969
FXUS61 KILN 212316
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
616 PM EST Thu Nov 21 2024

.SYNOPSIS...
Cool temperatures and chances for precipitation remain in place
through the end of the working week. Dry conditions and near normal
temperatures return to the region for Saturday and Sunday. Precipitation
chances increase again on Monday with the next disturbance.

&&

.NEAR TERM /THROUGH FRIDAY/...
A second vort lobe rotating around the parent low will be
pivoting through the region at the start of the near term. This
will provide the forcing needed for widespread snowfall.
Guidance suggests that the more negative values of omega
(ascent) will pivot primarily through central Indiana and past the
Tri-State before midnight. This echoes what was seen on the
mid-night shift with regards to a westward shift in highest PoP
potential. Have continued to trend higher PoPs over the Tri-
State and OH/IN border this evening into overnight.

Pavement temperatures still look to remain above freezing and
recent pavement models suggest that it will be well past
midnight before pavements fall into the 30s. With that being
said, as we saw this afternoon, any area experiencing efficient
snow rates may have some accumulation on overpasses, sidewalks/
parking lots/ elevated surfaces and grassy areas. Thinking
continues to be that an additional 1-2 inches will fall around
the Tri-State with snow tapering off after 2AM. Due to these
factors, the timing falling during a weekday rush hour commute,
and this being the first somewhat impactful snow of the
season... have continued the Winter Weather Advisory for those
southwest counties.

While daytime highs have trended a bit cooler than most guidance
suggested, the coldest 850 temps and strongest CAA have now
departed the region. Even so, have trended nighttime lows
slightly below guidance and dropped the area into the upper 20s.

&&

.SHORT TERM /FRIDAY NIGHT/...
Upper level system continues to slowly move off to the
east, though continues to be the dominant influencer for our
sensible weather for at least another day. Cyclonic flow moving
through the region supports persistent low cloud cover and
additional moisture being pulled off of the Great Lakes.

Overall, expecting this to be a dreary day. Low ceilings,
northwesterly winds around 15 MPH with gusts to 25, and on and
off rain showers/ drizzle. There will be a slight warm up as
weak warm air advection is wrapped around the low and Friday
high temperatures reach the 40s. However, since the day will
still be rather breezy, feels-like temps will be in the 30s.

By Friday night, the parent low finally moves off toward the
Atlantic Coast and is slowly replaced by ridging in the Midwest.
The area will begin to dry out and precipitation chances
decrease from west to east. Wind gusts subside slightly and
overnight low temperatures into Saturday fall to the upper 30s/
low 40s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Broad, low-amplitude mid-level ridging will build into the area over
the weekend. This will translate east as a short wave moves out of
the northern Plains and tracks across the Great Lakes early next
week. So surface high will pass south of the area allowing for a
warming trend with temperatures getting back to or slightly above
normal by Sunday. Then showers will develop and pass across the
region ahead of a cold front on Monday into Monday night. Still some
spread in guidance, so exact window when the front passes is a bit
uncertain.

Mid-level flow will become more zonal mid week. A short wave will
move out of the central Rockies and push eastwards into the Ohio
Valley by Thursday. There is a fair amount of spread on how that
evolves, and even if it comes out in multiple pieces. This pattern
favors low pressure passing across Tennessee and Kentucky with a
shield of precipitation north of that spreading across the forecast
area. Timing is uncertain, but greatest chance of rain at this point
is Wednesday night into Thanksgiving. Highs will be below normal
during this period with lows near normal.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
Snow will be the main impact through about 05Z, with IFR
conditions at KCVG/KLUK/KDAY/KILN, and generally MVFR conditions
at KCMH.

Once the snow comes to an end, visibilities will improve, but
ceilings will likely remain IFR to MVFR. There will also be a
notable wind shift overnight, as winds shift from SW to NNW over
the course of a few hours between 01Z and 06Z, and then back
slightly to the WNW by 12Z. Through the overnight hours, winds
will generally be around 10 knots, but they will begin to
increase again tomorrow. Some gusts of around 25 knots are
expected tomorrow afternoon.

There may be a brief period where ceilings break to VFR tomorrow
morning, before MVFR ceilings fill back in for the rest of the
day. Although not in the TAF, some IFR ceilings are possible
tomorrow afternoon as well. Finally, there will be a chance of
rain tomorrow, indicated in the TAFs with a -SHRA or VCSH. This
rain could reduce visibilities, but aforementioned ceilings will
be the more significant issue for aviation.

OUTLOOK... MVFR ceilings will continue through Saturday. MVFR
conditions are possible again Monday night into Tuesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Winter Weather Advisory until 4 AM EST Friday for OHZ042-
     060>062-070>072-077>081.
KY...Winter Weather Advisory until 4 AM EST Friday for KYZ089>100.
IN...Winter Weather Advisory until 4 AM EST Friday for INZ050-058-
     059-066-073>075-080.

&&

$$

SYNOPSIS...CA
NEAR TERM...CA
SHORT TERM...CA
LONG TERM...
AVIATION...Hatzos