Louisville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

973
FXUS63 KLMK 041945
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
345 PM EDT Mon May 4 2026

.KEY MESSAGES...

* Waves of showers and thunderstorms are expected Tuesday 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,
  with isolated to scattered rain showers.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 344 PM EDT Mon May 4 2026

This afternoon, mostly sunny skies are noted on satellite imagery
with a mixture of lingering high clouds and a few stratocu where sfc
dewpoints have crept up into the mid-to-upper 50s. Temperatures are
warm across the area, with latest obs ranging from the mid-70s to
around 80 degrees. We should be able to add 1-3 more degrees this
afternoon, reaching highs in the upper 70s and low 80s. The sunshine
has allowed for relatively deep mixing to occur, with latest SDF
ACARS soundings showing the PBL mixing to around 875 mb. This has
allowed 20-30 mph wind gusts to make it down to the surface, and
gusty winds should continue through early this evening when typical
nocturnal decoupling begins.

The current synoptic pattern across North America features a
disjointed series of upper lows/troughs, with a broader upper low
across Ontario and a secondary cutoff upper low extending across
CA/NV. These features are reflected at the sfc as an elongated cold
front which extends from the southern Plains across the mid-Miss.
Valley and into southern Ontario this afternoon. Over the next 24-48
hours, a shortwave on the western flank of the upper low over Canada
will assist in ejecting energy from the cutoff low over the western
US across the southern Plains and toward the Ohio Valley. This will
help to nudge the sfc cold front gradually through the area by
Wednesday evening. Between now and then, low-level response to the
ejecting energy aloft will draw moisture northward from the Gulf,
bringing rounds of showers and storms to central KY and southern IN,
beginning Tuesday and continuing through much of the mid-week period.

Tonight, convection firing from eastern MO over to central IN may
approach our southern IN counties, especially after midnight.
However, as showers and storms approach the area, increasingly dry
air between the sfc and 700 mb should lead to a weakening in any
precipitation. Still, we`ll carry a 20-30% PoP for areas north of
the Ohio River late tonight, with precipitation amounts mainly less
than 0.10". Otherwise, increasing south-southwest flow aloft should
translate down to the surface as a persistent 5-15 mph southerly
breeze, helping to keep temperatures considerably milder than
previous nights. Most locations should drop into the mid-to-upper
50s early Tuesday morning, with temperatures remaining fairly steady
as clouds increase from the northwest early Tuesday.

During the day on Tuesday, southwesterly flow at 850 mb should
strengthen from around 35-40 kt in the morning to 45-50 kt Tuesday
night. This persistent flow regime will draw Gulf moisture
northward, with HREF PWATs exceeding the 90th percentile of
climatology (1.4-1.6") by Wednesday morning. Ongoing convection over
the Ozarks tomorrow morning should move into the areas west of I-65
just before lunchtime, with HREF paintball plots of >30 dBZ
increasing from west to east across the area from late morning
through the afternoon hours. Since this activity will be on the
leading edge of the greatest moisture axis, it will likely dissipate
somewhat as it moves east, and precipitation chances will remain
lower until later tomorrow afternoon and evening along and east of
US 127.

From the middle of Tuesday afternoon through the end of the short
term forecast period Wednesday morning, additional waves of showers
and embedded thunderstorms are expected to slide from west to east
across the region as the strengthening moist S/SW flow aloft lifts
up and over the southeastward-moving sfc cold front. The amount of
coverage of thunderstorms is a bit uncertain, but should generally
decrease the farther NE you go as HREF MUCAPE progs show the sector
of non-zero CAPE diminishing. By late Tuesday night into Wednesday
morning, the sfc cold front should begin to cross the area. One
thing we`ll have to watch is if the sfc front is slower to push to
the south, there would be more time for greater low-level moisture
to sneak into south central KY. Right now, most model soundings show
convection remaining elevated with minimal SBCAPE making it into the
area given deep saturation through the column. If convection were to
become surface-based, ample curvature in hodographs along with a
strong llvl wind field would support a conditional severe threat
across our southwestern counties; however, this is low confidence at
this time.

For rainfall totals through Wednesday morning, the heaviest rainfall
amounts should fall along and north of the Kentucky Parkways, though
areas south of the Parkways will see better chances of rain during
the day on Wednesday (see below). 24-hr QPF LPMM from the HREF shows
the higher end potential with any training convection with swaths of
2-3, even 4" of rain possible, with the best chances for this
occurring west of I-65 and near the Ohio River. While these heaviest
amounts could lead to local high water issues, antecedent dry
conditions and the relatively lengthy period of time over which this
rain should fall should limit the overall flooding threat.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 344 PM EDT Mon May 4 2026

The above mentioned cold front will continue to move SE through the
Ohio Valley with persisting rain showers through the day Wednesday.
The cold front is expected to make its way out of the Bluegrass and
Lake Cumberland region between 15-18z. Rain chances will gradually
decrease NW to SE moving out of western KY as showers linger behind
the front. QPF amounts between 1-2 inches are expected across the
region with this system. Temperatures will only warm to the low to
mid 60s across the area with nighttime lows in the mid 40s. Other
than slight chances (<20%) for scattered rain showers Thursday,
majority of the area should stay dry as surface high pressure moves
in behind the cold front.

Skies will start to clear Thursday afternoon/ evening with this
region of sinking air. Friday`s temperatures are expected to warm
back into the 70s with mostly clear skies. Another low-level
shortwave will bring the rain chances back Friday evening. Light
rain showers will mostly move through southern IN and the Bluegrass
region overnight Friday into Saturday morning. Due to drier air
aloft, QPF amounts are minimal for these scattered showers. Winds
have a potential to become gusty around 30mph as these showers move
in Friday evening.

Multiple shortwaves will keep isolated to scattered showers in the
forecast for most of the weekend. A moisture transport axis will
stretch across the Ohio Valley Sunday afternoon as another boundary
approaches with rain and possible thunderstorms. This could be
another chance for some healthy rainfall totals if ample moisture
can make its way in from the SW. Guidance currently reveals an area
of 1000 - 1500 J/kg SBCAPE Sunday evening, however a very marginal
shear profile. Therefore, at this time no major severe threats are
expected. There is low confidence with this event due to it being 6
days out still.

&&

.AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 148 PM EDT Mon May 4 2026

VFR conditions are expected to continue through most of the current
forecast period, with scattered to broken high clouds continuing
this afternoon into tonight. Breezy S/SW winds sustained around 15
kt with gusts of 22-28 kt will continue this afternoon before
becoming less gusty after sunset. Late tonight into early Tuesday
morning, showers and a few embedded storms will begin to approach
the area from the NW, with HNB/SDF having a slight chance (20-30%)
to see a shower after 08Z. Mostly dry conditions should continue
until around the end of the current forecast period, with more
widespread showers and storms, along with lower CIGs/VIS, expected
later Tuesday afternoon into Tuesday night.

&&

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

&&

$$

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