017
FXUS63 KLMK 190747
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
347 AM EDT Sun Jul 19 2026

.KEY MESSAGES...

* Today isolated to scattered showers and thunderstorms will bring
  heavy rainfall, lightning, and gusty winds to central Kentucky.

* Confidence in severe storms for damaging winds and a possible
  tornado is increasing Tuesday afternoon. Heat indices will be in
  the 100-110 degree range as well.

* Calm weather moves in with cooler than average highs for Wednesday
  through Friday this week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 346 AM EDT Sun Jul 19 2026

An upper ridge covers the western three quarters of the CONUS with
an upper trough centered over the Northeast. Underneath northwest
flow, surface high pressure sits over the Midwest and western Great
Lakes north of the cold front that sits just north of the Ohio
River. Throughout the day, the front will continue working south
through central Kentucky. South of the front, precipitable water
values remain high, climbing to around 2.25". North of the front,
values drop to near 1.25" and continue to fall to near around 1"
across central Indiana.

As temperatures warm into the mid 80s and low 90s for highs, MLCAPE
values are expected to climb to 2,000 to 2,500 J/kg south of the
front. This will help more isolated to scattered showers and
thunderstorms to develop from diurnal warming. Light northwest flow
will push convection to the southeast slowly. High PWATs and slow
moving storms could lead to flooding concerns, but believe most of
the activity will remain scattered and transient enough to limit the
flooding threat.

Tonight, as we lose diurnal warming, showers and thunderstorms
become more isolated and begin to dissipate. The weak front will
likely remain over part of central Kentucky with high pressure to our
northeast and an upper ridge to our west. Precipitable water values
are expected to drop slightly to just under 2" south of the front,
but we don`t have anything moving through to dry the region. Winds
will ease to near calm with partly clear skies, leading to patchy
fog over southern Kentucky as temperatures drop into the mid 60s to
low 70s over the CWA.
.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 346 AM EDT Sun Jul 19 2026

===== Monday - Saturday =====

The dividing line between higher dewpoints and scattered convection
won`t move much from the stalled out sfc boundary Monday afternoon.
Generally from the Ohio County to Casey County, KY area, scattered
pulse storms are expected with area-wide highs in the upper 80s to
low 90s. Could have a pop up storm across the north but any storm
along and north of the Ohio River will be isolated in coverage.
Heavy downpours, lightning and sub-severe wind gusts will accompany
any storm, with rainfall totals across the southern CWA generally
remaining under 0.25", with locally higher amounts. The signal isn`t
strong, but any lingering convection from the Wisconsin/northern IL
area will push south towards areas of higher CAPE, and could bring a
round of overnight rain into the CWA overnight Monday and early
Tuesday morning. These storms haven`t formed yet so this bears
watching but with any overnight storms, no severe threat is expected
beyond heavy downpours and lightning.

Tuesday morning, if there aren`t the conditional line of morning
storms, we`ll probably have morning cirrus with mostly clear skies
throughout the afternoon. During the day, a low pressure swinging
through the Great Lakes region will usher in a strong mid level jet
of at least 40-50 kts into the Ohio Valley. Both speed and
directional shear from a backing wind profile will be present along
with MLCAPE near or greater than 2,000-3,000 J/kg from latest LREF
guidance. Along with long and curved model hodographs, there is
increasing potential for severe weather including damaging winds and
a possible tornado. Any severe weather would be from a main line of
storms moving through the Ohio Valley along a cold front Tuesday
afternoon and into the evening hours as the line of storms pushes
south through central KY towards the TN border. For now, have a plan
ready making sure you have multiple ways to receive weather alerts
and have a safe place to take cover in your home in case a tornado
occurs. There is still a bit of uncertainty with timing and severity
of these storms, though this set up supports the severe weather
types already mentioned. The SPC has issued an Enhanced Risk for
severe weather Tuesday afternoon, with a 45% of occurrence from
damaging winds and tornadoes being issued as well. Definitely an
unusual pattern for this time of year from such a strong mid level
jet in the middle of summer. Highs on Tuesday will be in the low 90s
with heat indices ranging 100-110 degrees. A heat advisory may be
needed for the afternoon before the severe storms roll through.

Beyond Tuesday, surface high pressure builds in with a predominant
NW flow at higher levels bringing in cooler and drier air for
Wednesday through Friday. Highs will be in the low 80s with the
coolest day being Thursday. Some places may not reach 80 degrees at
all in the afternoon then. Eventually, by Friday afternoon and into
Saturday, SW flow on the backside of the surface high returns with
seemingly typical afternoon convection on Saturday afternoon, highs
reaching the upper 80s and low 90s once again.

&&

.AVIATION /06Z TAFS THROUGH 12Z MONDAY/...
Issued at 231 AM EDT Sun Jul 19 2026

South of a cold front over southern Indiana. Isolated to scattered
showers and thunderstorms continue to develop and slide southeast.
Area TAF sites will spend most of their time dry and not being
impacted. Even if a storm was to hit an airfield, it should quickly
pass. The best chances for impacts currently remain at HNB and later
in the period these chances will shift towards BWG as the front
sinks south. SDF, LEX, and RGA are in better shape to miss most of
the activity over the next several hours. Later this morning, an
area of MVFR with limited IFR ceilings are expected to drop south
out of Indiana into central Kentucky. This is expected to impact
HNB, LEX, and RGA.

&&

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

&&

$$

SHORT TERM...KDW
LONG TERM...BKF
AVIATION...KDW