492
FXUS61 KILN 170549
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
149 AM EDT Sat Aug 17 2024

.SYNOPSIS...
An upper level low pressure system will shift slowly east
across the Great Lakes region through the weekend. This will
lead to occasional chances for showers and thunderstorms. High
pressure and a drier air mass will then build into the region
through the upcoming work week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Upper low continues to shift eastward, providing weak forcing to
maintain some of these showers into the early overnight before
dissipating. Once rain chances end tonight, some of the low
clouds will dissolve as well. A very saturated air mass remains
in place, which combined with the clearing skies and light
winds, patchy fog will become a possibility, especially near
the river valleys.

Mild overnight lows in the upper 60s to lower 70s are forecast.

&&

.SHORT TERM /SUNDAY/...
The mid-level low will continue to wobble slowly east causing
cyclonic/convergent low-level flow over the Ohio Valley on
Saturday. Plenty of morning sunshine along with lingering low-
level moisture will lead to SBCAPE above 2000J by the afternoon
hours, with the highest values likely southeast of Interstate
71 along the axis of deepest moisture. While effective bulk
shear will not be that impressive, we should see some pretty
tall cores due to the increase in forcing and instability.
Therefore, we will need to watch for scattered storms containing
borderline hail and damaging wind gusts.

The focus of the convection will continue to move off to the
east Saturday night, leading to quieter conditions returning
late. Decreasing clouds allow temperatures to cool into the
lower to middle 60s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A somewhat anomalous weather pattern will be established for the
beginning of the long term period as a mid/upper level low/trof
deepens/digs into the ern Great Lakes/OH Vly region, yielding
broad/deep-layer cyclonic flow in the region and fairly impressive
negative height anomalies to go along with it. This will translate
to a rather unsettled pattern locally Sunday and again early Monday
as the combination of typical diurnally-driven summertime heating
and LL moisture coinciding with cooler temps aloft will generate
numerous SHRA, with perhaps a rumble of thunder, during the
afternoon into early evening Sunday.

Daytime highs will be quite a bit cooler on Sunday, owing to
extensive/expansive cloud cover and numerous afternoon SHRA
pinwheeling around the low center just to the NE of the ILN FA.
Temps should top out in the mid 70s to around 80 degrees, with
likely to categorical PoPs from SW to NE, respectively, across the
local area for the afternoon time period. Sunday will likely be one
of those days where it rains on-and-off several times in any one
location over the course of the daytime, but perhaps not amounting
to more than a third to half of an inch in total.

The potential for showers will persist into Monday morning near/SE
of I-71 as the main trof axis /finally/ pivots through the area,
yielding increasingly dry/clear conditions into the afternoon hours
from NW to SE. A /very/ dry airmass will filter into the region late
Monday and likely settle into the OH Vly through the entirety of
next workweek, allowing for dry and seasonably mild conditions for
at least the first half of next workweek. In fact, there are
indications for several overnights where temperatures will likely
dip into the lower 50s, or even upper 40s in some
rural/sheltered/low-lying locales. This would especially be the case
Tue/Wed/Thu AMs.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A line of showers and thunderstorms moving across central
Indiana this morning will continue to push east toward our area
over the next couple of hours. This is moving into a less
favorable environment, so expect to see an overall weakening
trend with these storms. Nonetheless, suppose they could hold
together into at least northwest portions of our area, so will
allow for a couple hour period of a VCSH at KDAY to account for
this. Elsewhere across our area, some MVFR br has been
developing, with some IFR to LIFR vsby restrictions in some of
the river valleys. This will persist through daybreak before
the vsbys begin to improve.

Otherwise, expect scattered showers and thunderstorms to become
more numerous as we destabilize this afternoon. Locally heavy
rainfall and brief IFR vsbys will be possible with the
afternoon storms. This activity will taper off as we head into
this evening with partial clearing developing. However, some
MVFR to IFR  cigs and perhaps some areas of MVFR br will
develop late tonight into early Sunday morning.

OUTLOOK...Thunderstorms possible on Sunday.

&&

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

&&

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