Area Forecast Discussion
Issued by NWS Wilmington, OH
FXUS61 KILN 110545
Area Forecast Discussion
National Weather Service Wilmington OH
1245 AM EST Sun Dec 11 2016
A low pressure system will eject northeast from the Plains into
the Great Lakes Sunday into Monday. Snow will develop ahead of
this system tonight and then a mix of rain and snow is expected
Sunday before precipitation ends early Monday. High pressure
returns late Monday.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Not many changes to current forecast as widespread WAA/ isentropic
upglide has allowed a band of snow to move into our northern zones
with a couple of sites already reporting. The main question is
that dry air remains in the low levels and will take a little bit
of time to saturate as the band heads north. Latest HRRR run then
has snow filling back in across the northern zones early Sunday
morning. Latest run of the NAM also hints at this while
advertising a sharp cut off. Have kept forecast advertising
accumulating snow along and north of Interstate 70. New zones out.
Still have a few flurries flying across the CWA this afternoon,
particularly across west central Ohio and east-central Indiana. No
accumulation is expected from the flurries through sunset.
Focus then shifts to the next system which will begin to affect
portions of the CWA tonight. Low pressure will eject out of the
Rockies and into the central Plains tonight. And as high pressure
over the Ohio Valley moves into the Mid-Atlantic, a return flow
will set up, allowing the low levels to moisten up and warm
advection will also start to kick in and produce more clouds.
Isentropic lift will also promote the development of snow,
although much of our guidance suggest a fairly sharp southern cut
off where accumulating snow will occur. At this point in time,
the highest confidence in accumulating snow looks to be just north
of the Interstate 70 corridor, favoring a GFE/SREFS blend.
Highest snowfall accumulations are forecast to reside across our
northern most counties, namely Auglaize, Mercer and Hardin and a
Winter Weather Advisory has been issued. Further south of this
area toward the Interstate 70 corridor, snowfall accumulations are
expected to remain below Advisory criteria but enough to
potentially result in slick travel late tonight/early Sunday.
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
Snow continues Sunday morning mainly across the far northern
portion of the CWA, but precipitation will overspread the entire
area during the afternoon/evening as a favorable jet develops
over the CWA ahead of low pressure which will move into the upper
Midwest by days end. In addition to supporting precipitation, the
southwesterly jet will also result in the rain/snow line shifting
north through the day where much of the CWA is likely to
experience rain by late afternoon, except for perhaps the extreme
northern counties within the Advisory area.
Surface temperatures will likely continue to rise into the
overnight hours, with rain being the primary p-type across the
CWA. Then, as low pressure moves through the Great Lakes late Sunday
night, this will allow a cold front to move through from the west,
ending the precipitation chances Monday morning. The remainder of
Monday dries out and clouds may even break for some sunshine later
in the day.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
With the departing frontal system leaving the area becoming under
the influence of a shallow ridge over the southern CONUS...but low
level moisture will linger for Monday night. So despite Cold air
advection over especially the northern half of the forecast
area,there will only be occasional breaks in cloud cover. There will
be a pretty tight gradient of temperatures on especially Tuesday
into Tuesday night with the passage of the upper low over central
and then SE Ontario, with the weak ridging in the south. The only
potential for precipitation will come in the form of light snow
showers in NW flow with the passage of the upper low, but limited
More significant Cold advection and dry conditions will continue the
below normal temperatures through the work week, with single digit
overnight lows Wednesday night and Thursday night. For Friday into
Saturday, moisture returns to the region with the passage of
another shortwave, with precipitation onset beginning as snow and
then changing over to rain during the day on Saturday.
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Moisture is increasing ahead of low pressure. Snow is developing
near northern sites and will probably reduce flight conditions
there to MVFR early in the forecast. Rain will then overspread all
sites later in the forecast. MVFR is expected at all sites with
the rain. CVG may see IFR ceilings late in its 30 hour TAF in
lingering low level moisture behind the rain. Winds will start out
of the southeast under 10 knots, increasing to around 12 knots out
of the south by mid day. A shift to west is forecast at CVG late
in the forecast.
OUTLOOK...MVFR/IFR ceilings and visibilities possible Monday
OH...Winter Weather Advisory until 6 PM EST this evening for OHZ026-