529
FXUS61 KILN 131834
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
234 PM EDT Sat Jul 13 2024

.SYNOPSIS...
A few isolated showers, with perhaps a rumble of thunder or two,
will be possible today. Better chances for periodic showers and
storms may evolve Sunday and Monday before widespread storm
activity moves through the region Tuesday into Wednesday. Drier
and cooler conditions will return toward the end of the
workweek. However, very warm and humid conditions are expected
through the first part of the workweek.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Partly cloudy skies have evolved area-wide thanks to a fairly
healthy Cu field that continues to percolate about the area
this afternoon. Along with this will be the development of some
very isolated/disorganized SHRA, with perhaps a rumble of
thunder or two. Coverage and intensity of storms should be a
notch below what parts of the area have experienced over the
past few days owing to lack of forcing, lift, and shear. And as
such, most areas will stay dry through the near term period.

With coverage of clouds and SHRA a bit less widespread than in
past few days, temps have nudged a bit warmer -- a degree or two
either side of 90 for most spots. This, combined with dewpoints
in the mid to upper 60s will push heat index values into the
mid 90s by late afternoon.

Tranquil, but muggy, conditions are expected overnight
underneath mostly clear skies as lows dip into the upper 60s to
lower 70s. Some patchy river valley BR/FG may again be possible
in vulnerable locales.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
The focus of the short term period is going to be potential for
both storms and heat. Although there is some uncertainty
regarding both, especially in terms of specific timing and
location, there is a slightly stronger signal that has emerged
in some of the short-term guidance suggesting that a decaying
MCS will work its way into the nrn OH Vly after daybreak Sunday.
While the focus of this activity will initially be to the N of
the local area where the better forcing/shear will be
collocated, the MCS may lay out a thermally-induced boundary in
the nrn/wrn OH Vly into early Sunday afternoon. With some good
diurnally-driven instby expected to develop, it won`t take much
to initiate, or perhaps maintain, some convection stemming from
an MCS influence of some sort.

While the shear and forcing will be increasingly meager with
southward extent, a better pooling of richer LL moisture/instby
will be positioned to the SW of the best shear/forcing,
suggesting redevelopment in some capacity on the SW flank of a
decaying MCS and/or boundary as we progress into Sunday
afternoon. With the activity largely cold-pool driven, this
suggests that ISO/SCT convection may redevelop (initially off to
the W/NW of the ILN FA) before progressing to the E/SE through
the local area during the heart of the afternoon/early evening.
As with any convection that is largely driven from mesoscale
boundary positioning/interactions, there are uncertainties
regarding coverage/location/timing with pretty much all of the
specifics. But... from an ingredients perspective, there will be
the potential for ISO/SCT storms posing a gusty wind threat for
many spots near/N of the OH Rvr and especially near/N of I-71
into the afternoon. Some isolated damaging wind will be possible
with any of this activity given the 1500-2000 J/kg MLCAPE,
steep LL lapse rates, and favorable DCAPE environment.

The other aspect of the weather Sunday, one that should not be
overlooked, will be the combination of heat and humidity that will
lead to the potential for some heat index values around 100
degrees across central and southern portions of the region on
Sunday. This may be more widespread if storm activity is more
isolated and/or delayed than current forecasts. However, given
the prospect of storms/convectively-driven cloud cover,
confidence was not yet high enough to issue a Heat Advisory.

The setup on Sunday night offers its own set of challenges as
well as there are indications for another S/W to move to the
ESE through the nrn OH Vly, with westerly midlevel flow
developing to its W/SW, suggesting a backbuilding convective
setup somewhere near/N of the I-70 corridor. Of course, the
convection evolution and environment augmentation that occurs
during the daytime period will undoubtedly play a role in
exactly where storm activity may redevelop/persist during the
nighttime hours. For now, have maintained a chance PoP near/N of
I-70 to account for this potential.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Summertime pattern continues to start the extended period. Weak mid-
level ridging will likely build east into the Ohio Valley Monday
into early Tuesday. Can`t rule out an isolated storm or two Monday
with low-level moisture and persistent instability, however the
primary weather story during this time will be increasing heat under
the ridge. Blended guidance shows max heat indices from 100 to 105
degrees Monday and near 100 degrees on Tuesday.

By later on Tuesday, digging shortwave energy will cause a cold
front to sag southeast into the Ohio Valley late in the day. Showers
and storms will increase in coverage ahead of this feature Tuesday
afternoon and continue into Wednesday as the front moves through the
CWA. Cooler air arrives behind the front Wednesday and continues to
provide relief to the heat through the end of the week.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR conditions have evolved area-wide, with SCT/BKN VFR Cu
already draped across the region. While a stray brief SHRA
cannot be completely ruled out through sunset, coverage of any
activity should be limited/disorganized enough that will keep
fcsts dry at this point.

Skies should trend mostly clear after sunset, with perhaps a few
VFR Cu lingering about from time to time. Some VSBY reductions
are likely again late tonight at KLUK given light/stagnant
flow.

After 12z, focus will shift to one or more decaying clusters of
storms that will be approaching from the W/NW, likely
approaching the local area after 18z. The sites should remain
dry through 18z, but there is the expectation for at least ISO
SHRA/TSRA to overspread the area between 18z-00z, potentially
impacting the latter part of the KCVG 30-hr TAF.

Light WNW winds around 6-8kts will be maintained through sunset
before going light/VRB/calm overnight. WSW winds around
10-12kts, with gusts 15-20kts, are expected ahead of any ISO/SCT
SHRA/TSRA activity Sunday afternoon.

OUTLOOK...Thunderstorms possible at times Sunday through Wednesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...KC
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...
AVIATION...KC