388
FXUS61 KILN 080200
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
900 PM EST Fri Feb 7 2025

.SYNOPSIS...
Surface high pressure over the CWA will move east this evening.
A low pressure center will cross northeast and generally follow
the Ohio River on Saturday, bringing a shot of rain to the area
that may begin as a rain/freezing rain mix in the morning. The
low will quickly move east by evening, and high pressure
behind it will usher in colder air on northwest winds.

&&

.NEAR TERM /THROUGH SATURDAY/...
A surge of 850mb-700mb theta-e is moving northeast into the ILN
forecast area, and as of this writing (9PM) the first radar
echoes are currently entering the far southwestern CWA.
Observations in this area (SWON/CRRL sites on the Kentucky
Mesonet) show temperatures in the upper 30s to lower 40s, but
with dewpoints in the lower 20s -- suggesting there will be the
potential for temperatures to fall due to evaporative cooling
once the rain begins. For areas where temperatures are currently
in the lower to mid 30s, a fall of a couple degrees could be
enough to produce a brief period of freezing rain near the onset
of precipitation. This seems most likely along a line from
Franklin County IN through Pike County OH, perhaps buffered by a
county to the north and south of that line, and primarily in the
07Z-13Z time frame. After that, a more rapid warming in
temperatures will likely bring much of the freezing rain
potential to an end. Some additional freezing rain is possible
tomorrow afternoon in the far northern forecast area
(Mercer/Auglaize/Hardin counties in Ohio).

With precipitation amounts expected to be light, confidence is
not high enough to issue an advisory for the overnight freezing
rain potential. A Special Weather Statement will be issued for a
portion of the forecast area.

&&

.SHORT TERM /SATURDAY NIGHT/...
Highs on Saturday will see a large range. North of the I-70
corridor, mid 30s are expected. South of the Ohio River, mid 50s
to near 60 are in the books, giving a 20 degree north-south
temperature gradient.

Behind the exiting low, any lingering rain in the east and south
will quickly end after nightfall and before midnight. Lows will
drop to 25-30 with northwest wind and building high pressure in
the Midwest.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Persistent zonal midlevel flow will evolve for the long term
period, providing a path for several embedded disturbances to
ripple to the E swiftly through the mid TN/OH Vlys, one after
the other. These quick-moving systems will allow the LL
baroclinic boundary to oscillate about the region N to S several
times, particularly during the heart of next workweek,
providing several chances for widespread, potentially wintry,
precipitation.

Quiet conditions will evolve for the start of the long term
period as sfc high pressure builds into the OH Vly Sunday
through Monday. Seasonably chilly conditions are on tap both
days as highs reach into the upper 30s and lower 40s, with lows
Sunday night generally in the upper teens to upper 20s N to S,
respectively.

Zonal flow persists as we progress into next week with an
active storm track continuing right through the ern third of the
CONUS, particularly through the OH/TN Vlys. The latitudinal
positioning of the boundaries will ultimately dictate what types
of pcpn and what impacts may be felt within the Mon night-Thu
time frame, but confidence is steadily increasing for the
potential for some light snow, particularly S of I-70 Monday
night into early Tuesday, as the first of two distinct systems
track through the region.

System 1 (Monday night into early Tuesday): amidst the zonal
flow aloft, an embedded disturbance will promote the development
of a weak sfc wave across the SE CONUS, with broad dynamically-
induced lift allowing for the expansion of a pcpn shield through
srn parts of the region and the TN Vly Monday night. At this
point in time, the track of this system, according to latest
ensemble mean trends, and the presence of a seasonably cold
airmass already in place, suggests light snow as a favored ptype
for most of the ILN FA, with a mix of rain/snow possible S of
the OH Rvr. The best overlap of lift/moisture/cold profile
should reside across the srn half of the ILN FA, suggesting the
steadiest/most widespread pcpn will, too, be focused across the
srn half of the local area (primarily near/S of I- 71). At this
juncture, it seems increasingly likely that accumulating snow on
the order of several inches will be possible, especially near
the OH Rvr. This being said, the band of steady snow could be
relatively narrow, with subtle shifts N or S still possible from
the scenario described here.

System 2 (late Wednesday into early Thursday): a slightly more
amplified setup than system #1, the midweek system should bring
with it a better chance for mixed wintry precipitation given
stronger dynamics and a tighter, less zonal LL baroclinic zone.
At this juncture, the highest probabilities for accumulating
snow with system 2 should be near/N of I-70, with better chances
for mixed wintry precipitation, or plain rain, across southern
parts of the area.

It is important to note that at these time ranges, the details
of what will unfold with both systems may not come into focus
for another day or two, but there are high probabilities for a
wet and/or wintry pattern to develop next week, with several
rounds of precipitation expected.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected tonight, with precipitation moving
in tomorrow morning, bringing a variety of aviation concerns.

In terms of precipitation type, a period of FZRA has been
included at KDAY/KILN, where freezing rain appears most likely
to occur. There is definitely a chance that a brief period of
FZRA could occur at the Cincinnati and Columbus TAF sites near
the onset time of precipitation, but confidence was not high
enough to include it in the forecast. This may need to be
adjusted in later updates.

Regardless of the above, warming temperatures will lead all
precipitation to turn to rain by late morning / early afternoon.
However, ceilings and visibilities will eventually lower to IFR
values, with some LIFR ceilings also appearing likely for some
of the TAF sites. Tomorrow evening, there may be a slow
improvement to aviation conditions, once a cold front moves
through the area and chances for precipitation come to an end.

Winds will generally be out of the east to southeast through the
majority of the forecast period, but there will be a notable
shift to the WNW over a period of a few hours in the afternoon
and early evening.

OUTLOOK...MVFR to IFR conditions are expected through Sunday.
MVFR to IFR conditions with snow are possible Tuesday into
Wednesday.

&&

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

&&

$$

SYNOPSIS...Franks
NEAR TERM...Hatzos
SHORT TERM...Franks
LONG TERM...KC
AVIATION...Hatzos