078
FXUS61 KILN 121419
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1019 AM EDT Mon Aug 12 2024

.SYNOPSIS...
A weak upper level disturbance will offer an increase in clouds
this afternoon and a chance of a light shower or sprinkle tonight.
Otherwise, high pressure will remain across the region through
the middle of the week offering dry weather through Wednesday.
Chances for showers and thunderstorms develop Thursday into
Friday as a frontal system approaches from the west.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Satellite trends and latest guidance suggests that clouds may be
a little slower to increase this afternoon. So adjusted the sky
cover along those lines. Otherwise, little change to previous
forecast.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
Surface high will remain across the region through the period.
A weak mid level short wave to track southeast across the area
tonight. Mid levels moisten up but low levels remain relatively
dry. Based on model trends have added a slight chance of a light
rain shower or sprinkle across the the southern counties
tonight. With clouds tonight, lows will be warmer with readings
in the upper 50s and lower 60s.

Northwest flow with another weak shortwave dropping thru the
area Tuesday. Dry airmass in place but this feature could offer
a few sprinkles or a light rain shower across the north-
northeast counties Tuesday afternoon. At this time have allowed
for an increase in clouds but maintained a dry forecast. This
may require a change if forecast solutions more aggressive and
confidence increases. Temperatures warm closer to normal with
highs in the lower and middle 80s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
On Tuesday evening, a broad northwesterly flow pattern aloft will be
in place over the Ohio Valley. The surface pressure pattern will be
somewhat nebulous, with a broad area of high pressure centered off
to the north over the Great Lakes, but only very weak flow on its
southern periphery for the ILN CWA. The air mass will remain fairly
stagnant through Thursday, with highs on Wednesday in the 80s, very
close to normal values for mid-August.

By later Thursday and into Friday, the upper pattern will become a
little more amplified. There is high confidence among models that
there will be troughing over the northeastern CONUS, and a narrow
wedge of ridging extending from the Gulf coast through the Ohio
Valley. There is a considerable amount of model spread regarding the
evolution of another trough off to the west, initially over the
central plains on Thursday -- then progressing east from there.

PoPs will be gradually brought into the area from west to east on
Thursday. Although surface flow will remain out of the southeast,
flow at 850mb and above will be shifting to the southwest, with a
surge of theta-e moving into the area. A more pronounced change to
the setup is expected for Friday, as mid-level troughing aids ascent
over the region, with deep-layer southwesterly flow bringing a
notable increase in boundary layer moisture -- although temperatures
may remain similar due to increased clouds and precipitation. Friday
will thus have the greatest PoPs through the extended forecast
period -- kept at about 50 percent for now, but with the potential
for this to increase as the forecast event gets closer in time.
Precipitation chances and details are less certain for Saturday and
Sunday, with model uncertainty regarding the position and magnitude
of the trough -- which could even develop into a closed low
somewhere north of the Ohio Valley.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
West-northwest flow aloft with surface high pressure building
into the area. Expect only some scattered high level clouds
this morning. Some brief patchy river valley fog may result in
MVFR vsby restrictions at KLUK around sunrise. Otherwise, a mid
level disturbance will move through the Ohio Valley this
afternoon into tonight. This will lead to an increase in mainly
mid level clouds and perhaps a few light showers or sprinkles
tonight. Coverage is too low to mention in the TAF forecast at
this time.

OUTLOOK...No significant weather expected.

&&

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

&&

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