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177
FXUS61 KILN 221409
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1009 AM EDT Sun Sep 22 2024

.SYNOPSIS...
An upper level disturbance moving through the Ohio Valley will
bring occasional chances for showers and a few thunderstorms
tonight through Tuesday. Warm conditions are expected again
today before more seasonable temperatures overspread the region
for the start of the work week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Mostly clear skies this morning will soon be replaced by
expansive cloud cover moving in from the W as a midlevel S/W
approaches this afternoon into this evening. The drier air
currently entrenched across the region will be shunted to the E
into the afternoon, with a fairly pronounced dewpoint gradient
expected to go along with it as some richer LL moisture advects
in from the W through the daytime. But it will take some effort
to truly moisten the profile, with an expectation that an
approaching band of SHRA, with embedded TS, will erode with
eastward extent. The SHRA may initially be falling from a deck
at about 8-10kft, with quite a bit of dry air to overcome in the
LL. This is shown well even on the typically more moisture-
robust guidance, with a rather deep layer of dry air in the
bottom 8-10kft to overcome, especially during the onset. So
while there will most certainly be some virga and perhaps some
sprinkles, the prospect of appreciable measurable rainfall drops
off rather abruptly near/E of I-75 through at least midday.

As we progress into early evening, enough saturation should
occur that coverage of SHRA, with even some TS, should
gradually increase toward sunset and beyond. But even then,
rainfall amounts should be rather light (<0.1") in most spots E
of I-75. The best chance for more appreciable rainfall will
likely be after sunset W of I-75 as broken clusters of SHRA/TSRA
attempt to move W before eroding again with eastward extent.

Highs should again reach into the lower 90s in central/south-
central OH and NE KY as the clouds and pcpn will be much more
delayed in these areas. Further to the W, expect temps to top
out in the mid to upper 80s.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
West to southwest flow will continue aloft tonight into Tuesday
with additional areas of mid level energy advecting across our
area. This will help drag a frontal boundary slowly east into
the region tonight and as we perhaps moisten up a bit more,
we should see a somewhat better chance for showers and few
thunderstorms to continue across the area tonight. Again
though, given the overall dry pattern, will continue to limit
pops to chance category for tonight. Lows tonight will be in the
low to mid 60s.

It looks like the frontal boundary may stall out across our area
through the day on Monday. With additional waves of mid level
energy moving through the Ohio Valley, a chance of showers and a
few thunderstorms will continue through the day. The best
chance for pcpn will be along and southeast of the boundary,
generally across our southern forecast area. Temperatures will
be more seasonable with highs on Monday ranging from the mid 70s
northwest to the lower 80s in the southeast.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Shortwave energy continues to dig into the Great Lakes and Ohio
Valley to start the extended period Monday night and Tuesday.
With an associated cold front just to our west, southwesterly
flow will provide deep moisture, allowing for a good chance of
widespread showers and storms. The latest guidance calls for a
wave of surface low pressure to lift toward the Ohio Valley late
Monday night, with showers increasing from southwest to
northeast by morning. The cold front will then make it way
through the area later on Tuesday. Guidance varies a bit, but
QPF amounts appear to average half inch to an inch during this
time.

The low moves away on Wednesday... at which time uncertainty in the
forecast increases significantly as a tropical system may be moving
into the southeast United States. In general, we appear to be headed
into more of a blocky pattern once again, with the northern stream
retreating well north into Canada. This would make rainfall in our
area depend upon the development and movement of the tropical system
late in the week. For now, have a low chance of PoPs to allow for
the uncertainty during this time.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
Fairly widespread river valley fog will slowly improve through
mid morning. This will likely result in some IFR to locally
VLIFR conditions at KLUK for the first hour or so of the TAF
period. Otherwise, expect high and mid level clouds to increase
through the day ahead of an approaching upper level
disturbance. This will eventually lead to a chance for showers
and a few thunderstorms late this afternoon into tonight.
However, given the dry airmass in place across the region,
there is some uncertainty as to how widespread these will
actually be. Will therefore just include a VCSH in the TAFs
heading into this evening. Cigs will drop into MVFR category
later tonight into Monday morning.

OUTLOOK...Thunderstorms possible Tuesday.

&&

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

&&

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