073
FXUS63 KLMK 051918
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
318 PM EDT Fri Jun 5 2026

.KEY MESSAGES...

* Mostly dry weather expected through Saturday, with afternoon highs
  in the mid to upper 80s.

* Muggy summertime conditions return this weekend along with daytime
  shower and storm chances. Rain chances should continue through at
  least next Wednesday, with the highest chances expected Monday and
  Tuesday. Severe weather is unlikely, but heavy rainfall in showers
  and storms could lead to localized flooding.

* Slightly above average temperatures continue through the first
  half of next week with upper 80s and low 90s.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 317 PM EDT Fri Jun 5 2026

High level clouds are currently moving over the area as the surface
high pressure continues to move SE out of the region. Several
shortwave disturbances will bring gusty winds and rain chances back
to the Ohio Valley. Southerly flow will continue to bring moisture
and warm air tonight into tomorrow. Nighttime temperatures tonight
will cool into the mid 60s with light SSW winds. Tomorrow will be a
warm and muggy day as high temperatures will be in the upper 80s
with dewpoints in the mid 60s.

Majority of the forecast area will remain dry tomorrow. However, 10-
15% PoPs remain for a round of showers across southern IN and along
the Ohio River during the afternoon hours. These showers would be
isolated and light as the moisture advection will be displaced to
the SW. Additionally, when assessing low-level sounding data a dry
airmass was still in place with little mid-level saturation. The
primary moisture is expected to be moved into the Ohio Valley by
Saturday afternoon and evening bringing PWATs between 1.5"-1.75".
Low temperatures for Saturday night will be in the upper 60s and low
70s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 317 PM EDT Fri Jun 5 2026

For the second half of the weekend into the early week period,
digging upper troughing across the Pacific NW will cause ridging to
build over the Great Lakes down into the Ohio Valley as the synoptic
pattern amplifies. The upper wave supporting a sfc cold front trying
to drop into the region from the north is expected to weaken and
eject east, with the cold front unlikely to make it through the area.

While amplifying upper-level ridging would normally support a drier
pattern, a closed low on the western flank of the ridge is expected
to travel slowly from the Plains across the Mississippi Valley
Sunday into early next week. This disturbance, combined with
anomalously high levels of saturation, should support elevated
chances for showers and thunderstorms, with the greatest rain
chances expected on Monday and Tuesday.

For Sunday, the main area of upper troughing and highest PW
anomalies should still be to the west of the region, with the most
likely position of the upper ridge axis centered over the area. As a
result, while there will be anomalously high moisture levels over
the region, isolated to scattered shower/storm coverage is expected.
It should be noted that a couple progs (notably the GFS and NAM)
feature a weaker upper ridge, allowing for greater low-to-mid level
SW flow and moisture return during the first half of the day on
Sunday. If this solution verifies, it would support a wetter
forecast on Sunday, so we`ll have to watch short range model trends
over the next 24-36 hours to see if the wetter or drier solution
becomes predominant.

Monday into Tuesday, the baggy upper shortwave is expected to slide
across the top of the ridge. Combined GEFS/Canadian/Euro ensemble
guidance brings an axis of exceptionally high PW (around the 99th
percentile, or 2") across the Ohio Valley, with the weakening in the
upper ridge providing some forcing for showers and storms. As
expected, sounding analysis shows deep saturation during this time
period, with high freezing levels and tall, skinny CAPE profiles
supporting efficient rainfall production. Given the expected limited
instability, severe storms appear unlikely, but heavy rainfall would
be a lingering threat, even with mean cloud layer winds on the order
of 15-20 knots. This is reflected in the WPC Excessive Rainfall
outlooks during the period.

As we head into Wednesday and the second half of the week, the upper
ridge is expected to become more dominant, with the shortwave that
brings better rain chances Monday-Tuesday ejecting into the NE
CONUS. This pattern shift should generally lead to lower
shower/storm chances and warming temperatures. At this time, the
Wednesday-Friday period is expected to feature low (10-20%) storm
chances, with highs in the upper 80s and low 90s, with dewpoints in
the low 70s evidence of steamy conditions. This could be the most
substantial period of heat so far this summer, especially since
higher dewpoints will lead to heat indices which could begin to
approach 100 degrees.

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 109 PM EDT Fri Jun 5 2026

VFR conditions will continue through the forecast period. High level
clouds will start to move in and stick around. Winds are currently
gusting to around 20kts from the SSW, but will then die down tonight
before picking back up tomorrow afternoon. There is a small chance
(10-20%) that HNB and SDF could see a light rain shower tomorrow
morning and afternoon. However, this was kept out of TAFs due to low
confidence in the available moisture in the low-levels.

&&

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

&&

$$

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