FXUS61 KILN 030644
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
244 AM EDT Wed Sep 3 2025
.SYNOPSIS...
Moisture will begin to increase today in the southerly flow on the
back side of retreating high pressure. Most areas remain dry during
the daylight hours with a few showers and perhaps a thunderstorm
possible mainly this afternoon. A good chance of rain arrives
overnight into Thursday morning as a cold front pushes east through
the region. High pressure brings a brief return to dry weather Friday
before a secondary front offers another threat for showers and
thunderstorms Friday night into early Saturday. Cooler temperatures
closer to normal for early October will return for this weekend.
&&
.NEAR TERM /THROUGH TODAY/...
An amplified upper pattern remains in place with troughing across
most of the central and eastern CONUS. A deep mid and upper level
low over southern Canada will dig southeast into the Upper MS
Valley/Western Great Lakes today. An associated surface cold front
will advance into northwest Indiana by evening. Rain chances with
this feature remain west of ILN/S area with only an increase in
mid and upper level clouds this afternoon in the WAA pattern.
Meanwhile, a weak embedded shortwave moves thru the the mean trof
position across the Ohio and TN Valleys today and dampens out. There
could be a few showers and perhaps an embedded thunderstorm over
ILN/s east-southeast counties thru early to mid afternoon. Instability
is very marginal so do not anticipate a severe threat.
Cloud over is tricky with some increase in moisture associated with
this embedded shortwave and then being shunted off to the east early
to mid aftn. May see some early cloudiness especially across the
south and east followed by a decrease in clouds before high level
clouds stream in late in the day.
Temperatures in the mild southerly flow will top out generally in
the lower 80s this afternoon.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
An amplified upper pattern remains in place with troughing across
most of the central and eastern CONUS. The center of a deep mid and
upper level low pivots thru the northern Great Lakes back into
Ontario Canada overnight into Thursday. This will drive a surface
cold front into western Ohio by 12Z Thursday and east of the area
Thursday afternoon. Moisture and forcing increase with the approach
of the front tonight with showers and thunderstorms overspread the
area after midnight. Instability is marginal and elevated - so severe
weather is not anticipated. The front is progressive with rain
chances ending late Thursday morning in the northwest and last in the
southeast during the mid to late afternoon hours. Rainfall for the
event is expected to be between a quarter and a half inch for most
locations.
On the warm side of the front lows tonight range from the upper 50s
to lower 60s. Highs on Thursday range from the upper 60s northwest
to the lower 70s southeast.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
On Thursday evening, a deep stacked low will be centered over
northern Ontario, with broad troughing in place across much of the
eastern CONUS. This low will remain in place, barely moving at all,
through much of the weekend. An initial cold front will be moving
out of the ILN CWA by late Thursday afternoon, which will allow for
the extended forecast period to start out dry. With another wave
upstream, and a tightening pressure gradient (with a surface trough
over Michigan) the boundary layer flow will shift to the south and
then southwest on Friday. One impact for Friday will be a notable
increase in temperatures from Thursday, though with a sharp
gradient. Highs will be in the mid 70s in the northwest ILN CWA, and
mid to upper 80s in the southeast ILN CWA. Another impact will be an
increase in winds as the pressure gradient increases. Gusts in the
20-30 MPH range are in the forecast for now, though there is some
potential for slightly stronger gusts if boundary layer mixing is a
little deeper than currently expected.
The next chance of precipitation is expected Friday night into
Saturday. Although a surface cold front will be clearing through the
area by Friday evening, theta-e advection aloft -- ahead of a
shortwave -- will be the main driver for precipitation during this
time frame. Once this wave clears the area, with a significant drop
in 850mb theta-e by Saturday afternoon, precipitation chances will
come to an end. Some elevated instability could allow for isolated
thunder, but with a stable boundary layer Friday night into Saturday
morning, no hazardous weather is expected.
Starting Saturday, temperatures will once again be quite a bit below
normal, with highs in the upper 60s to lower 70s. Surface high
pressure will then gradually shift east through the region on Sunday
and Monday, with a slight warming trend expected going into early
next week. Precipitation chances next week are quite uncertain at
this point, though eventually some moisture may drift northward into
the area on the back side of the surface high.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
Cloud over is tricky with some increase in moisture associated with
a weak embedded shortwave early today. There are some indications
that stratus and fog could develop and affect the southern TAF sites
early this morning. At this time have allowed IFR conditions to
develop at KLUK but kept KCVG and KILN VFR. Will continue to monitor
satellite and observational trends.
This moisture is shunted off to the east early to mid aftn with
early cumulus clouds especially across the south and east
decreasing. WAA mid and high level clouds stream in late in the day
into this evening ahead of an approaching cold front. Shower and
embedded thunderstorm chance ramp up after 06Z with the cold front
moving into western Ohio by 12Z Thursday. Have pcpn chances at the 30
hour KCVG TAF sites after 07Z with MVFR cigs developing.
OUTLOOK...MVFR ceilings and visibilities are possible late Wednesday
night into Thursday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...Hatzos
AVIATION...AR
