Information is from the NWS Wilmington, OH Office

ILN Area Forecast Discussion/SKEW-T

FXUS61 KILN 231049

Area Forecast Discussion
National Weather Service Wilmington OH
649 AM EDT Sun Sep 23 2018

Moisture will overspread a stalled front in the Tennessee
Valley today, bringing rain across southern portions of the
region. Additional moisture will return to the region early
next week. This will result in several rounds of showers and
thunderstorms with heavy rain possible through the middle of the
week. A strong cold front will move through the area Tuesday
night into Wednesday.


A disturbance embedded in broad southwest flow is forecast to
lift across the southern third of the forecast area this
morning. This will combine with a low level jet to produce a
favorable region of lift. Models bring an area of showers across
nrn KY into south central Ohio this morning. With precip water
approaching two inches, a period of moderate to heavy rain is
possible. It is looking like there will be a sharp cut off to
the pcpn on the nrn side, so quickly dropped PoPs down to near
zero for the nrn half of the fa. Will hold off on issuing any
flood watch as the latest meso-scale models are suggesting that
the heaviest pcpn could stay just to the south of the fa.

By afternoon, the better pva will be moving east of the region,
pulling the better pcpn chances with it. Warmest highs today
will be found in the north were lower 70s are expected. In nrn
KY and south central OH, highs will be held down in the mid to
upper 60s.


Tonight the H5 flow backs a little more to the southwest and
pcpn spreads quickly back to the north. Lows tonight will be in
the upper 50s to lower 60s.

By Monday, an H5 s/w will be rotating out of the MS valley into
the region. Rain is expected to increase in coverage in the lift
out ahead of the s/w. There should be enough instability for
some scattered thunder. Highs will only make it into the lower
70s on Monday.

Showers and isolated thunderstorms will continue across the
region Monday night into Tuesday as the region remains in
broad southwest flow aloft. At the sfc, precipitable water
values will remain near 2 inches. Models are suggesting the
possibility of some heavy rains, but with differences in timing
and placement will hold off on any flood watches. Highs Tuesday
will be a little warmer, in the mid 70s.


A cold front is forecast to approach Tuesday night with showers
and thunderstorms. Models suggest high moisture content, with
precipitable water values possibly near 2 inches, along with
some shear. However, CAPE is forecast to be on the low side. So
confidence in widespread severe is low, but given presence of
shear and stronger forcing, strong to damaging wind gusts may be
possible especially if higher instability can be realized. This
threat is reflected in the SPC Outlook. And given high
moisture, heavy rainfall may promote localized flooding.

Confidence on the exact frontal passage is still somewhat uncertain,
but latest trends favor the front moving east through the CWA
Wednesday morning. PoPs lower behind the front as drier air begins
to filter in. A shortwave and reinforcing front follow Thursday
night into early Friday, but with much less moisture to work with it
looks like only a slight chance of showers as these features move
through. While seven days out, right now Saturday appears dry with
high pressure building in.


Large area of rain just south of KCVG/KLUK will not make any
headway further north this morning. The northern edge appears to
be well-defined and the east-northeast movement of the area
runs parallel to this edge, limiting the potential of activity
reaching the southern TAF sites today. Lower cigs will remain a
possibility this morning but until upstream observations drop to
the MVFR range, forecast was kept VFR until at least late

The overnight period will finally see a more northward
progression of the rain shield into the tri-state area and
CVG/LUK TAFs. It may nose into the remaining TAFS at the tail
end of the period, but there remains high variability in the
models and low confidence in how the system is going to evolve,
even in the near-term forecast.

DAY/CMH/LCK and to a lesser extent ILN have been kept VFR with
cigs dropping into the MVFR range after sunset.

OUTLOOK...MVFR ceilings and visibilities likely on Monday.
Thunderstorms possible Monday through Wednesday.






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