Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

619
FXUS63 KJKL 161748
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
148 PM EDT Tue Jun 16 2026

.KEY MESSAGES...

- Cooler than normal temperatures will continue for highs today,
  which will average about 5 degrees below normal.

- Storm chances return for the latter portion of the work week
  (Wed night-Fri). Some storms could approach severe limits,
  especially on Thursday.

- The primary threat will be damaging wind gusts. Isolated flash
  flooding is also possible should locations see repeated rounds
  of heavy rainfall.

&&

.UPDATE...
Issued at 1055 AM EDT TUE JUN 16 2026

Populated the latest observational data from around the region
and tweaking some temperature curves through this afternoon.
No major changes were made to the forecast for today and tonight.
The wind and wind gust forecast grids Wednesday evening and
overnight were adjusted up using a blend of the CONSShort and the
NBM.

UPDATE Issued at 737 AM EDT TUE JUN 16 2026

Hourly grids were freshened up based on recent trends in observations.
No changes were made to weather grids for fog. Where breaks in
the clouds are present, valley fog remains evident. This should
lift and dissipate through around 9 AM EDT and give way to mostly
sunny to sunny skies with temperatures trending warmer.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 535 AM EDT TUE JUN 16 2026

Early this morning a broad upper trough extended from central
portions of Canada into portions of the central Conus/MS Valley
into the Great Lakes and eastern Conus. An upper low/shortwave
trough moving through the trough and rotating around an upper low
in Canada centered just west of Hudson Bay was tracking across
sections of the upper MS Valley to mid MS Valley. At the surface,
departing sfc high pressure was centered over the Central
Appalachians/WV while a sfc low associated with the upper MS
Valley shortwave was also moving across the western Great
Lakes/upper MS Valley area. The trailing cold front extended
southwest into the Central Plains while a warm front extended into
the Lower OH Valley near the confluence of the MS and OH Rivers.
Locally a few areas of mid and high clouds were crossing southern
portions of eastern KY while there were areas of low to mid level
cloud cover over OH, WV, KY, and IN with these currently more
focused over northeastern KY and near and west of the Louisville
vicinity. Particularly where there were breaks in the clouds,
valley fog had formed near the larger creeks, rivers, and lakes
with reductions below one mile in some cases. Temperatures ranged
in the upper 40s to lower 50s in valleys to the mid to upper 50s
on the coalfield ridges and in areas of more open terrain.

Today and tonight, broad troughing will remain in place across
sections of the Central to eastern Conus with the upper
low/associated shortwave trough currently over the upper MS Valley
and nearing the western Great Lakes becomes more of an open
shortwave as it rotates across the Great Lakes portions of the OH
Valley to the Ontario and the mid Atlantic. Additional shortwaves
will rotate around the meandering upper low west/southwest of
Hudson and James Bay with the first of these crossing the
Dakotas/northern Plains and nearing the upper MS Valley toward
dawn on Wednesday. An additional shortwave or two will also move
to near the US/Canadian border in the ND to MT vicinity. As this
occurs, the previously mentioned sfc low is expected to track
across the western and central Great Lakes and into Ontario while
the trailing cold front nears the Lower OH Valley. The associated
warm front lifts across the OH Valley today with eastern KY in the
warm sector by later today and tonight.

For Wednesday, the next shortwave will near the western Great
Lakes and extend into the mid MS Valley and near the Lower OH
Valley Wednesday evening. Another sfc low/sfc low pressure system
further west along the frontal/baroclinic zone and associated
with this next shortwave should become centered from the E SD/SW
MN/W IA/E NE area by early on Wednesday. As this sfc low nears the
western Great Lakes and the shortwave nears the Great Lakes, the
portion of the frontal zone in the OH Valley should lift back
north as a warm front.

Temperatures will moderate a bit today compared to Monday with
highs expected to fall about 5 degrees below normals for mid June.
Fair weather cumulus are again expected to develop though some
convection near the approaching frontal zone should near areas
near or northwest of I-64 toward sunset/late evening. Shower
activity will remain possible particularly nearer to this
boundary and a couple of stray showers or sprinkles could occur
south of the current area of pops which are near and northwest of
I-64 with the shortwave trough crossing eastern KY as per 06Z
HRRR. Otherwise, with winds remaining rather light and mainly high
and at times mid level clouds, valley fog should form over the
southern half to two thirds of the area further away from the
frontal zone that will slow down/stall near the OH River. The
rather strong sfc low approaches WI/IL with eastern KY well into
the warm sector on Wednesday. Southwest flow will bring
temperatures back to a bit above normal levels for highs. Mixing
may only lead to a modest increase in sfc dewpoints. PW only
gradually increases from current levels near the 10th percentile
to about the 50th or 60th percentile, 1.1 to 1.4 inch range, per
the 00Z HREF mean. Otherwise, extensive convection is expected to
develop over sections of the midwest by Wednesday afternoon and
evening and as this evolves east and southeast could approach
eastern KY early in the long term period when moisture increasing
significantly.

