south. Thus the severe threat will
linger as does the heavy to excessive rain threat. Most of eastern
KY remains in both a Slight Risk of Severe Thunderstorms today
and a Slight Risk for Excessive Rainfall. Again, by late evening
or the overnight, this threat should wane for all areas.

Drier weather follows for late tonight and Friday with sfc high
pressure noses into the OH Valley with highs likely to fall
around 5 degrees below normal.

.LONG TERM...(Friday night through Wednesday)
Issued at 300 AM EDT THU JUN 18 2026

The long-term period opens Friday evening with lingering broad 500
hPa troughing over the Great Lakes and Northeast CONUS while a
similarly broad upper-level ridge extends from Mexico northward along
the Rockies. Embedded shortwave energy is passing through the broad
troughing while another Pacific trough is noted along the West Coast.
At the surface, high pressure will be centered over the Lower Ohio
Valley.

This will set the stage for a quiescent and pleasantly cool start to
the weekend on Friday night with efficient radiative cooling under
mostly clear skies and light winds. Temperatures ranging in the 50s
are expected to be widespread late in the night, and given recent
rainfall, fog formation will be likely through many of the typically
favored valley locations. Heights will then rebound weakly on
Saturday as high pressure transits eastward. It will be quite
delightful with highs in the lower to mid 80s under mostly sunny
skies.

Meanwhile, the West Coast shortwave trough energy will pass through and
flatten the western ridge and eventually transit the Ohio Valley late
Sunday into Monday. This will support an area of low pressure
tracking from the Central Plains early Sunday morning to north of the
Ohio River on Sunday evening and off the New England coast Monday
evening and night. This system will lift a warm front across the
Coalfields on Sunday, bringing rain chances back to the forecast and
persisting into Monday before diminishing with the passage of the
systems trailing cold front. Some locally heavy rainfall is possible
during this time frame with elevated PWATs, though the system appears
progressive overall. WPC has Day 4 and 5 Marginal Excessive
Rainfall Outlooks (EROs) for eastern KY as well as sections of
the OH Valley and Appalachians for the heavy rain potential with
this following a few days after anticipated rainfall in the short
term period. Another area of high pressure will pass across the
Great Lakes for Tuesday and Wednesday with the return of cooler
and drier weather.

Forecast daily high temperatures reach the warmest of the period on
Sunday, ranging in the mid 80s for most locations before dropping back into the
70s to around 80F from Monday through Wednesday. Meanwhile, nighttime
lows range from 55 to 65F, except on Sunday night when forecast lows
are 65 to 70F.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 755 AM EDT THU JUN 18 2026

Generally VFR conditions are currently in place south of KJKL and
KSJS with gusts head of convection upwards of 25KT. At this time,
a line of thunderstorms and sagging outflow boundary extends from
just south of KSJS to KJKL. Within the convection, MVFR to IFR
ceilings and vis are anticipated. Convection should continue
between a line from KIOB to KSYM and to just south of KJKL and
KSJS to begin the period, but may take a few hours to reach KLOZ
and KSME. A generalized uptick in intensity with coverage
reaching the more southern areas such as KLOZ and KSME may occur
during the 16Z to 00Z timeframe. MVFR to IFR conditions driven by
visibility reductions and lowered ceilings may become prevailing
for a time at that point for some locations, with further
reductions briefly possible at terminals impacted by
thunderstorms. Wind gusts of 30 to 40KT or stronger will be
possible in the stronger cells from near KJKL to KSJS south.
Shower and storm chances will wane from northwest to southeast
between 00Z and 09Z as a cold front drops south of the area. A
continuation or prevailing MVFR and IFR may develop in the south
late in the period per recent guidance.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 AM EDT this morning for KYZ044-050>052.

Flood Watch through late tonight for KYZ058>060-068-069-079-080-
083>088-104-106>120.

&&

$$

UPDATE...JP
SHORT TERM...JP
LONG TERM...GEERTSON
AVIATION...JP