411
FXUS63 KLMK 281003
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
603 AM EDT Fri Mar 28 2025

.KEY MESSAGES...

* Isolated to scattered light rain this morning across southern
  Indiana/northern Kentucky. Otherwise much warmer today.

* Warm weather continues over the weekend, and widespread light to
  moderate showers are expected Saturday night.

* Confidence continues to increase for strong to severe storms later
  Sunday and Sunday night, which may bring all severe hazards.

* Another strong low pressure system could bring windy conditions
  and thunderstorms, possibly strong, to the region Wednesday into
  Thursday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 335 AM EDT Fri Mar 28 2025

Have some elevated instability across southern and central
IL/IN this hour and watching for any showers/storms that can
develop across our forecast area in the next few hours.
Otherwise, those shower chances should drop as the low-level jet
weakens around sunrise.

Steady southerly winds with that jet this hour will start
mixing down during the morning hours and really establish a nice
warming trend for the region today. We even could see
temperatures at 80 degrees in the warm spots today! Those winds
are because of our placement between high pressure off the SE US
coast and low pressure over the Central Plains. Expect a warm
night tonight, with lows likely staying around 60 for most
Saturday morning.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 335 AM EDT Fri Mar 28 2025

Saturday - Saturday Night...

The weather continues to look very active, and stormy at times,
during the second half of the weekend. However, many should wake up
to dry conditions Saturday morning. An upper level shortwave trough
will be over the Lower MS Valley, with downstream ridging over the
Southeast. Out west, a primary upper level trough will move east
over the Great Basin as a smaller scale shortwave disturbance lifts
northeast over the High Plains. A sub-1000 mb sfc low is forecast to
lift northeast over the central Plains. Downstream, we will see
continued deep SW flow in a broad warm sector.

The upper level shortwave disturbance over the Lower MS Valley is
forecast to lift northeast and move over the area Saturday night.
This feature will coincide with a surge in moisture transport
Saturday evening and overnight, as well as strengthening of the
already healthy SW low-level jet in place. Rain chances will
increase Saturday afternoon, especially west of I-65. However,
expect more widespread light to moderate showers Saturday evening
and overnight.

Highs Saturday will be tempered somewhat by abundant cloud cover,
but still expect at least low to mid 70s. Our warmest locations in
the Bluegrass/Lake Cumberland regions should reach the upper 70s.
Saturday night into early Sunday looks mild and rainy, with lows in
the low 60s.

Sunday - Sunday Night...

A complex scenario will unfold Sunday into Sunday night, and at
least some of the mesoscale details will require a bit more time to
become clear. Primary upper level wave and associated mid-level
shortwave energy is forecast to lift northeast from the central
Plains across the Midwest and Great Lakes. A deepening sfc low is
forecast to accelerate northeast across the Great Lakes and into
Canada during the period, dragging a strong cold front through
southern IN and central KY Monday morning.

The Sat night wave/showers will lift off to the northeast Sunday
morning, which should then be followed by a lull in precip that
lingers into the afternoon. Strengthening mid-level capping during
the afternoon could very well keep us relatively dry until 00-06Z
Mon, when the mid-level trough and sfc cold front approach from the
west. Any clearing in the cloud cover looks questionable, but the
environment will gradually destabilize during this time with
steepening lapse rates aloft and low-level moistening.

Deep convection is likely to initiate just ahead of the sfc cold
front and push west to east across the forecast area Sunday evening
into early Monday. This will be a nighttime event, which does
increase the level of concern a bit. Storm mode still appears likely
to be linear, given fairly deep SW flow and shear vectors roughly
parallel to the boundary. However, could definitely see
supercellular structure in any cells within or just ahead of the
line. Low-level and deep-layer shear are both impressive, with
hodographs showing clockwise curvature in the lower levels.
Instability, especially sfc-based, is a bit more questionable. Up to
500-1000 J/kg MUCAPE should easily sustain strong to severe storms
into the CWA. Much of this energy could end up elevated in nature
much of the overnight period, though it will be close with sfc
dewpoints creeping into the low 60s. A consensus of various
deterministic and ensemble model soundings suggests an environment
conducive for scattered damaging wind gusts and perhaps some
tornadoes. Severe hail is also a concern given the decent lapse
rates aloft and very strong vertical shear.

Monday - Tuesday Night...

Conditions dry out from west to east on Monday behind the departing
cold front. Expect cooler conditions than the preceding days, with
temperatures back in the 50s to low 60s. The cool, dry conditions
will continue through Tuesday with ridging building across the
region. Lows in the 30s are expected Monday night/early Tuesday, and
frost will be possible. Temps will warm back into the mid 50s to low
60s in the afternoon. Tuesday night is likely dry as well, but
warmer as we get back into a strong WAA pattern ahead of a deep area
of low pressure over the central Plains.

Wednesday - Thursday...

Another strong low pressure system may impact the region Wednesday
into Thursday. Model guidance suggests another strong sfc low could
develop along a similar track as the previous storm, generally from
the Plains northeast into the Midwest and Great Lakes. This would
bring windy conditions on Wednesday, with likely rain and possible
strong storms by Wednesday PM into early Thursday.

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 603 AM EDT Fri Mar 28 2025

Still have some pretty good winds just above the surface over our
region, so will keep in the llws another hour or two. By mid morning
each site should see some wind gusts with SSW to SW winds continuing
most of the day before dying down this evening, and perhaps seeing
another round of llws. No concerns for cigs or vsby though...and
higher cigs should scatter out during the day today as well.

&&

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

&&

$$

SHORT TERM...RJS
LONG TERM...EBW
AVIATION...RJS