397
FXUS61 KILN 050731
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
331 AM EDT Sun May 5 2024

.SYNOPSIS...
A warm and moist airmass will remain in place across the region
into the middle part of next week, leading to occasional
periods of showers and thunderstorms into Thursday. Slightly
cooler and drier air will return by the end of the week,
although rain chances may persist at times into next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A weak cold front will be approaching the area from the north early
this morning. Ahead the front, clouds remain in place with generally
warm, muggy, and calm conditions persisting. Some pockets of mist
and reduced visibilities are possible before sunrise due to excess
moisture in place in the stagnant environment.

As the cold front moves through the area later this morning, only a
slight chance for showers and thunderstorms is forecast for the
morning hours due to lack of instability. Showers/storm chances then
increase in the afternoon along and southeast of I-71 where
instability is forecast to form ahead of the progressing front in
response to diurnal heating. There is some hint of stronger deep
layer shear and instability overlapping near the Columbus metro in
the afternoon, as represented by SPC marginal risk, so an isolated
strong wind gust cannot be ruled out. Forecast highs are generally
in the upper 70s to near 80.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
An area of high pressure will be moving across the Great Lakes on
Sunday night while zonal upper level flow persists. South of the
high, a cold front is expected to be sinking southward into the Ohio
Valley. The frontal boundary is forecast to reach near the Ohio
River before stalling late overnight into the early morning hours.
Rain chances should remain fairly low overnight and confined to the
warm sector south of the cold front. Winds shift to the north behind
the front. Lows drop into the 50s north of the front while remaining
the the lower 60s south of the front.

The surface high remains to the north of the Ohio Valley on Monday
which helps keep the stalled front near or just north of the Ohio
River through the day. A fairly strong dew point gradient and small
temperature gradient should be observed by the afternoon. Areas
south of the front should have dew points rising into the 60s while
areas north of the boundary have forecast dew points remaining in
the 50s. Shower and thunderstorm chances remain mostly confined to
areas in southern Ohio and northern Kentucky in the afternoon where
some instability may develop overlapping the best moisture. Very
isolated locally heavy downpours in slowly moving shower/storms
could develop.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Broad upper level troughing over the western two thirds of the
CONUS will shift slowly east through mid week, keeping the Ohio
Valley in persistent west to southwest flow aloft. This will allow
for a series of embedded mid level short waves to move through the
region Tuesday through Thursday. At the surface, a frontal boundary
along the Ohio River will lift north across the area through the day
on Tuesday with afternoon highs climbing into the upper 70s to lower
80s. This will combine with surface dewpoints in the mid 60s to
produce surface based capes into the 1500-2000 J/kg range. This will
result in fairly widespread shower and thunderstorm development
Tuesday into Tuesday evening and with strong deep layer shear
develop through the day, some severe storms can be expected.

A trailing cold front will push southeast across our area Tuesday
night before stalling out heading into Wednesday morning. There is
then some uncertainty as to how far back to the north the front will
lift through the day on Wednesday ahead of an approaching low
pressure system. Along and south of the boundary, good instability
will develop with fairly widespread showers and thunderstorms
possible once again. With strong deep layer shear persisting and the
approach of a surface low, severe storms will again be possible.
Highs on Wednesday will be in the upper 70s to lower 80s.

A cold front will then push off to our southeast later Wednesday
night into Thursday, leading to lower pcpn chances and slightly
cooler temperatures. Highs on Thursday will be in the mid to upper
70s. Additional short wave energy dropping down across the Great
Lakes will help deepen the trough over the Great Lakes and Ohio
Valley Friday through Sunday. This will keep us in a cooler airmass
with daytime highs in the 60s to lower 70s. This will also keep some
lingering lower end chances for showers and a few thunderstorms
through the weekend.


&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Showers and thunderstorms likely will continue to diminish in
coverage early this morning despite the brief surge in activity in
the past hour. Otherwise, stagnant and moist conditions have
been left in the wake of earlier convection which could result
in BR forming later tonight before sunrise. MVFR ceilings are
also forecast to develop later tonight thanks to abundant low
level moisture ahead of an approaching front. Although BR should
mix out shortly after sunrise, MVFR ceilings may linger until
around 1800z before scattering and lifting. After 1800z, VFR
ceilings are expected and the best chances for showers/storms
are limited to the Columbus sites during the afternoon. MVFR
conditions may redevelop after 0600z Monday.

Winds remain light and variable across the sites tonight. Westerly
winds increase to around 10 knots after 1200z with a front moving
through the area. Winds are expected to take on more of a northerly
component after 0000z behind the front.

OUTLOOK...Thunderstorms are possible at times each day through
Thursday. MVFR conditions are possible Monday morning and
Tuesday morning.

&&

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

&&

$$
SYNOPSIS...Campbell
NEAR TERM...Campbell
SHORT TERM...Campbell
LONG TERM...JGL
AVIATION...Campbell