Flash Flood Warning 62, NWS Louisville, KY

Area Forecast Discussion
National Weather Service Louisville KY
413 AM EDT Sat Jun 27 2026

.KEY MESSAGES...

* The risk for heavy rainfall and flash flooding continues today
  across southern IN and central KY. Rainfall amounts of 1 to 3
  inches are possible, with locally higher amounts due to training
  storms. Isolated significant flash flooding is possible.

* Summer heat and humidity build across the region next week, with
  triple digit heat indices likely (70-90% chance) west of I-65 on
  Monday and area-wide Tuesday through at least Friday. This will
  pose a risk for heat-related illness, especially among vulnerable
  populations.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 413 AM EDT Sat Jun 27 2026

A significant rainfall and flash flooding event is in progress
across southern Indiana, and the heavy rainfall threat is set to
shift southward later today. Early this morning, scattered storms
producing highly efficient rainfall are moving west to east across
southern IN and north-central KY. A 25-30 kt WSW low-level jet
continues to funnel moisture up the Lower OH River Valley. PW values
approaching 2.2 inches and deep warm cloud depths are supporting
more tropical rainfall processes. New Flash Flood Warnings are in
effect for Dubois, Perry, Crawford, and Meade counties, and
additional warnings are possible downstream (including in the
Louisville Metro).

By 7-11 AM EDT this morning, convective clusters are forecast to
have congealed more over central KY ahead of a convectively-
generated wave/MCV. The 25 kt westerly LLJ weakens slightly and
shifts ever so slightly south over central KY during the late
morning and early afternoon hours. This trend continues, with the 25-
30 kt LLJ responding across south-central KY this evening in the
left exit region of a 40 kt mid-level jet over TN. This should give
southern IN a brief respite, with swaths of heavier rainfall
shifting into central and southern KY from mid-morning into early
afternoon.

Scattered showers and storms will remain possible in southern KY
into the evening hours. However, the lull in the action along and
north of I-64 will allow the northern areas to destabilize during
peak heating. Scattered convective redevelopment appears likely
across southern IN and northern KY by early to mid-afternoon. The
still moist environment will still support locally heavy rainfall,
so we have extended the Flood Watch for areas along and north of I-
64 through 8 PM EDT this evening. The Flood Watch for areas south of
I-64 continues through 8 AM EDT Sunday.

Additional rainfall amounts of 1-3 inches appear possible early this
morning through Sunday. Localized higher totals of 3-5 inches will
be possible across south-central KY today into tonight. In addition
to heavy rainfall today, some stronger storms will be capable of
locally strong wind gusts. We do see a modest increase in low-level
SRH this evening across southern KY, but overall the tornado threat
is fairly low.

Overnight into early Sunday, shower and thunderstorm coverage should
decrease over much of the area with the highest PoPs consolidating
in a NW to SE oriented warm advection wing over western and south-
central KY. Mid and upper level ridging amplifies over the MS Valley
on Sunday, and increasing subsidence aloft will lessen precipitation
chances and coverage. However, at least isolated showers and storms
will remain possible into Sunday afternoon. Highs in the low 80s
will be common today, with temperatures rising into the mid 80s to
near 90 on Sunday.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 413 AM EDT Sat Jun 27 2026

A dramatic pattern change is still expected next week. Models
suggest substantial amplification of an upper level ridge over the
eastern CONUS. We expect to transition to a stretch of hot and
oppressively humid conditions. For those currently experiencing
flooding, it will be a notably drier stretch. Afternoon high
temperatures are forecast to reach the low to mid 90s. With
lingering humidity (sfc dewpoints in the mid 70s, heat indices of
100-110+ are likely each day.

Strong ridging aloft should keep us mostly dry through Thursday,
though there is a 10% chance for isolated pulse convection by
Thursday. There are signals the ridge may weaken somewhat heading
into next weekend. Hot and humid conditions are likely to linger
into the Fourth of July holiday, but we have a 30-40% chance for
showers and storms on Friday and Saturday.

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 135 AM EDT Sat Jun 27 2026

Multiple waves of showers and storms are moving west to east across
Kentucky and southern Indiana early Saturday morning. These will
bring occasional visibility drops and perhaps (40% chance)
lightning strikes to the airfields - both are captured in PROB30
groups. The area should have a moment of repose early this
afternoon, though MVFR ceilings may linger. Another round of
showers and thunderstorms is forecast to develop during the late
afternoon and linger through the evening. Confidence is highest
in this second wave at BWG where another PROB30 group was
added, but there is a low (20-30%) chance at the other terminals
as well. Winds will be light and fickle early this morning,
then become predominantly southwesterly at 8-12kt by around
15z/11am EDT.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Flood Watch through this evening for KYZ030>043-049.
     Flood Watch through Sunday morning for KYZ023>029-045>048-
     053>057-061>067-070>078-081-082.
IN...Flood Watch through this evening for INZ076>079-083-084-
     089>092.

&&

SHORT TERM...EBW
LONG TERM...EBW
AVIATION...JRB