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000
FXUS63 KLMK 210518
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
118 AM EDT Sun Apr 21 2024

.KEY MESSAGES...

*   Possible frost, especially locations in the Bluegrass Monday
    morning.

*   Showers and a few thunderstorms by Tuesday night into Wednesday

&&

.UPDATE...
Issued at 910 PM EDT Sat Apr 20 2024

Current forecast looks to be in great shape. Upstream satellite obs
indicate copious amounts of mid to high level clouds will stream
into the region overnight. Despite the increased cloud cover, will
still be on the chilly side of climo for this time of year as lows
are still expected to dip into the upper 30s and low 40s. Can`t rule
out some patchy frost in our typical cold spots/valleys if we get
some prolonged clearing and calm winds, but most folks will not be
impacted by it tomorrow morning.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 316 PM EDT Sat Apr 20 2024

Mid-afternoon satellite imagery and observations reveal mostly sunny
skies across the region.  Temperatures were in the upper 50s to the
very low 60s with a breezy northwest wind.  For the remainder of the
afternoon, no significant weather is expected.  Afternoon highs
should top out either side of 60 before falling into the low-mid 50s
by sunset.

Tonight, high pressure will keep things dry across the region.
However, widespread upper level cloudiness will spread into the
region from the west.  The combination of the expected cloud cover
and surface winds expected to remain somewhat elevated overnight
will likely limit the threat of frost across much of the area. There
is still a small chance that some very light patchy frost could
occur across our southern IN counties where some partial clearing of
cloud cover could happen toward sunrise Sunday morning.  Overnight
lows are forecast to dip into the upper 30s across southern IN and
the northern half of KY with lower 40s south of the Cumberland
Parkway.

For Sunday, high cloud cover is forecast to shift to the south and
east resulting in another mostly sunny day.   A continued northwest
flow will keep temps below normal across the area.  Highs Sunday
will likely top out in the upper 50s.  A few spots along the KY/TN
border could hit 60.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 316 PM EDT Sat Apr 20 2024

Shortwave trough will be working through the Ohio Valley at the
start of the period as sfc high pressure over the Central Plains
continues to build over the Lower Mississippi Valley. Behind the
departing shortwave, 850mb temperatures will be around -1 to -2
overnight with clear skies and relatively light winds under 5 mph.
Lows are expected to be around the mid 30s by Monday morning.
Possible frost is still expected Monday morning across central KY
and southern IN with the highest likelihood over the Bluegrass.

High pressure will continue to build in over the region during the
day Monday with slight ridging developing aloft. While still below
seasonal norms temperatures will be a bit warmer with clear skies as
highs warm into the mid/lower 60s.

Upper level system currently over the Pacific NW will track over SW
Canada Sunday, then into the Dakotas and Upper Midwest Monday and
Monday night before pushing into the Great Lakes by Tuesday. This
system will drag a cold front out of the Upper Midwest southeastward
into the Ohio Valley by Tuesday evening/night. As sfc high pressure
pushes eastward, return flow out of the south will increase surface
moisture and advect in warmer air into the region ahead of the
approaching cold front. Highs in the afternoon will be closer to
normal around 70 degrees. Showers and thunderstorms will develop
along the approaching boundary Tuesday and increase precipitation
chances across southern IN and along the Ohio River Tuesday
afternoon with our highest shower/storm chance Tuesday night as the
front pushes through the area.

Wednesday and Thursday will be quiet and dry as sfc high pressure
builds in over the Great Lakes and upper level ridge across the
western US works eastward and over the Ohio Valley b Thursday and
Friday. Highs both days will be in the mid/upper 60s.

The pattern turns warmer and more active for the end of the week
and into the weekend. A system will develop over the central US and
move northeast into the Great Lakes Friday into Saturday. This will
lift a warm front across the Ohio Valley during the day Friday
increasing the chance of showers and storms as an associated
shortwave trough works through the region. Highs will return into
the mid/upper 70s for both Friday and Saturday.

&&

.AVIATION /06Z TAFS THROUGH 12Z MONDAY/...
Issued at 117 AM EDT Sun Apr 21 2024

VFR conditions are expected through this TAF period. Light,
northwesterly winds will prevail in the overnight hours and pick
back up after sunrise. In the afternoon, atmospheric mixing will
bring some momentum aloft to the surface resulting in gusts up to 18-
20kts. Nighttime satellite shows high cirrus moving off to the east
of the region and some more high cirrus moving towards the region
from the west. In the afternoon, SCT Cu will likely move through the
region at about 5kft. Should be a pleasant and sunny day.

&&

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

&&

$$

UPDATE...DM
SHORT TERM...MJ
LONG TERM...BTN
AVIATION...SRM