134
FXUS61 KILN 141713
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
113 PM EDT Wed Aug 14 2024

.SYNOPSIS...
Surface high pressure will drift to the east of the region
tonight, with a more humid airmass set to filter into the area
by late Thursday through Friday. Showers are storms are expected
at times late Thursday night through Friday evening, with some
scattered showers and storms lingering into the weekend as
well. Near normal temperatures will prevail through Friday
before slightly cooler air returns this weekend through the
first half of next workweek. Drier conditions return for Monday
and beyond.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A picturesque day continues as abundant sunshine, with a few
fair-weather Cu, and seasonably mild temperatures persist
region-wide. Negative PWAT anomalies will remain entrenched
across the region through tonight, translating to tranquil and
pleasant conditions locally. Temps this afternoon will top out
in the mid to upper 80s, with dewpoints generally in the mid to
upper 50s.

A midlevel ridge axis will traverse the region through late tonight
as it slowly flattens out. Rounding the peak of this ridge will
be some mid/upper level moisture, which should thin to some
degree as it attempt to impinge on the slowly-retreating ridge
axis. So even though dry conditions will persist through
tonight, some mid/high level clouds will be on the increase from
the W late, especially toward daybreak and beyond. Temps
tonight will be a few degrees warmer than previous nights, owing
to patchy mid/high clouds.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
The ridge axis retreats and flattens with eastward extent into
the day Thursday as a S/W progresses E through the OH Vly and
into the local area into the afternoon. This will provide a
substantial increase in mid/high clouds, although the lower part
of the profile should still remain fairly dry. This thicker
layer of antecedent dry air will erode the pcpn shield with
eastward extent, inhibiting much in the way of widespread
measurable pcpn through the afternoon. Certainly a few sprinkles
or very light SHRA will be possible into mid afternoon,
especially near/W of I-75. But most spots remain dry through the
afternoon as temps top out generally in the lower (near/W of
I-75) to upper (south-central OH/NE KY) 80s.

More robust moisture/theta-e advection will be underway as we
progress into Thursday night, but the best pooling of LL (SB)
instby will likely stay to the W/SW of the immediate local area.
Better broad-scale forcing will arrive late Thursday night as
the trof axis digs into the mid MS Rvr Vly, promoting a bit more
widespread shower/storm activity across at least a part of the
region. While the best coverage of activity will be focused
where the best instby resides (srn IL/srn IN/wrn KY), some
elevated convection should still spread E into the local area by
the predawn hours toward daybreak Friday even as the LL
environment remains quite stable. Although there are questions
regarding how much thunder will be present in this setup early
Friday morning, it is during this stretch that the highest PoPs
are likely to be focused. Still yet, there are indications that
ern parts of the local area may remain completely dry through
the entirety of the short term period.

Lows Thursday night dip into the upper 60s and lower 70s amidst
a notably more humid airmass.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A broad mid-level trough will be moving east across the
northern tier of states, reaching the upper Midwest by 12Z
Friday morning. On the southern periphery of this broad trough,
forcing will be on the increase over the Ohio Valley, as a
result of some shortwaves rotating around the base of the
trough. Attention will then turn to the potential for
additional convective development on Friday afternoon. The
potential strength of these storms will be dependent on several
factors, including the degree of contamination from the morning
precipitation. Model soundings suggest the atmosphere will
destabilize, though the degree is unclear, especially as there
are differences in the handling of lapse rates (particularly
mid-level lapse rates). There does appear to be some broad
forcing for ascent as a result of the trough, as well as some
renewed 925mb-850mb theta-e advection during the afternoon. Wind
shear appears sufficient for some degree of storm organization,
and precipitable water values will be approaching two inches.
Though uncertainty remains, this setup does support at least
some lower-end risk for severe weather and heavy rainfall.
Specific timing details and thermodynamic profiles will be the
main questions, and uncertainty on those factors precludes a
greater concern as of now.

Models are coming into somewhat better agreement on the progression
of the trough over the weekend. It will be moving slowly, but may
only briefly develop into a closed low before it continues moving
east. The Ohio Valley will be on its southern periphery, in a regime
of generally westerly flow -- with chances for precipitation
continuing. PoPs will be kept in the forecast each day from Saturday
through Monday, but with gradually diminishing chances from one day
to the next due to temporal forecast uncertainty and the fact that
stronger forcing will likely be displaced to the north and east with
time.

Temperatures in the middle to upper 80s are expected Friday, with
cooler values in the lower to mid 80s over the weekend and into next
week.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
FEW/SCT VFR Cu are expected until sunset with a few cirrus
beginning to filter in from the W past 00z. Mid/high cloud cover
will be on the increase from the W toward daybreak and beyond,
with perhaps a few sprinkles possible at KCVG/KLUK/KDAY by
mid/late morning. However, most of the area is expected to
remain dry through the period, with VFR conditions prevailing,
aside from some MVFR river valley BR at KLUK between 06z-12z.

Light NE winds around 6-8kts will go more easterly tonight at
5kts or less before going southerly at 5-10kts once again by 18z
Thursday.

OUTLOOK...Thunderstorms are possible Friday.

&&

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

&&

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