252
FXUS61 KILN 132346
AFDILN

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

.SYNOPSIS...
Showers and storms may develop both 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/...
Persistent showers in central Ohio appear to finally be
diminishing. Expect this trend to continue into the early
evening.

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 /23Z SATURDAY THROUGH THURSDAY/...
Showers in the vicinity of the Columbus terminals will diminish
very early in the period with associated cumulus following soon
thereafter. Expect some visibility restrictions in fog to
develop at KLUK again, although it is unclear whether
visibilities will be as low as last night. Some BR is also
possible at KILN. Heading into Sunday, expect high-based cumulus
to develop with the potential for thunderstorms in at least part
of the area late in the period.

OUTLOOK...Thunderstorms possible from late Tuesday into Wednesday.

&&

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

&&

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