503
FXUS63 KLMK 191959
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
359 PM EDT Thu Mar 19 2026

.KEY MESSAGES...

* Breezy SW winds and mild temperatures expected on Friday ahead of
  a cold front. A low chance for showers and storms exists across
  the KY Bluegrass Friday night.

* Warm temperatures continue this weekend, with highs in the 70s and
  80s expected. Another chance of showers and thunderstorms is
  expected Sunday night, with a low, but increasing chance for
  strong storms.

* Cooler and mainly dry conditions are expected early next week.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 359 PM EDT Thu Mar 19 2026

This afternoon, mostly sunny skies are present across the region as
temperatures have warmed into the mid-to-upper 60s and low 70s
across central KY and southern IN. Mild temperatures and dry weather
is expected to continue into the overnight hours tonight, with lows
only expected to fall into the mid-to-upper 40s and low 50s.

A weak mid-level shortwave is expected to transit across the Great
Lakes within the broader NW flow pattern late tonight into Friday,
with sfc low pressure developing in association with this system.
While the sfc low will track across Ontario and into the northeast
US on Friday, a sfc cold front extending back to the southwest will
approach the Ohio Valley from the north. Initially, the main impact
from this front will be increasing south and southwesterly winds
during the day on Friday. Sustained winds should be on the order of
10-15 mph in most locations, with gusts of 20-30 mph expected during
the late morning and early-to-mid afternoon hours. While there is
not expected to be a whole lot of moisture return with this system,
it should be sufficient for increased cloud cover tomorrow,
especially east of I-65. Even with the greater cloud cover,
temperatures will continue to warm ahead of the front, with highs
expected to range from the low 70s along the I-75 corridor to the
mid-to-upper 70s west of I-65.

Tomorrow evening into tomorrow night, the cold front will sink into
the region from the north, though it is expected to be weakening as
the best upper-level support slides well to the east of the region.
Low-level moisture will try to pool just ahead of the front, with
sfc dewpoints expected to rise into the mid 50s. While model
soundings do show a pool of instability above a fairly stable layer
near the sfc, it is very uncertain whether forcing will be
sufficient for any showers or storms to develop. SPC has placed
portions of our KY Bluegrass counties into a Marginal Risk for the
potential that a few cells will develop, but notes that this is a
highly conditional threat. With the preponderance of hi-res guidance
showing little to no convective development Friday evening, think
that the overall severe threat is very low, but we`ll continue to
monitor trends in guidance tonight into tomorrow. If any strong
storms develop, hail and gusty winds would be the main severe
threat. Otherwise, temperatures will remain mild Friday night, with
lows only falling into the upper 40s and low-to-mid 50s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 359 PM EDT Thu Mar 19 2026

The expansive upper ridge over the western US will flatten out this
weekend as higher height anomalies spread to the east into the Ohio
Valley. The weak sfc cold front which passes through the area
tomorrow evening should dissipate on Saturday, with a fairly
weak/stagnant flow regime overhead during the first part of the
weekend. Clearing skies during the day on Saturday combined with
increasing heights aloft should allow temperatures to warm into the
70s across the area Saturday afternoon, with highs around 80 degrees
possible in southern KY.

For the second half of the weekend, broad sfc low pressure over the
central Plains will begin to interact with a developing upper
shortwave over the northern Plains and the Canadian Prairies. While
this disturbance is expected to amplify Sunday into Sunday night,
the main area of ascent and support for sfc cyclogenesis is expected
to track to the northeast of the area, with the sfc low pressure
remaining fairly steady-state while sinking into the Ohio Valley
Sunday afternoon and evening. Ahead of this system, breezy SW winds
should bring about another surge in temperatures on Sunday, with
highs expected to reach the low-to-mid 80s Sunday afternoon. What
would be of potentially greater impact would be how much near-sfc
moisture can return ahead of the system, as a pool of instability
will attempt to develop Sunday afternoon and evening over the area.

As the upper trough amplifies Sunday night, it should push a cold
front through the area which will drop temperatures by Monday. This
should be sufficient forcing to get a line of showers and
thunderstorms to develop over the Ohio Valley, especially the
farther north and east you go. Machine learning severe convection
algorithms do show a modest (but increasing) signal for strong to
severe storms Sunday evening into Sunday night, though it is by no
means a slam dunk. Several model soundings show a stout warm
layer/capping inversion aloft until right before cold FROPA,
especially for points to the south and west. Convective coverage may
be somewhat limited as a result, and precipitation amounts should be
limited overall. If any stronger convection is able to develop, some
hints of an EML in sounding data would lead to increased potential
for hail or gusty winds in storms, and while the tornado threat is
very low, one can`t be ruled out.

Early next week, there is fairly good agreement in a few days of
cooler and drier conditions as high pressure sinks into the region
from the north. By the middle of next week, NW flow should continue
over the eastern US; however, there is a consistent signal in a few
weak upper perturbations which could kick off a few transient
systems. Timing in these systems next week varies between ensembles;
however, in general, expect increasing chances for rain by next
Wednesday. Temperatures will also be on an upward trend by the
middle of next week as upper ridging over the western US again
spreads to the east.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 141 PM EDT Thu Mar 19 2026

VFR conditions are expected during the current forecast period with
scattered mid- and high-level clouds expected to return tonight into
the day on Friday. Winds should generally be less than 10 kt out of
the S/SW this afternoon, becoming light out of the south tonight.
Tomorrow morning, a cold front will approach the region from the
northwest. Ahead of the front, winds will increase out of the SW,
becoming gusty after 14Z. Wind gusts of 20-25 kt will be possible
during the late morning and afternoon on Friday, especially at LEX,
RGA, and SDF.

&&

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

&&

$$

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