Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

150
FXUS63 KJKL 100932
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
532 AM EDT Sun May 10 2026

.KEY MESSAGES...

- A cold front brings chances for showers and a few thunderstorms
  this afternoon and tonight, followed by additional chances at
  midweek.

- Patchy frost is possible late Monday night into Tuesday morning
  in deeper rural valleys and hollows - mainly away from mainstem
  rivers.

&&

.SHORT TERM...(Today through Monday)
Issued at 525 AM EDT SUN MAY 10 2026

Early this morning, an upper level trough extended from the Hudson
and James Bay areas of Canada across Ontario and Quebec across
the Great Lakes into the mid to Lower MS Valley as well as the OH
Valley, TN Valley, and central to southern Appalachians. Further
west, an upper level ridge extends from parts of the eastern
Pacific into the southwest Conus and Great Basin to Northern
Rockies to Alberta. Multiple shortwaves were moving through the
upper trough with one working into the Lower OH Valley region
while another was nearing the western Great Lakes with another
upstream and nearing the Central Plains. At the surface, a ridge
of high pressure was in place across the southeastern Conus into
the Southern Appalachians which has allowed for clear or mostly
clear skies and a moderate ridge/valley temperature split to occur
as valleys have decoupled. Temperatures in the deeper valleys
were in the mid 40s at present while ridgetop and more open
terrain locations were in the 50s. Fog has also developed along
the rivers, lakes, and larger creeks generally south of the Mtn
Pkwy.

Today and tonight, a more northern shortwave rotating through the
upper trough will track across Quebec, the St Lawrence Valley and
the Northeast with the associated sfc low tracking north/northeast
across eastern Canada and allow the trailing cold front to sag
south of the OH River and into eastern KY today. At the same time,
the upstream shortwave will move across the Lower to Middle OH
Valley through the afternoon and this should promote the boundary
continuing to sag south across eastern KY this afternoon and to
the south of the area by evening. The next shortwave meanwhile
should track across the Central Conus and reach the Lower OH
Valley this evening, passing east of eastern KY on Monday morning.
The axis of the upper trough will continue to move eastward
Monday, reaching eastern KY to end the period. With the cold front
continuing to sag south, sfc high pressure begins to build into
eastern KY on Monday.

Valley fog should lift and dissipate within a couple of hours past
sunrise today. Daytime heating to near if not a few degrees above
normal (into the low to mid 70s north to near 80 in the lower
elevations in the south) and dewpoints in the upper 40s to mid
50s should yield lower end instability with MUCAPE of only a few
hundred J/kg, as high as 500 J/kg if not slightly higher per the
00Z HREF and recent HRRR runs. Near the boundary, isolated to
scattered convection should develop as progged by high
resolution/convective allowing models. This may result in trace to
a couple hundredths of an inch in general, with some isolated
amounts in the tenth to a quarter of an inch range. PW per the 00Z
HREF gradually rises today from the 15th to 45th percentile or
the 0.5 inches south to nearly 0.9 inches north to the 50th to
60th percentile or 0.9 to 1.1 inches by early evening. South of
the Mtn Pkwy PW also per the 00Z HREF should generally be in the
50th to 70th percentile range tonight. Although somewhat limited,
this should be enough moisture with the boundary just south of
the region and the passing shortwave for a generalized light
rainfall nearing a tenth of an inch or so from late this
evening/tonight in the central to southern locations. More
northern locations may only pick up a trace tonight if that.

As the boundary continues to sag south and the shortwave moves
east of eastern KY, chances for convection diminish quite quickly
on Monday following sunrise. A trend of decreasing clouds is also
anticipated and drier air should begin to filter in, particularly
in the north as the high begins to build in. Temperatures trend
below normal for highs behind the boundary on Monday.

.LONG TERM...(Monday night through Saturday)
Issued at 425 AM EDT SUN MAY 10 2026

The long term period will open with relatively tranquil weather.
The upper level trough will be departing the northeastern US, with
broad upper level ridging building over the southwestern CONUS.
At the surface, high pressure will continue to build in following
the departure of the cold front. Clear skies associated with this
high pressure will allow for efficient radiational cooling
overnight; thus, lows will be well below average across the
forecast area. MinT guidance has trended slightly warmer since
yesterday, in accordance with models favoring marginally higher
dewpoints on Monday night; accordingly, COOP MOS guidance now
suggests lows in the upper 30s for our most sheltered valleys. If
this more moist trend holds, the primary impact overnight would be
fog formation, especially in river valleys. However, a slightly
drier air mass could allow lows to plummet further and allow for
patchy frost formation in sheltered hollows. This solution is
currently favored by the ECMWF, owing to lower frontal passage QPF
in the northern half of the forecast area. For now, both frost
and fog were kept in the forecast for appropriate valley
locations, but dewpoint trends will continue to be monitored. With
high pressure continuing to dominate and winds becoming more
southerly, Tuesday afternoons highs will rise into the mid 70s.

The next chance for rain will arrive overnight Tuesday into Wednesday.
Following the departure of the original trough, upper level
troughing initially over the Canadian Prairies will dig into the
Great Lakes. At the surface, a well defined low pressure system
will translate eastward across the Great Lakes region with time,
and a cold front extending south from this low will push east into
Kentucky and enter our area by Wednesday morning. Instability
associated with this front will be meager, with the LREF
outputting median MUCAPE of under 500 J/kg ahead of the front;
thus, the main impact will likely be showers and perhaps a few
rumbles of thunder, although given a lack of antecedent moisture,
QPF will likely be low. High temperatures will still rise into
the mid 70s on Wednesday afternoon, before winds become more
northwesterly Wednesday evening and eventually calm overnight.

Following Wednesdays cold front passage, high pressure will build
in yet again, with mostly clear skies on Thursday. Model spread
increases significantly toward the end of the week, with some
indications that another system could enter the area this weekend.
The NBM has attempted to average out these trends by introducing
generalized PoPs towards the end of the period, although
uncertainty remains high at this point.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 235 AM EDT SUN MAY 10 2026

VFR conditions prevailed at issuance time. Some valley fog with
reductions to IFR and in some cases lower was present at non TAF
site locations. At this point, this is not expected to affect the
TAF sites. A sagging cold front will bring small chance for
convection from about 18Z through the end of the period. Recent
trends support the highest chance at KSJS where a PROB30 group was
used for Sunday afternoon to early evening. Brief MVFR reductions
are possible with this activity. Winds will remain shower chances
toward the end of the TAF window but mainly to KSJS. Winds will
remain at generally less than 10KT through the period. Light and
variable winds will prevail through about 14Z, followed by
southwest to west winds that shift to the northwest areawide
through around 00Z. Winds remain light during the last 6 hours of
the period, trending toward the north. A disturbance interacting
with the front may bring greater coverage of convection and higher
chances for sub VFR conditions just after the end of the TAF
period.

&&

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

&&

$$

SHORT TERM...JP
LONG TERM...FAGAN
AVIATION...JP