Area Forecast Discussion


158 
FXUS61 KILN 151638
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
1138 AM EST Fri Dec 15 2017
.SYNOPSIS...
A weak surface low will track through the Great Lakes today,
bringing a chance of light snow to northern Ohio. A surface 
ridge builds into the region tonight into Saturday. Persistent 
southwesterly flow will bring warmer temperatures into the area 
for the upcoming weekend, along with a chance of rain on 
Sunday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Not easy to draw in grids for cloud cover this morning, with
several bands/swaths of clouds at different levels, and a few
brief breaks to clear mixing in, especially in the southern half
of the forecast area. A bigger concern is whether or not lift
and steepening low level lapse rates associated with the Great
Lakes trough will be enough to develop any snow showers across
central Ohio today -- and the lack of moisture might point away
from any suggestions that accumulating snow will be likely to
occur. Flurries look like a near certainty, especially based on
current upstream observations. No changes are necessary to
current T/Td/Wind forecasts.
Previous discussion >
H5 s/w will swing across the Great Lakes today. A weak sfc low 
will develop and move through nrn Lake Huron. Trend of the 00Z 
models has been to move the pcpn farther north today, closer to 
the center of the low where the lift is better. Held onto some 
low chance PoPs in Central Ohio this afternoon, as the lift 
maximizes. Skies will remain mostly cloudy as low level moisture
will continue to pool ahead of cold front dropping into nrn 
Ohio.
Surface pressure gradient will increase this afternoon. Wind 
gusts of 20-25 kts will be possible during the afternoon. 
High temperatures will rise to around 30 in the north, and the
mid 30s across the south.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
As the H5 s/w pulls away tonight, a sfc ridge will build into
the ern Tennessee and Ohio Valleys. Clouds will linger tonight,
helping keep temperatures up. Lows will range from the mid to 
upper 20s.
Mid level ridge will begin to build in on Saturday. Southerly 
flow on Saturday will push temperatures a little above normal. 
Highs on Saturday to range from the lower 40s in the north to 
the upper 40s in the south.
The ridge will hold on Saturday night, bringing mostly clear
skies. For Sunday, the consensus of the models is to slow the
onset of pcpn. This should allow temperatures to warm enuf that
pcpn should fall as all liquid. Although the extended models 
agree on slowing down the onset, they disagree on coverage for 
Sunday. The NAM leaves the region dry, while the GFS brings in 
some scattered rain. The ECMWF and Canadian bring in a bigger 
swath of QPF. Ran a blend, which lowered PoPs down to high 
chance. Highs will range from 40 to 45 degrees.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
In split flow regime model solutions differ on phasing and 
timing of pcpn. Will follow a progressive soln with pcpn ending 
during the day Monday and then re-introduce a slight chc late 
Monday night into early Tuesday with mean trof developing across
the Great Lakes. Temperatures looks to continue a little above 
normal with Monday and Tuesdays highs ranging from the the 
lower/mid 40s north to around 50 south. 
In northwest flow regime surface high pressure to build into the 
region at mid week. This high will offer dry weather with the next 
chance of rain holding off until Thursday afternoon/Thursday night. 
Temperatures close to normal next Wednesday with highs from the 
upper 30s north to the mid 40s south. Reading warm above normal 
Thursday with highs of 45 to 50.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Generally VFR conditions are expected at the TAF sites through
the current forecast period. The only concern for MVFR ceilings
will be during a period of time this afternoon and possibly into
the early evening, but this should be limited to MVFR ceilings
in the 2kft-3kft range. There is a very slim chance of some
flurries at the DAY/CMH/LCK airports, but with no expected
impacts to conditions.
Gusty WSW winds will die down overnight, as any low clouds move
east of the area, with some mid-level clouds moving in through
early morning. Winds will increase from the WSW tomorrow, but
with generally clear skies expected.
OUTLOOK...MVFR ceilings and visibilities are possible from
Sunday night through Monday night.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...KC/Sites
NEAR TERM...Hatzos/Sites
SHORT TERM...Sites
LONG TERM...AR
AVIATION...Hatzos