Spring Grove, Indiana Weather Forecast Discussion

355
FXUS61 KILN 051032
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
632 AM EDT Sun Oct 5 2025
.SYNOPSIS...
Warm and dry conditions continue through Monday morning. Rain
chances develop by Tuesday when a cold front moves through the Ohio
Valley. Cooler conditions arrive behind the front for the middle and
end of the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
A large anomalously strong upper level ridge centered over the east
coast will extend back into the Ohio Valley and will continue to
influence the weather today. Warm and dry conditions will persist.
Some patchy river valley fog is possible early this morning in
sheltered areas. Any fog that develops will improve quickly after
sunrise. Expect mostly sunny sky conditions with only few to
scattered diurnally driven cumulus clouds. Highs are generally
expected to reach the mid 80s.
&&
.SHORT TERM /MONDAY/...
Large mid and upper level will begin to be shunted east with a
southwesterly flow developing Monday. After mostly clear conditions
this evening expect to see an increase in clouds late tonight into
the southwest. Lows tonight to range from the mid 50s northeast to
the lower 60s southwest.
Moisture increases around the periphery of the ridge with H8 20-25kt
low level jet developing into the western counties Monday afternoon.
Most locations remain dry Monday but can not rule out a slight chance
of an afternoon shower - generally west of I-75. Warm conditions
continue with highs in the lower and middle 80s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
On Monday evening, surface high pressure and ridging will be located
off the east coast, with broad troughing across the northern plains
and western CONUS, and a general pattern of deep-layer southerly
flow from the southeastern CONUS into the Ohio Valley. By Tuesday
morning, widespread rainfall will develop, with a pronounced stream
of 925mb-850mb theta-e advection aimed into the Ohio Valley. While
instability is expected to be marginal, some pockets of convection
are expected to develop, although both instability and shear appear
quite marginal in terms of any concern for strong storms.
Precipitation is expected to come to an end late Tuesday night into
early Wednesday morning, as a cold front moves through the region
from north to south. Although the center of the surface high behind
the front will stay northeast of the ILN CWA, its influence will
bring subsidence and drier air, along with northeasterly flow. Highs
on Wednesday are expected to be in the mid 60s to around 70.
Confidence in forecast specifics becomes rather low confidence from
Thursday onward, as the upper flow pattern becomes ill-defined. It
is likely that temperatures will begin to rebound slightly from the
cooler conditions on Wednesday. The precipitation forecast will
depend on any additional disturbances developing upstream of the
area, with low confidence on when or if this will occur.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A large upper level ridge centered over the east coast will extend
back into the Ohio Valley and will continue to influence the weather
today. Mostly clear skies and light winds has led to river valley
fog early this morning. Have IFR vsby restrictions at KLUK and
possible MVFR restrictions at KILN. Any fog that develops will
improve quickly after sunrise. Expect only few to scattered diurnally
driven cumulus clouds. These diurnally driven clouds dissipate with
the loss of heating leading to clear skies this evening. Moisture
increases late tonight in the southerly flow with VFR ceilings
developing toward sunrise Monday.
OUTLOOK...MVFR ceilings and visibilities are possible on Tuesday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...Hatzos
AVIATION...AR

NWS ILN Office Area Forecast Discussion