453
FXUS63 KLMK 070301
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1001 PM EST Thu Mar 6 2025

.KEY MESSAGES...

* Low chance (20% PoP) for light wintry precip early tomorrow
  morning over southern Indiana and northern Kentucky. Impacts not
  expected at this time.

* Widespread rain chances increase Friday evening.

* Warming trend begins Sunday and continues into next week. Highs in
  the 60s on Monday and 70s on Tuesday.

&&

.UPDATE...
Issued at 1001 PM EST Thu Mar 6 2025

02Z surface analysis reveals high pressure centered over Tennessee
with a developing low ejecting east of the Rockies over Colorado.
Winds have gone light and variable across the region in the presence
of the slackening pressure gradient, and light winds are expected to
continue through the overnight hours. Nighttime microphysics
satellite imagery shows a broad band of mid-level clouds moving
toward the area from along and west of the Mississippi Valley. As
mid-level troughing ejects east of the Rockies late tonight, these
clouds should overspread the region, with noteworthy moisture
advection expected above 850 mb through sunrise on Friday.

Within mid-level warm frontogenesis, a band of light precipitation
is expected to develop from SE IA down into SW IN after midnight.
Some light precipitation cannot be ruled out, primarily along and
north of I-64 early tomorrow morning; however, the lowest 5-8 kft
will be slow to saturate, so much of the precipitation aloft should
evaporate. As a result, will carry a slight chance PoP from 08-13Z
across our southern IN and northern KY counties. Thermal profiles
suggest that precip might start off as light rain or sprinkles and
transition to light snow or flurries as the wet-bulbing effects take
place. Regardless, moisture availability will be fairly sparse, so
not expecting much in the way of impacts at this time.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 239 PM EST Thu Mar 6 2025

Skies continue to clear from west to east this afternoon as high
pressure builds in. Winds have eased some and will continue to ease
through the evening hours.

Tonight, ridging will broaden and move over the region and surface
high pressure will start to shift east of the region. Winds will
back to the south by morning and pump warmer air into the region.
The first half of the overnight period will feature clear skies and
ample radiational cooling. In the early morning, high clouds will
move over the region and begin to lower ahead of a weakening low
pressure and associated shortwave trough approaching from the west.

Isentropic lift along the warm front will bring PoPs into the
region. In the early morning, most of the precip should stay to the
north, however, our northern tier of counties will have light PoPs
in the dawn hours. Model soundings still show a dry layer below the
DGZ, which will lead to light precip or drizzle. PType will likely
be a wintry mix of rain, snow, and very light freezing drizzle.

Temperatures will quickly warm on Friday, with high temperatures
expected to be in the mid to upper 50s and low 60s in southern
Kentucky. In the later afternoon, PoPs will begin to increase from
the west as the low pressure center and associated cold front begin
to move over southern Kentucky. Scattered rain showers are expected
later tomorrow afternoon and into the long term period.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 239 PM EST Thu Mar 6 2025

===== Friday Night - Sunday =====

Sfc low pressure will be across the Wabash River Valley Friday night
and into Saturday morning, with increasing moisture and forcing from
a LLJ to increase PoPs across the region. With deeper moisture
expected by the overnight, precip coverage will increase, though QPF
remains fairly light with this wave. Precip amounts under 0.10" is
forecast.

As the sfc low rotates through the area, a trailing cold front will
sweep through, bringing a wind shift to a colder NW flow by Saturday
morning. Some lingering precip along or behind the front could
support light rain or drizzle after sunrise on Saturday in our east,
though the post-frontal airmass should dry out the column as the
morning progresses.

Weak high pressure will stretch into the Ohio Valley from the west-
northwest for the rest of the day, which will help keep a cooler
advection pattern in place. With increasing sunshine for most, we
should be able to hit the lower 50s on Saturday.

A more amplified upper trough will pivot across the southwestern US
over the weekend, which is expected to bring another system across
the Deep South. It still appears we will remain dry for southern
Indiana and central Kentucky Saturday night. Better precip chances
will remain just to our south. The GFS continues to have a northern
bias compared to the ECMWF, though soundings across south-central
Kentucky suggest we should have a rather dry layer in the lower
levels.

Sunday will feature increasing sunshine again as the southern
shortwave shifts east of the region. With strong upper ridging
taking shape across the western US, we should have dry weather for
Sunday and temps in the upper 50s.

===== Monday - Wednesday =====

Sfc high pressure remains over the Ohio Valley for the first half of
next week as the upper flow takes on a more zonal component. With
WAA regimes building over the area, expect warming temps each day
early next week, with 60s on Monday, low 70s on Tuesday, and mid 70s
on Wednesday. It will be a very pleasant start to the week.

Despite the very nice start to the week, we will need to keep eyes
on potentially two waves next week, possibly one Wednesday night
into Thursday morning, and another in the extended for the end of
next week.

A deep upper low will come ashore over southern California on
Tuesday, which will track across the southern US. This wave could
bring a line of showers and storms to the area by Wednesday night
and into Thursday morning. NSSL machine learning guidance does
indicate a broad area of severe probability, though it`s far too
soon to begin getting too deep into details.

Another wave appears possible for the late week or weekend, which
has been highlighted by the NSSL ML guidance as well, in addition to
GFS/ECMWF deterministic solutions. The experimental CPC risk of
heavy precip (latest issuance is 3/5 as of this writing) does
highlight portions of KY for the 3/14-3/15 time frame.

&&

.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 635 PM EST Thu Mar 6 2025

VFR conditions continue tonight with mid- and high-level clouds
moving across the region from NW to SE. Sfc high pressure will cross
the area overnight, with winds expected to be light and variable at
all terminals through sunrise tomorrow. Mid-level moisture will try
to build downward between 06-12Z Friday from NW to SE. While this
could be enough for a sprinkle/flurry to develop, confidence is low
and significant impacts are not expected.

A low pressure system will move into the region from the west on
Friday, with winds increasing out of the S/SE during the mid-morning
hours. The best chance for wind gusts to around 20 kt Friday
afternoon is at BWG, HNB, and SDF, with lower chances at eastern
terminals. Ceilings should gradually trend downward from NW to SE
through the afternoon hours tomorrow as the low pressure moves
closer to the region.

&&

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

&&

$$

UPDATE...CSG
SHORT TERM...SRW
LONG TERM...CJP
AVIATION...CSG