886
FXUS63 KLMK 052352
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
752 PM EDT Tue May 5 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Waves of showers and thunderstorms are expected this evening into
  Wednesday, bringing widespread beneficial rainfall to the area.
  Widespread rain totals of 1-2" are likely, with localized heavier
  totals possibly leading to a few instances of high water or minor
  flooding.

* High temperatures look to warm back into the 70s this weekend,
  ahead of a cold front on Sunday. Showers and some strong storms
  will be possible on Sunday.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 354 PM EDT Tue May 5 2026

The MCV that was mentioned in the previous forecast discussion is
currently draped over the northern portions of our CWA, slowly
departing to the northeast. With little instability over our area,
the system has weakened to one of light-to-moderate rain showers
with a very isolated rumble of thunder.

Looking ahead to this evening, the frontal boundary over central
Indiana and southern Illinois is slowly beginning to move southward
towards our area. As the front moves in, a mid-level shortwave
enters from the west, with a 40-50 kt low-level jet forming beneath
it across our CWA. The combination of this, along with deep moisture
transport and hi-res guidance depicting a developing surface low
near our area along the boundary will help support multiple rounds
of showers and isolated-to-scattered thunderstorms this afternoon
through tonight. Guidance continues so show between 1-2" of rainfall
from this event, with some locally higher totals if training storms
along the front take place.

HREF guidance continues to keep our area in limited instability (<
250 J/kg MLCAPE) that will quickly decrease after sunset this
evening. This should help limit the potential for strong-to-severe
storms to develop, which is helpful given the impressive overall
wind shear profile over our area tonight. Plenty of speed and
directional shear will be present, with HREF guidance showing a peak
0-3 km SRH > 650 m2/s2 shortly after midnight. The elevated nature
of this setup does show up in the ESRH, with values less than 60
m2/s2 depicted throughout the event. The SPC continues to have our
far western counties under a marginal risk for severe weather, with
the primary threat being damaging winds. An area of interest early
this evening will be in the SW portions of the CWA once showers and
storms begin to develop. Dew point depressions of 15-20 degrees F
and dry near-surface conditions could create an inverted V profile
at the low-levels, and with the formation of a strong low-level jet
this evening, gustier winds could be experienced by some of those
showers and storms.

By Wednesday, the front slowly departs to the southeast, becoming
nearly stationary over northern Tennessee. With multiple
perturbations riding the front, rounds of rain showers will be
possible (35-50%) over our southern counties, with accumulations
less than 0.75" forecast. For the rest of the area, expect dry and
cool conditions, with highs in the low 60s. By Wednesday night,
surface high pressure will begin to build in, helping push the near-
stationary front away from the region and ushering in a period of
calmer weather.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 354 PM EDT Tue May 5 2026

===Dry and Cool Thursday and Friday===

Broad troughing and surface high pressure will keep conditions dry
and cool through the end of the week. Looking to see highs in the
mid-upper 60s and lows in the upper 30s and low 40s on Friday
morning. Some areas in the far northeastern Bluegrass may see mid
30s, where some frost development will be possible.

===More Active Weather This Weekend===

Late Friday night and into Saturday morning, a shortwave trough will
amplify as it swings through the Upper Mississippi Valley and into
the Ohio Valley. This feature will allow a surface low pressure to
develop and move through the Great Lakes, dragging a cold front
southeast through the lower Ohio Valley. Southwesterly flow out
ahead of the cold front will allow for moisture and temperatures to
increase. A line of showers is expected along the front and some
embedded thunder will be possible, given weak elevated instability.

Behind this front, showers will quickly dissipate as surface high
pressure builds in behind. We won`t see much of a dip in
temperatures, since southerly flow will return quickly on Saturday
afternoon. Looking to see temperatures in the mid-upper 70s for
Saturday.

On Sunday, a shortwave ejecting out of the desert southwest will
move through the Tennessee Valley. This feature will develop a
surface low pressure system. At the same time, broad troughing over
the Great Lakes will try to bring another wave through the Ohio
Valley. These two features may phase, but for now thinking the
southern stream shortwave will precede the northern stream wave.
Numerous showers and some storms are expected for Sunday. Looks like
we will see 1000-1500J/kg of SBCAPE, but weaker shear (30kts of 0-
6km Bulk Shear). Will continue to monitor Sunday for severe storms
potential.

===Drier Early Next Week===

High pressure will follow the cold front on Sunday night, bringing
drier and cooler air to the start of next week.

&&

.AVIATION /00Z TAFS THROUGH 06Z THURSDAY/...
Issued at 751 PM EDT Tue May 5 2026

Rain showers mixed with small embedded thunderstorms are moving in
from the SW this evening near and along an approaching cold front.
Showers with the occasional storm will continue over the next few
hours with better rain/storm coverage at HNB/SDF/BWG. Rain with
lowering cloud heights and a shift in winds at the surface blowing
from the NNE will move across all airports in this TAF period from
west to east.

HNB has already had a shift in winds with lowering cloud heights to
IFR conditions. These IFR conditions will move across all airports
over the next several hours. Additionally, embedded thunderstorms
moving in broken lines with rain will continue overnight as the cold
front sweeps through. HNB ends rain first, with all other airports
seeing a break in rain showers by 12-13Z before scattered showers
return Wednesday afternoon. The general flight rule trend is that
IFR conditions occur for everyone through the overnight, returning
to MVFR by Wednesday morning. VFR returns late into the TAF period
Wednesday afternoon except for BWG.

&&

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

&&

$$

SHORT TERM...BEN
LONG TERM...SRW
AVIATION...BKF