420
FXUS63 KLMK 180056
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
756 PM EST Sun Nov 17 2024

.KEY MESSAGES...

*  Warmer temperatures and mostly dry weather today and tomorrow.

*  The next rain-maker arrives Monday night into Tuesday.

*  A transition to a colder pattern is very likely for mid-late next
   week. There is high confidence for very windy conditions
   beginning Wednesday and continuing through Friday.  Some light
   snows will be possible late Wednesday into early Thursday and
   then again Thursday night.

&&

.UPDATE...
Issued at 755 PM EST Sun Nov 17 2024

Sfc high pressure is located over the southeastern US, which is
resulting in a steady SW return flow. With increasing clouds through
the overnight, we continue to expect a mild night with temps in the
upper 40s and lower 50s. Dry weather should remain given the sfc low
and attendant frontal boundaries remaining to the west, but an
isolated shower may be possible tomorrow just north of our forecast
area. Otherwise, expect a quiet night with some valley fog possible
given the increasing low level moisture. Overall forecast is in
good shape, so no major changes have been made at this time.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 254 PM EST Sun Nov 17 2024

It`s a pleasant afternoon across central KY and southern IN. Mild
air is in place along with broad SW flow aloft. Sfc temperatures are
currently in the 65-70 degree range. We`ve mostly just had SCT thin
cirrus today, which has allowed a good amount of filtered sunshine.
However, we are now seeing BKN lower clouds develop over west-
central KY and SW IN.

A gradually weakening low pressure system is rotating east over
western Ontario, with a cold front draped south through Lake
Superior, IL and MO. This frontal boundary will stall as it sags
toward the I-70 corridor tonight. Expect increasing clouds tonight,
particularly in the lower levels, as increasing moisture advects
into the region from the west. Lows will be fairly mild given the
increased cloud cover, with Monday morning readings in the mid 40s
to lower 50s.

On Monday, a deep area of low pressure will lift northeast through
the central Plains and pull the stalled boundary northward. Slightly
deeper moisture and weak ascent could yield spotty light rain in
southern IN Monday morning. However, lingering dry air in the mid-
levels will limit coverage. Overall, Monday will remain fairly dry
with mostly cloudy skies and mild temps. Highs should range from the
mid/upper 60s in the Bluegrass to the lower 70s in south-central KY.
Debated going another couple of degrees warmer, but the cloud cover
will help keep sfc warming in check.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 254 PM EST Sun Nov 17 2024

Monday Night through Wednesday...

Very well advertised strong surface low will lift from Nebraska into
southwest Ontario Monday night into Tuesday.  A surface warm frontal
boundary will lift northward through the region Monday night with an
arcing cold front to sweep through late Tuesday.  Overall, not
seeing a lot of forcing/lift with the warm front coming through the
region.  However, a long band of rain showers will accompany the
cold front as it sweeps through the region.  Model proximity
soundings across the region do not show much in the way of surface
based instability, but a few of the ensemble member soundings do
show some elevated instability late Monday night into the day on
Tuesday.  Shear profiles, on the other hand, are quite impressive
for mid-November standards.  Given the sounding profiles, rain
showers will be the primary sensible weather feature, though some
rumbles of thunder will be possible here and there.  Overall, the
threat of organized severe weather with this frontal passage is
very low.

Low temperatures monday night will be well above climatology with
readings in the low-mid 50s east of I-65, and mainly in the mid-
upper 50s west of I-65.  For Tuesday, we`ll see a large dry slot
pivot through the region behind the morning convection.  Not sure
how much clearing we`ll see, but it will be down right breezy as the
pressure gradient increases.  Highs on the day should be in the mid-
upper 60s east of I-65, with upper 60s to near 70 in areas west of I-
65.  The actual cold front will move through late Tuesday with lows
Wednesday morning ranging from the lower 40s over southwest IN to
the mid-upper 40s east of I-65.  Generally windy conditions will
continue Tuesday night as well.

For Wednesday, we`ll continue to see breezy/windy conditions across
the region as west-northwesterly winds will continue to advect
colder temps into the region.  Most of the 17/12Z guidance is drier
for Wednesday as we`ll be in a lull between the departing lead
system and the next wave coming down the pike.  Will keep some
slight chance PoPs in this period for this cycle, but current
thinking is that PoPs will likely need to be reduced for Wednesday
in the next forecast issuance.  The main issue for Wednesday will be
the breezy conditions with winds of 15-20 mph and gusts of 25-30 mph
at times.  Highs will generally be in the mid-upper 50s.

Wednesday night through Thursday Night...

Moving into the Wednesday night period, a secondary but strong
perturbation will dive southeast through the Ohio Valley bringing
light precipitation with it.  Thermal profiles across the ensembles
look to stay warm enough for a plain cold rain initially Wednesday
night.  However, toward sunrise Thursday, the profiles do get cold
enough for a mix of rain and snow.  With the coldest air residing
over southeast Indiana and into the Bluegrass region of central
Kentucky, this would be the area where a transition over to light
snow Thursday morning will be possible.  As of this writing,
temperatures will be at or just above freezing.  Ground temperatures
will be quite warm as well, so impacts look to be quite limited.

Thursday will be a cold/raw day across the region with mostly cloudy
conditions.  Winds will shift to the northwest and become quite
gusty through the day.  Wind gusts of 30-35 mph will be common
during the afternoon.  Upslope flow will likely result in some
continuation of snow showers/flurries across our far eastern
sections and into the higher elevations of southeast KY.  NBM temps
for the day are probably too warm, but a gradient of temperature is
likely across the region.  Highs in the mid-upper 30s will be common
across the Bluegrass region with low-mid 40s across our southwest
sections.

Another strong perturbation is likely to push into the region
Thursday night bringing a mix of rain/snow showers back to the
region with overnight lows in the middle 30s.

Friday through Sunday...

Heading into the late week period and into next weekend, the upper
level low over the eastern US is forecast to slowly pull eastward
while an upper level ridge axis builds into the eastern Plains and
into the Midwest.  Drier conditions are expected across the Ohio
Valley through the weekend with cooler than normal temperatures
continuing.  Highs Friday will be be in the mid-upper 40s with
overnight lows in the low-mid 30s.  Highs Saturday will moderate
some with readings in the mid-upper 40s over the Bluegrass to around
50 in the southwest.  Highs on Sunday will likely rebound into the
lower 50s in many areas.

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 615 PM EST Sun Nov 17 2024

VFR conditions currently across the region will continue tonight.
Increasing SCT-BKN clouds coming from the west will lower to low-end
VFR during the overnight, and confidence in MVFR ceilings remains
low. Light winds expected from the SW this evening, becoming more
SSE tomorrow. Patchy cloudiness/breaks in the clouds may allow for
brief fog formation tomorrow morning, but confidence is not high
enough to include in TAFs at this time. For the rest of forecast
period, continued cloudiness expected, though VFR ceilings are most
likely.

&&

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

&&

$$

UPDATE...CJP/JES
SHORT TERM...EBW
LONG TERM...MJ
AVIATION...CJP/JES