049
FXUS61 KILN 261758
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
158 PM EDT Thu Sep 26 2024

.SYNOPSIS...
As the remnants of Helene track north, rain will spread into the
area. In addition, it will become breezy on Friday. Low pressure
will then linger in the Ohio Valley through the weekend keeping
conditions unsettled.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Morning update...
No major changes to the near term forecast with widespread cloud
cover enveloping the region. Rain moving into the area remains
very light.

Adjustments for winds and potential wind headlines for remnants
of Helene will be made in the coming hours as the full 12Z
model guidance becomes available.

Previous discussion...
Upper low over the lower Ohio Valley will drop south into the
mid South today. A disturbance rotating around the low will move
westward across the southern part of the forecast area this
afternoon. Remnant surface trough will become reoriented more
east-west across southern Ohio into Kentucky. This will result
in showers developing and moving west over mainly the southern
counties late this morning through this afternoon. Highs will be
in the 70s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Wind Advisory update...
In collaboration with surrounding offices, a wind advisory has
been issued from 10 am to midnight, for winds of 25 to 35 mph
and gusts between 45 and 55 mph. The 12Z suite of guidance
increased in wind values, as the remnants of Helene are expected
to approach the Ohio Valley Friday morning. The pressure
gradient will drive strong northeasterly to easterly winds
beginning in the morning, intensifying into the early and late
afternoon. As Helene continues to gradually strengthen in the
eastern Gulf, there is still some uncertainty as to the overall
low pressure value as it enters the Ohio Valley. There is
certainly the potential for lower and higher wind values
depending on the magnitude of the low pressure and the exact
track. However, enough confidence was in place to start with a
wind advisory focused over a large portion of southwest Ohio,
southeast Indiana, and northern Kentucky. The advisory could be
expanded or potentially upgraded to a High Wind Warning if
necessary.

Previous discussion...
The remnants of Helene will lift north and then curl northwest,
passing south of the forecast area, as it gets absorbed into the
preexisting upper low which will be shifting into the Tennessee
Valley.

Showers will be increasing in coverage, especially the latter
part of the night. The showers will pivot in a broad band on
Friday afternoon. Rainfall amounts will be 1 to 2 inches across
southern counties with less amounts further north,

In addition, winds will be increasing as the pressure gradient
tightens with the approach of the remnants. There will be a very
strong low level jet, but with a very moist environment, expect
mixing to not be very deep. However, it will not have to in
order to get some rather gusty winds. At this point, have kept
winds below advisory criteria, but there is certainly room for
those gusts to be higher.

There will be rather narrow diurnal range with lows in the 60s
and highs in the 70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
For Friday night, the remains of Helene continue to push west of the
area as it gets wrapped up into the mid level low in the lower Ohio
Valley. Helene`s continued weakening and westward progression will
bring a sharp rainfall cutoff from east to west across the mid Ohio
Valley, but some uncertainty in how quickly the lingering bands will
remain. Greatest confidence in higher precip chances is near the
Ohio/Indiana border and KY regions due south of Cincinnati. Winds
will also decrease Friday night as Helene continues to weaken and
push west.

Once remains of Helene get wrapped into the mid level closed low, it
remains just to the southwest of the forecast area through Saturday
morning before slowly becoming more broad and on a slow weakening
trend as it slowly pushes east and becomes centered roughly just
south of the Ohio River through the remainder of the weekend. Some
spread in the solutions for timing of the eastward progression of
the mid level low, but overall will bring periods of rain through
the weekend with a chance for thunderstorms on Sunday as the closed
low begins to open up with an approaching cold front to push toward
the region later on Sunday and into Monday. The front begins to push
through the region late Monday into Tuesday, bringing a more focused
chance for showers and storms. A return to mid level ridging and
high pressure with rising temperatures for Wednesday.

With plenty of cloud cover and moisture in the region, temperatures
will be in the mid 70s into early next week, with lows in the upper
50s to lower 60s.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Still dealing with lingering MVFR CIGs at some of the sites
early this afternoon. Improvement to VFR is expected through the
afternoon before MVFR CIGs settle in for the remainder of the
TAF after 00Z.

The TAF period now includes the onset of stronger winds & wind
gusts Friday afternoon. These values will likely need some
adjustment with future forecasts. LLWS has also been added in
for CVG/LUK. ILN may be needed with higher confidence.

Plentiful tropical moisture will provide low-end MVFR CIGs, with
MVFR VIS expected in moderate rain. IFR restrictions can`t be
ruled out.

OUTLOOK....MVFR ceilings likely Friday night and possible again
Saturday through Monday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Wind Advisory from 10 AM Friday to midnight EDT Friday night
     for OHZ042-051>054-060>063-070>072-077>081.
KY...Wind Advisory from 10 AM Friday to midnight EDT Friday night
     for KYZ089>100.
IN...Wind Advisory from 10 AM Friday to midnight EDT Friday night
     for INZ050-058-059-066-073>075-080.

&&

$$
SYNOPSIS...
NEAR TERM...McGinnis
SHORT TERM...McGinnis
LONG TERM...JDR
AVIATION...McGinnis