Cottagegrove, Indiana Weather Forecast Discussion

856
FXUS61 KILN 221025
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
625 AM EDT Mon Sep 22 2025
.SYNOPSIS...
Periodic rain and storms are expected through at least midweek, with
daily opportunities for showers lingering into next weekend as well
as a very wet pattern becomes established in the region. Near to
slightly above normal temperatures are expected through the week,
even with more clouds than sunshine.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A few SHRA will be possible locally before a large complex of
SHRA/TSRA overspreads the local area from the W from mid morning and
beyond.
Large-scale ascent due to more robust jet dynamics will overspread
the area this morning into the afternoon amidst continued moisture
advection and PWs trending in excess 175% of seasonal norms. With an
uncapped environment and increasing deep-layer lift, a large complex
of SHRA/TSRA will begin overspreading the area by mid morning
through the afternoon, with a wet afternoon expected for most spots
locally. Some embedded thunder is expected with the activity,
although due to the poor midlevel and LL lapse rates, the overall
potential for severe storms appears to be somewhat meager. Coverage
of storms should be maximized during the afternoon through early
evening. Pockets of gusty winds will certainly be possible in the
strongest activity (especially if small linear/bowing segments are
able to develop (favored in N/NE KY and the lower Scioto Valley)),
but widespread /severe/ weather appears unlikely. Most locales will
simply receive some much-needed rainfall (with heavy downpours
leading to potential of an inch or more in some spots) along with
some rumbles from time-to-time. But the rainy/stormy day today will
certainly be a departure from the recent pattern of dry conditions
and ample sunshine.
Highs today top out in the mid 70s in WC OH to mid 80s in the lower
Scioto Valley and NE KY with expansive thick cloud cover and
widespread pcpn prevailing by midday just about everywhere.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
Widespread SHRA with embedded thunder will be ongoing across the area
locally this evening, but the bulk of the large complex will move off
to the E after sunset, with a trailing boundary back to the SW across
the srn third of the local area. S/W energy will still be lingering
back to the W of the local area in srn IN before moving into the ILN
FA overnight. The maintenance of better jet energy across the srn
part of the region should be enough to keep at least SCT activity
going across the Tri- State into N KY and even the srn Miami Valley
through midnight before decreasing in coverage late into the
overnight toward daybreak Tuesday. The activity tonight (which should
be focused near/S of the I-71 corridor) will be much slower moving
as the steering-layer flow gradually decreases, particularly N of
the OH Rvr. Additional heavy downpours will be possible in the
strongest activity.
There may be a bit of a lull in the coverage of SHRA with embedded
TS Tuesday morning into early afternoon, before daytime
redevelopment likely focuses near/E of the I-71 corridor into
central OH where the best lift will be maintained through the day.
However, the daytime Tuesday is looking drier than will be the case
today, even with ISO/SCT activity across the E/SE half of the local
area by mid/late afternoon.
Temps bottom out in the lower to mid 60s tonight before rebounding
to the upper 70s to around 80 by late Tuesday afternoon.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Positively tilted H5 trough remains stretched across much of the
central and eastern CONUS, which is the primary driver of the
unsettled weather pattern this week. Some scattered showers will
continue to develop Tuesday night as this southwesterly flow regime
ushers in a humid air mass, which is interacting with the upper
level energy.
Spotty showers persist into Wednesday, but the orientation of this
upper level trough modifies in which the mean trough axis becomes
more N-S facing. In this process, the upper low deepens and strong
PVA pivots through the Ohio Valley region. This increased forcing
will lead to a decent slug of widespread rainfall Wednesday night.
Numerous locations will observe at least 0.5", with some receiving
1" plus overnight.
Rain chances are expected to persist into Thursday and Friday as
this longwave trough remains slow to propagate eastward, but overall
QPF footprint will be much lower these days. By Friday, fewer
locations will actually observe measurable rainfall, but clouds
appear to hang around through most of the day, perhaps beginning to
break apart in the evening. The ILN CWA will finally be on the
western periphery of the trough axis, resulting in dry air
advection. If this pattern stays true, this will result in a mostly
dry forecast for next weekend.
Temperatures maintain the trend of staying near or just below
seasonal normals throughout the forecast period.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Any spotty SHRA through 15z should be spotty/disorganized, so
impacts should be brief at any one location, if at all. This being
said, there is the expectation for a large semi-cohesive band of SHRA
with embedded TS to overspread the local area from the W beyond 15z,
leading to prevailing widespread SHRA with embedded TS at each of
the sites for most of the afternoon through early evening.
The main item of interest with the pcpn this afternoon is the
likelihood for CIGs to go MVFR in the heaviest activity, with brief
MVFR VSBY also possible. While CIGs may briefly return to VFR after
the heaviest pcpn ends and the activity becomes more scattered in
nature, CIGs will trend back to MVFR/IFR area-wide by/after 06z.
SHRA may linger in parts of the area through the entirety of the
overnight, but activity should become more ISO in coverage toward
daybreak Tuesday. Some MVFR VSBYs may also develop late in the period
due to BR.
SW winds near 5kts will increase to around 10kts by mid-morning, with
brief higher gusts possible in the strongest storms. Winds will go
more southerly at 5kts or less late in the period once again.
OUTLOOK...Thunderstorms are possible through Thursday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...KC
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...Clark
AVIATION...KC

NWS ILN Office Area Forecast Discussion