Shelbyville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

519
FXUS63 KLMK 201742
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1242 PM EST Sat Dec 20 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Up and down temperatures expected this weekend as a dry cold front
  moves through the region tonight.

* Off and on chances for light rain showers are expected Monday
  afternoon through Wednesday, though a washout is unlikely.

* Unseasonably warm temperatures are likely around Christmas, with
  highs in the 60s to around 70 likely from Christmas Eve through
  Friday.

&&

.UPDATE...
Issued at 1144 AM EST Sat Dec 20 2025

The forecast is on track today for a mostly sunny, occasionally
gusty, and mild overall day. Did lower dew points down to NBM 10th
percentile for this afternoon and evening to account for good BL
mixing and expected dry air mix down. Overall, little consequence on
the overall forecast as sensible weather isn`t really affected and
the fire weather season has ended.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 306 AM EST Sat Dec 20 2025

This morning, mostly zonal upper level flow is present across the
CONUS as the trough which brought a cold front through the region
Friday morning has quickly exited toward the Canadian Maritimes. A
broad area of sfc high pressure is analyzed from the central
Appalachians down into the southeast US, while sfc low pressure
extends from the MB/ON border southward into the central Plains.
While most areas have fallen into the 20s across southern IN and
central KY, milder temperatures are located immediately to our west,
as southerly flow is bringing WAA into the Ozarks and mid-MS Valley.

As we head through the day today, an upper shortwave over the
Canadian prairies is expected to pivot to the E/SE across the upper
Great Lakes. As it does so, the associated sfc cold front across the
Plains will move eastward across the Mississippi Valley, passing
through the area this evening into tonight. Winds will increase out
of the S/SW later this morning, with wind gusts of 20-30 mph likely
as momentum from a LLJ moving over the region mix down by around
midday. Strong warm advection should help temperatures recover into
the 50s this afternoon, with a mix of sun and mainly high clouds
expected through the day.

Later this afternoon into this evening, a narrow tongue of greater
850-925 mb moisture will attempt to nose into the region from the SW
ahead of the cold front. While this moisture surge should be
sufficient to increase low-to-mid level cloud cover this evening,
the overall lack of deep moisture should curtail precipitation
chances, even with FROPA. With that being said, a spotty sprinkle or
light rain shower can`t be ruled out south of the KY Parkways this
evening, though impacts should be minimal. Winds are expected to
swing around to the NW with FROPA, bring CAA back into the region by
Sunday morning. Temperatures Sunday morning are expected to range
from the upper 20s across southern IN to the mid 30s along the KY/TN
border.

For the day on Sunday, cool and dry weather is expected as high
pressure settles into the Ohio Valley. Lingering clouds across KY in
the morning should gradually dissipate as broad subsidence dries out
the column. Light northerly flow will keep weak cold advection going
through the day, with high temperatures expected to range from near
40 across southern IN to the mid-to-upper 40s across southern KY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 306 AM EST Sat Dec 20 2025

Sunday night into Monday morning, seasonably cool and dry conditions
are expected to continue as sfc high pressure starts to push east
toward the central Appalachians. Low temperatures Monday morning
should sink into the 20s in most areas.

Monday will begin a transition to a milder pattern, with fairly good
confidence in this pattern remaining in place through Christmas and
into next weekend. An upper trough will progressively dig off the
west coast of the US over the first half of the upcoming week, with
downstream ridging over the south central US building northward at
the same time. This will place the Ohio Valley into a NW flow
pattern for much of the first half of next week, though the coupled
subtropical/polar jet is expected to lift well to the north into
southern Canada. While several shortwaves are expected to slide from
NW to SE within the main baroclinic zone, our region should be on
the southwestern edge of the best forcing, resulting in fairly
limited impacts.

The first of the above-mentioned shortwaves is expected to slide
across the Canadian Prairies and into the upper Great Lakes Monday
night into Tuesday. While the main portion of the disturbance will
remain well north of the area, S/SW low-level flow is expected to
pick up enough moisture lingering over the Gulf states to support
some warm advection/isentropic lift rain showers Monday afternoon
into Monday night. These showers are expected to be light, with
precipitation amounts of a tenth of an inch or less expected in most
areas.

A cold front is expected to approach from the NW on Tuesday morning;
however, given the persistent building ridge to our SW, this front
is unlikely to make it completely through the region, with most
progs showing it stalling out somewhere over KY/TN Tuesday night.
With ample moisture remaining along the front, scattered showers,
ample cloud cover, and possibly some drizzle will continue into
Tuesday and Tuesday night. While NBM PoPs may be a touch overdone
given limited QPF, think the general message that anyone could see a
light rain shower on Tuesday is appropriate.

The upper ridge is expected to spread eastward Tuesday night into
Christmas Eve, causing the decaying cold front near the area to lift
back to the north as a warm front, increasing warm return flow into
the area. While Monday and Tuesday should see a gradual warming
trend, with highs mostly in the 50s and lows in the 40s, the peak of
the warm temperatures are expected from Christmas Eve through
Friday. High temperatures are expected to surge into the 60s across
the area, particularly on Christmas Day, when probabilities of
exceeding 70 are around 50% across much of south central KY. While
low chances for rain showers currently linger into Christmas Eve and
Christmas morning, most areas should remain dry, especially by the
second half of Christmas Day once the upper ridge axis builds
overhead.

By the end of the week into early next weekend, the medium range
ensemble consensus suggests that the upper ridge will begin to break
down, or at least flatten out a bit as some of the energy from
troughing along the west coast ejects out across the central CONUS.
This should bring returning chances for precipitation and a downward
trend in temperatures; however, details on the magnitude of the cool-
down and precipitation chances are still modest at this time. With
that being said, there doesn`t appear to be any pattern reversal in
store through New Year`s, with elevated chances of above normal
temperatures persisting in the current CPC 8-14 day outlook.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 1242 PM EST Sat Dec 20 2025

Pretty quiet TAF period in store, despite a cold frontal boundary
moving through and some brief LLWS concern this evening at LEX/RGA.
Look for VFR conditions through the TAF period with only some SCT
high clouds to speak of today. Steady SSW winds between 10 and 15
mph will occur, with occasional gusts mostly in the 20 to 25 mph
range.

Winds slacken early this evening, and veer to a SW, then W, and NW
component late evening into the overnight as a dry cold front passes
through the area. Will see a brief uptick in Sct-Bkn mid level
clouds 4-5 k feet from early evening through late evening. Then,
look for a return to upper sky cover. Sunday morning brings Sct-Bkn
upper sky cover with a light N to NNE wind. Brief LLWS threat ends
at LEX/RGA by late evening.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE...BJS
SHORT TERM...CSG
LONG TERM...CSG
AVIATION...BJS