.LONG TERM...(Wednesday night through Monday)
Issued at 400 AM EDT TUE JUN 16 2026

Active weather remains the central theme of the long term forecast
period, with the period opening on the precipice of the well-
advertised Wednesday night into Thursday storm system. However,
compounding forecast uncertainty looms large over this setup, which
will likely be governed by mesoscale features that models struggle
to resolve this far out. Adjustments to the SPC and WPC outlooks for
severe storms and excessive rainfall are likely as these finer scale
details are worked out, but there remains a synoptic signal for
potentially impactful weather in the second half of the work week.

An anomalously strong 850mb jet streak is poised to develop over the
warm sector of a deepening surface low on Wednesday night. The
tightening surface pressure gradient will allow southwesterly winds
to strengthen to 10-20mph, with non-thunderstorm gusts potentially
as high as 35mph. Models collectively resolve 45-65 knots of
southwesterly flow at that 850mb level, and together, this sets up
an efficient warm air advection and moisture return conveyor belt.
These processes look to impede the traditional overnight radiational
cooling processes and thus prevent our area from experiencing the
conventional overnight ridge-valley temperature splits. Sheltered
southeastern valleys and hollows could still cool off into the upper
60s after sunset, but the strengthening wind fields will likely keep
most of the CWA mixed at night. Expect widespread MinTs in the lower
half of the 70s. This would place the record maximum lows at the
KJKL (72) and KLOZ (71) in jeopardy, and these unseasonably warm
overnight temperatures give credence to the notion that the
atmosphere may remain unstable enough for strong to severe storms on
Thursday morning.

The initially semi-discrete convection on Wednesday night is progged
to congeal into a QLCS moving south-southeast towards the
commonwealth overnight. By dawn, the evolving line of storms should
be on the doorstep of the I-64 corridor. This means that the initial
phases of the event have entered the window of time that gets
resolved by the higher-resolution, convection-allowing models. As of
the time of writing, a few of these CAMs (the NAM and the
experimental RRFS) resolve 850-1250 J/kg of surface-based CAPE in
the Bluegrass region for the 6am-8am time frame. These marginally-
favorable thermodynamics could combine with the anomolously-strong
kinematics to present a HSLC-esque environment (High Shear, Low
CAPE) for this first round of storms. There are 40-50 knots of shear
and steeply curved/hooked hodographs in forecast model soundings
ahead of the line, which suggests that if the line stays organized,
both damaging wind gusts and isolated QLCS tornadoes would be
possible. However, it is crucial to note that some guidance also
resolves the line falling apart as it approaches our forecast area.
By the time it reaches Fleming County, the line of storms will have
outrun the parent frontal boundary and become displaces from the NE-
propagating surface low. Thus, it could lose its synoptic forcing
and weaken in an environment with improper CAPE/shear balance. If
the line develops enough of a mesoscale cold pool and is
subsequently able to create its own localized forcing mechanism, it
could sustain itself within a volatile environment. SPC has
accordingly outlined counties along/NW of the Mountain Parkway in a
Marginal (Level 1/5) Risk on Thursday morning. We will need to
closely watch radar as storms enter our CWA, but in the meantime, we
will be laser focused on trends across the hi-res guidance suite. We
encourage readers to make sure that they have multiple ways to
receive weather updates and warnings ahead of time. It also might be
a good idea to take advantage of the pleasant weather leading into
the event to secure any loose outdoor objects, as both the breezy
non-thunderstorm wind gusts and any convectively-enhanced wind gusts
would be strong enough to cause at least nuisance-level impacts.

The evolution of that AM activity will prove crucial to the forecast
for the rest of the day. It is plausible for a remnant outflow or
differential heating boundary to create a locally-favorable
convergence corridor for additional convection on Thursday
afternoon/evening. The mid/upper level synoptic features responsible
for the strong wind shear parameters will steadily lift off to the
northeast as the day progresses, with the trailing cold front
steadily sagging south into Kentucky. There should be enough frontal
forcing for showers and storms to develop, but the magnitude of the
warmth and the depth of the moisture ahead of the boundary remain
uncertain. Leftover cloud debris from any AM convection could
inhibit the diurnal heating curve and cause temperatures/instability
to under-perform current expectations. A developing low pressure
system over the western Gulf introduces further forecast
uncertainty, as models are clustered around two groups of tracks
with it. The slower/western cluster would funnel a plume of modified
tropical moisture into the region out ahead of the slowing boundary,
whereas the faster/eastern solution could keep the richest/deepest
tropical moisture confined to the south in the Tennessee Valley.
Models should begin to come to a consensus regarding this system as
the Hurricane Hunters begin to sample its core in the coming days
and provide better initialization conditions. At the very least, a
modified continental tropical airmass will be in place, and as of
the time of writing, the LREF ensemble resolves a mean 1.5 to 1.75
inches of PWAT across the CWA. Areas closer to I-64 are closer to
the synoptic boundary and on the lower side of this range, whereas
areas along the TN state line are on the higher side.

