748
FXUS63 KLMK 160745
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
345 AM EDT Thu Oct 16 2025

.KEY MESSAGES...

*  Dry conditions and seasonable temperatures are expected today and
   tomorrow.

*  Warm and windy conditions are expected on Saturday. Wind gusts of
   20 to 30 mph are likely, with high temperatures approaching daily
   records Saturday afternoon.

*  A strong cold front will move across the area late Saturday into
   Sunday morning. There is low confidence in a few strong or severe
   storms with the front. Rainfall amounts should range from 0.50-
   1.50" in most areas, with isolated heavier totals possible.

*  More windy conditions are likely on Sunday, with 30 to 40 mph
   wind gusts likely.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 345 AM EDT Thu Oct 16 2025

This morning, a backdoor cold front is settling across the mid- and
upper Ohio Valley with sfc high pressure extending from the Great
Lakes into the Ohio Valley. A band of stratus clouds sandwiched
between the cooler air mass to the northeast and the warmer air mass
to the southwest will pivot across the northern half of the CWA this
morning before mixing out later today, and mostly sunny skies are
expected for all areas by this afternoon. There should be enough of
a pressure gradient in place for a steady NE breeze around 10 mph
throughout the day. Modest CAA should keep highs today a few degrees
below yesterday, with afternoon readings ranging from around 70
degrees in the KY Bluegrass to the mid-to-upper 70s in the Pennyrile
and Purchase regions.

This evening into tonight, mostly clear skies are expected with a
few thin high clouds moving in overnight from the southwest. With
the sfc pressure ridge axis over the Appalachians tonight, a light
easterly wind should continue in more exposed areas overnight, with
sheltered valleys and rural areas more likely to see calm winds. As
a result, we should see a pronounced ridge-valley split in
temperatures Friday morning, with lows ranging from near 40 degrees
in the coolest valleys to near 50 degrees in the Louisville metro,
as well as for areas south and west of Bowling Green.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 345 AM EDT Thu Oct 16 2025

Friday and Friday Night...

A shortwave trough ejecting across the northern Plains will shift
the upper level ridge axis over the Ohio and Tennessee Valleys for
the day on Friday. In the low levels, surface high pressure will
become established over the Carolinas and Mid-Atlantic region by
Friday afternoon, allowing for some warmer return flow to begin.
This should allow for highs on Friday to be a few degrees above
persistence in spite of a chilly start Friday morning. There should
still be a general NE-SW gradient in temperatures, with highs
ranging from the low-to-mid 70s across the Bluegrass region to near
80 degrees across south central and SW Kentucky.

Friday night into Saturday morning, mid- and upper-level height
falls to the NW of the region should strengthen the pressure/height
gradient over the region, leading to stronger SW flow aloft and S/SE
winds near the surface. This should keep temperatures considerably
milder overnight, with lows about 10 degrees warmer across the area
compared to Friday morning.

This Weekend...

Saturday, broad mid- and upper-level troughing over the central and
northern Plains will begin to approach the Mississippi Valley along
with an associated sfc cold front. As the pressure/height gradient
over the region strengthens during the day, S/SW winds will
increase, promoting strong WAA. Temperatures should surge into the
80s across the area Saturday afternoon, with mid- and upper-80s
possible across southern KY.

Saturday evening into Saturday night, an H5 jet will intensify
upstream of the mid-level trough axis, resulting in height falls and
amplification of the trough as it crosses the Miss. Valley. Upper-
level diffluence and vort. advection should contribute to deepening
of the sfc low which should track across northern IN and toward Lake
Huron by Sunday morning. Low-level response to height falls aloft
should result in a 50-60 kt LLJ moving across the Ohio Valley
Saturday night. As the LLJ passes, PWAT values should increase to
around 1.6-1.7 immediately ahead of the cold front, with a line of
showers and thunderstorms moving across the region late Saturday
evening through mid Sunday morning.

The potential for strong or severe thunderstorms continues to look
very uncertain for our area, as while the wind/shear profile will be
quite impressive, limited instability will constrain the overall
potential. Given that the peak timing for storms in our area looks
to be between 06-15Z Sunday, this will fall during the diurnal
minimum in instability, and model soundings do show poor low-level
lapse rates with most of the instability being above a near-sfc
stable layer. On the other hand, if any stronger cells are able to
develop, it would not be particularly difficult to get near severe-
level winds down to the surface.

Precipitation totals have trended down over the past few model runs,
and convection along the front should be progressive enough to avoid
much training of heavier rain rates. While isolated swaths of 1-2+"
of rain are possible, substantial flooding issues are not expected
at this time.

Behind the cold front on Sunday, steepening llvl lapse rates should
bring about a second wave of stronger wind gusts as CAA overspreads
the area. The ECMWF Extreme Forecast Index value is above 0.8 for
wind gusts on Sunday, with a Shift of Tails around 1, indicating
high confidence in unusually strong wind gusts. Would expect
widespread 25 to 35 mph wind gusts during the day on Sunday, with
the typically windy ASOS locations possibly exceeding 40 mph at
times. Given the strong cold advection, temperatures should be held
down in the 60s during the day on Sunday.

Winds will relax Sunday night as high pressure moves into the region
from the west. This should allow temperatures to drop into the upper
30s and low 40s Monday morning.

Early-to-Mid Next Week...

The large scale pattern is favored to remain progressive and
relatively active over the first half of next week with a series of
upper-level disturbances and associated sfc fronts moving across the
central and eastern CONUS.

The trough associated with the weekend disturbance will be over
southeast Canada on Monday, with low-amplitude upper ridging moving
across the Miss. Valley. Monday should be a dry day, with the
influence of the upper ridge and departing sfc high contributing to
modest temperature recovery. A moderating temperature trend should
continue Monday night into Tuesday as SW flow increases ahead of the
next disturbance.

Model agreement is relatively good in another upper trough and sfc
cold front sliding across the region next Tuesday into Wednesday,
with 12-18 hours timing discrepancies between the various medium-
range guidance. At this time, most ensemble guidance depicts a
relatively broad/open trough, limiting amplification potential and
resulting in a relatively uneventful FROPA with modest amounts of
precipitation and breezy gradient winds. However, we`ll continue to
monitor this disturbance as a more amplified upper/sfc wave could
introduce another strong storm chance during the middle of next
week. Temperatures would be expected to fall again behind this
system next Wednesday into Thursday.

&&

.AVIATION /06Z TAFS THROUGH 12Z FRIDAY/...
Issued at 129 AM EDT Thu Oct 16 2025

Nighttime satellite imagery shows a band of stratus with ceilings
around 4 kft gradually working from east to west across the OH
Valley early this morning. This stratus deck, currently over LEX and
RGA, is expected to filter toward SDF and HNB later this morning
before gradually scattering out by around midday. Ceilings are
expected to remain VFR within this band of clouds, and no impacts to
categories is expected during the current forecast period. We`ll
have to watch for a low chance of some brief fog at BWG and HNB
around sunrise this morning.

Otherwise, winds should again increase out of the E/NE later this
morning, generally remaining between 6-12 kt across the region today.

&&

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

&&

$$

SHORT TERM...CSG
LONG TERM...CSG
AVIATION...CSG