Area Forecast Discussion
Issued by NWS Wilmington, OH
FXUS61 KILN 092112
Area Forecast Discussion
National Weather Service Wilmington OH
412 PM EST Fri Dec 9 2016
Building high pressure will keep temperatures below normal tonight
into Saturday. Then a complex low pressure system will affect the
Ohio Valley Saturday night into Monday, bringing a mix of snow and
.NEAR TERM /THROUGH TONIGHT/...
Cold air stratocu and isolated flurries continue to affect the
region as the low level moisture remains trapped over the region.
Satellite loop is showing isolated clear spots but these should
come and go over the next few hours.
West-northwest flow at H5 will help a broad weak surface high
to build east overnight. The big question is whether the low
clouds will break up overnight. The models are showing differing
solution in how they handle the H9 moisture. Leaned towards the
more pessimistic solution and kept them lingering for most of the
night. Even if they do break up, mid clouds working eastward will
keeps skies mostly cloudy.
Another cold night is expected with lows in the mid to upper
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Surface high pressure will cross the region on Saturday. This
high will provide dry weather and continued cold temperatures.
With a mix of clouds and sun, highs will range from the upper 20s
across the north to the lower 30s across the south.
As the H5 flow backs Saturday night, isentropic lift increases.
The 12Z remains the outlier keeping the waa pcpn north of the fa.
The other models are farther south, bringing the axis of the pcpn
across nrn IN into nrn OH, with the nrn part of the fa on the
southern edge of the steady snow. The 18Z has come in farther
south, matching closer to the other 12Z solutions.
Kept snow chances from about I-70 north with perhaps an inch or
two of snow across the far north overnight. Lows Saturday night
will be in the lower to mid 20s.
WAA pcpn continues to slide east across ILN/s nrn counties Sunday
morning with pcpn filling in from the west durg the afternoon as
favorable lift develops associated with 8H 55-60 kt low level jet.
Expect pcpn to remain snow across the far north with a snow to
rain/snow mix acrs the central and south. Eventually under the
influence of waa, the entire cwa turns over to rain Sunday night.
An additional additional inch of snow accumulation is possible
prior to the change to rain across the far north. Temperatures on
Sunday will warm to the mid 30s far north to the lower 40s far
.LONG TERM /MONDAY THROUGH THURSDAY/...
Monday starts with a strong surface low and warm front through the
Ohio Valley, followed sharply by a cold front and rapidly falling
temperatures from west to east. This follows a H5 shortwave moving
east past the Great Lakes region. High pressure at the surface will
be ushered in behind it and last until about Wednesday. On
Wednesday, the zonal H5 flow will contain a broad trough pushing in
from the west and a broad area of frontogenetic forcing will occur
in the mid levels over the eastern U.S. European model is quicker to
push the deeper moisture east on Wednesday and subsequently much
lighter in any potential for snow.
Temperatures should remain cool and thicknesses support snow for the
remainder of the forecast.
High pressure builds at the surface Wednesday night and dries out
the region through Friday.
Models continue to advertise a cool extended period with below
normal readings regardless of the timing or placement differences of
the Wednesday system.
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
MVFR ceilings at most TAF sites to start the period should lift to
VFR later this afternoon. VFR ceilings will likely persist through
much of the night. There is some potential for ceilings to lower
back to MVFR especially near KDAY/KILN. Expect lower clouds to
decrease towards 12Z. But a mid deck will remain through the end
of the TAF period. West winds 10 to 15 kt will diminish towards
00Z and then back slightly.
OUTLOOK...MVFR/IFR ceilings and visibilities possible Sunday
afternoon into Monday morning.