428
FXUS61 KILN 250619
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
219 AM EDT Wed Sep 25 2024

.SYNOPSIS...
A wave of low pressure will lift north into the Great Lakes
with a weak, slow moving front stalling out over the region
overnight into Wednesday. Thunderstorms will decrease with a
threat for a few showers continuing overnight into Wednesday.
An upper level low and remnants of Tropical Cyclone Helene will
then provide chances of rainfall through for the end of the week
and into the weekend.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
Scattered thunderstorm developed across the area this afternoon
in the moderately unstable airmass ahead of a weak front
pushing in from the west. Loss of heating and instability has
led to a decrease in storm coverage and intensity.

This thunderstorm and shower activity will continue to decrease
in coverage with a few remnant showers remaining possible overnight.

During the overnight hours, low level clouds are forecast to
develop, as well as some patchy fog.

Expect lows from near 60 in outlying areas to the mid 60s in
the urban locations.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 AM THURSDAY/...
Quite the complex upper level pattern throughout the short term
and then eventually the long term periods with an elongated
trough stretching southward from Canada all the way to the lower
Mississippi Valley. A closed low in the middle Mississippi
Valley provides constant mid and upper level moisture advection
as it stalls Wednesday night. While overall rainfall amounts are
expected to be light, there is a long duration of shower or
light rain chances throughout the entire day, especially east of
the I-75 corridor.

A weak surface boundary moving slowly southeastward into
eastern Indiana and western Ohio may spark a few showers into
the area during the afternoon, but the boundary will dissolve as
high pressure builds in across the lower Midwest Wednesday
evening.

By late Wednesday night, the combination of the now cut-off upper
level low and Tropical Cyclone Helene results in a pressure
pattern where a weak high pressure is positioned across the
Great Lakes and Midwest with the low pressure to the south.
Upper level diffluent flow still persists over southeast
portions of the area primarily along and south of the I-71
corridor. As a result, mentions for rain persist, but overall
rainfall amounts remain light.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Our region will be wedged between two mid level closed lows on
Thursday. One will be spinning over the lower Mississippi River
Valley while the other low will be pivoting east across
southeast Canada and New England. Clouds and a chance of showers
will persist, with the highest PoPs along and south of the Ohio
River. Highs will range from the mid 70s to the lower 80s.

The track of Helene is coming into better focus, which it has
now shifted more east into the middle Ohio Valley than the
previous track which was more west into Missouri. That brings
the remnants across our area Thursday night into Friday, with
the system weakening and becoming absorbed into the mid level
closed low to our southwest Friday night. This should bring a
good chance of needed rain to our drought stricken region.
Temperatures will be warm at night, in the 60s, with highs on
Friday in the mid 70s to the lower 80s. Winds will be gusty on
Friday, 25 mph to 25 mph due to a tightening pressure gradient.

For the upcoming weekend, a chance of showers/slight chance of
thunderstorms, will continue as the center of the mid level
closed low slowly meanders east across the Ohio Valley.
Temperatures will be persistent, lows in the 60s, and highs in
the mid 70s to the lower 80s.

The mid level closed low is forecast to be pushed east by
Monday/Tuesday as another large scale mid level trough digs
southeast into the Great Lakes. Chance of rain will be lower as
the first low moves away. Temperatures will cool some. Lows in
the upper 50s to the lower 60s will be followed by highs in the
lower to mid 70s.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
No doubt a difficult forecast for the first 6 hours of the TAF
period, with patchy river valley fog along with developing low
stratus. Rain during the day has provided cool, humid low levels
that will likely produce IFR stratus through the night. Timing
out the formation of the stratus leaves plenty of uncertainty.
Have stayed with previous TAF`s timing as a starting point and
will adjust as the trends allow.

IFR/MVFR ceilings will slowly improve lift this morning leading
to a mostly cloudy day. Can`t rule out a few showers this
afternoon at the southern terminals near Cincinnati due to a
stalled frontal system.

OUTLOOK...MVFR ceilings possible Wednesday night. Wind gusts
between 30 to 35 mph possible Friday.

&&

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

&&

$$
SYNOPSIS...McGinnis/AR
NEAR TERM...BPP
SHORT TERM...McGinnis/AR
LONG TERM...Hickman
AVIATION...