The synoptics of the setup still suggest at least a Marginal Risk
(1/5) for strong/severe storms on Thursday afternoon/night. This
portion of the forecast period remains outside the temporal range of
the hi-res CAMs, but medium-range guidance still portrays those
aforementioned PWAT values, 30-50 knots of zonal flow aloft,
marginal amounts of CAPE, and high freezing levels. Barring any
mesoscale boundary enhancements, there should be less
directional/speed shear during the PM hours than there was on
Thursday morning. Still, damaging straight-line wind gusts could
emerge within any organized storm clusters or water-loaded
downdrafts in the warm sector on Thursday afternoon/evening. SPC has
drawn an extensive slight risk outlook, but notes that potential
is more for isolated line segments with a wind threat.

There is also an area-wide Slight (2/4) Risk for Excessive Rainfall
on Thursday and Thursday night. The parent cold front will likely
stall out and adopt a quasi-zonal WSW/ESE orientation in this time
frame. Such an orientation parallels the flow aloft and points
towards potentially training convection. That training behavior will
be the root of any localized hydro issues that develop through
Friday morning, which WPC notes is most likely to set up in Southern
Kentucky. Training storms are not necessarily accounted for in the
current QPF grids though. The model blend used to populate the long
term forecast grids does not explicitly account for convective
processes like training, so the QPF grids have stagnated in the 1-
1.5 inch range after the previous day`s downward trend. Expect
further adjustments to these forecast rainfall amounts as the event
approaches and convection-allowing guidance becomes incorporated. It
is plausible for some embedded streaks of higher QPF values to
emerge in future forecast packages, especially within any favored
mesoscale corridors for convergence and/or training that emerge.

There are a few limiting factors that could mitigate the flood risk
in Eastern Kentucky with this event. Antecedent drought conditions
and lackluster accumulations from the past few rain events have kept
Flash Flood guidance on the higher end of things, with 1 hour
guidance in the 1.75 to 2.5 inch range and 3 hour guidance between
2.5 and 4 inches. Area hydrographs are running below normal flow
values, so the rain from this system should initially prove
beneficial. Widespread flooding on the mainstem rivers appears
highly unlikely, but more localized flash flooding and/or nuisance
pluvial flooding cannot be ruled out if stronger convection trains
over the same few locales. The risk for flooding is highest in
places that see multiple rounds of activity by the time the front
finally starts to push south on Friday morning. WPC maintains a
Marginal ERO for SE KY on Friday, but that is largely an artifact of
Thursday`s activity persisting past the 12z outlook transition time.
WPC also notes that additional adjustments may be needed to the
Slight portion of Friday`s outlook, which is currently just across
the state line in SW VA/NE TN. Those adjustments will depend upon
the evolution of the tropical system and its related moisture plume,
which further demonstrates how this particular long term forecast
package is shrouded in compounding uncertainty.

Current expectations are for precipitation to taper off from
northwest to southeast on Friday as the front finally exits to the
Tennessee Valley. Post-frontal, vertically-stacked northwesterly
flow will advect a cooler and drier airmass into the area from
Friday night into Saturday. Friday night is primed for widespread
fog formation and ridge-valley splits, and highs are expected to be
slightly below normal values (upper 70s/lower 80s) for the first two
days of the holiday weekend. The upper atmospheric pattern flattens
back out to zonal flow on Sunday, and the resultant height rises
correspond with temperatures moderating back towards near-normal
readings in the mid 80s. Passing disturbances will return rain
chances to the grids to close out the period, but it is too early to
determine what (if any) significant sensible weather impacts might
arise with them.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 148 PM EDT TUE JUN 16 2026

A field of cumulus clouds continues to move across the forecast
area this afternoon with VFR conditions expected at all TAF
locations. A cold front will approach the Ohio Valley near 00Z.
this approaching front could lead to some showers or a stray storm
between 04Z and 10Z overnight, which could affect KIOB or KSYM. Brief
reductions to MVFR would be possible if a location were to be
affected, but confidence was too low to include a PROB30 at this
point. Additionally, patchy valley fog could develop overnight
leading to a reduction into MVFR conditions. However the fog is
not expected to affect the TAF sites.

&&

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

&&

$$

UPDATE...GINNICK
SHORT TERM...JP
LONG TERM...MARCUS
AVIATION...JP/GINNICK