Port Jefferson, Ohio Weather Forecast Discussion

491
FXUS61 KILN 050132
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
932 PM EDT Thu Sep 4 2025
.SYNOPSIS...
Showers and thunderstorms will be possible Friday evening into
Saturday morning as another cold front moves through the region. High
pressure moves over the region early next week, providing below
normal temperatures and dry conditions.
&&
.NEAR TERM /THROUGH FRIDAY/...
Evening update...
The cold front has now shifted to the far southeast portions of the
local area, stalling over Scioto County OH and Lewis County KY. Given
the lingering moisture along the front, some mentions of valley fog
were added for portions of southern Ohio and northern/northeast
Kentucky. Otherwise, temperatures are beginning to cool under mostly
clear skies and decreasing winds. No additional forecast changes were
made.
Previous discussion (200 pm)...
The cold front has now moved through Cincinnati, Wilmington, and
Columbus, decreasing shower potential in these areas for the rest of
the day. As the front moves southeast, additional showers and
downpours have formed, but no lightning has been detected. This will
likely change over the next couple of hours with additional heating
across southern Ohio and northern Kentucky. Drier air moves in
throughout the rest of the afternoon and evening, drying out the area
into the overnight.
Weak high pressure becomes more nebulous overnight as a deepening
low pressure moves into the upper Midwest. Most locations likely see
light and variable flow overnight, but wind exposed locations will
see a light southerly flow heading into Friday morning. Low
temperatures are 5 to 10 degrees below normal so expect chilly
conditions during the morning.
&&
.SHORT TERM /FRIDAY NIGHT/...
A large upper level trough will be positioned over southern and
southeast Canada Friday morning. A strong shortwave trough will dive
southeastward into the base of the trough, resulting in a deepening
low pressure over the Great Lakes. In response to the depending low
pressure, southwesterly flow increases quickly over the local area,
with gusts of 20-25 mph expected. Even with some overspreading mid
and upper level clouds, temperatures warm rapidly into the afternoon
with many locations warming into the 80s. East-central Indiana and
west-central Ohio may be the only locations to stay in the 70s as the
front moves into those locations earlier in the afternoon.
Severe threat: As temperatures warm and low level moisture increases
into the afternoon, the forcing for thunderstorm initiation is still
off to the west, but will intensify into the evening hours and the
front drops southeastward across the area. This means that
thunderstorm development likely won`t occur until 5- 7pm, continuing
beyond that through the evening hours. The best environment is
expected ahead of the front, with scattered thunderstorms developing
from the tri-state into south- central and southern Ohio. The
shortwave is elongated and stretched out so repetitive development is
possible over the same areas before the activity shifts southward
with time. Bulk-shear upwards of 40 knots will support severe storm
potential with hail and damaging winds the primary threats. The
Marginal Risk from SPC was upgraded to a Slight Risk (Level 2 of 5)
across southern Ohio and northern /northeast Kentucky. This area is
favored due to the intersection of stronger shear and higher
instability.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
The first half of Saturday has become a bit more challenging as the
evolution of the trough continues to trend a bit more amplified. This
amplification enables stronger forcing over the Ohio Valley,
resulting in lingering rainfall chances into the early afternoon,
primarily south and east of the I-71 corridor. Confidence remains
high that dry air will eventually blast in from the west, providing
drier conditions and partly cloudy skies the rest of the day.
A few showers are possible again Saturday night across the west-
central Ohio as a potent shortwave moves through the base of the
longwave trough. The longwave trough axis shifts eastward across the
area on Sunday with surface high pressure building across the Ohio
Valley throughout the day and into the evening hours. Northwest winds
will be noticeable Sunday morning and afternoon before the high
pressure moves overhead Sunday night.
Monday through Wednesday feature below normal temperatures,
especially during the morning hours. Sunday night into Monday morning
will likely be the coldest, with low to mid 40s area wide. A
gradually warm up with afternoon highs occurs into midweek as winds
turn out of the southwest. Wednesday afternoon may get back to normal
temperatures with the southwesterly flow.
There are some hints that another front will approach the region on
Thursday, but initial indications are that it will be fairly weak,
and likely dry.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Clouds have decreased across the area, and this is expected to
remain the case through the overnight. Light westerly/northwesterly
winds decrease after 00Z, becoming light and variable or prevailing
out of the south.
Southerly winds increase throughout the morning and afternoon,
becoming more southwesterly/westerly by the end of the period. Wind
gusts are between 20 and 25 knots ahead of the approaching cold
front. The cold front will begin to move through DAY/CVG/LUK around
22-00Z, causing winds to shift out of the northwest.
Eventually will see some VFR cumulus form throughout the afternoon
with scattered showers ahead of the front between the 18Z-00Z time
period. Confidence is fairly high that any thunderstorm activity will
develop and occur southeast of the TAF sites, but CVG/LUK/ILN are on
the edge of of where the development is possible. Have limited PROB30
groups to showers only for now, due to the lower confidence in
thunder. All other remaining sites may see showers mentions during
the 06Z and 12Z TAF updates.
MVFR CIGs are possible, but would likely develop after 06Z and closer
to 12Z. No mention in the TAFs at this time.
OUTLOOK...MVFR visibilities are possible Friday night with another
round of showers and embedded thunderstorms.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...McGinnis
NEAR TERM...McGinnis
SHORT TERM...McGinnis
LONG TERM...McGinnis
AVIATION...McGinnis

NWS ILN Office Area Forecast Discussion