Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
1004 am EST Sat Feb 6 2016
dry conditions and slightly above normal temperatures will
persist today into Sunday as high pressure slides slowly off to
the east. A strong cold front will usher in a much colder airmass
for the upcoming work week. In the wake of the cold front...scattered
snow showers will be possible through middle week.
Near term /until 6 PM this evening/...
high pressure is situated southeast of the forecast area. SW flow will develop today
and bring warmer temperatures into the area. High temperatures in
the upper 30s to middle 40s are expected. Dry conditions are
expected. An area of clouds over central Indiana will move into
the forecast area this afternoon however expect some decrease in this cloud
cover as it does move east. Have partly cloudy skies in the
forecast for this afternoon.
Short term /6 PM this evening through Monday night/...
some short wave middle/upper level ridging will briefly build into
the area tonight into Sunday morning ahead of short wave energy
dropping down across the western Great Lakes. This energy will
help carve out a deepening upper level trough across the eastern
United States through the first part of the upcoming week. An
associated cold front will usher in some much colder air into the
region Monday into Monday night.
Models continue to differ on the strength of the low level
convergence and how fast moisture will be pulled up into our area
ahead of the approaching cold front Sunday night. The 00z GFS and
CMC are more aggressive...developing precipitation across western portions
of our forecast area Sunday evening...while the 00z European model (ecmwf) and NAM are
slower...bringing the best moisture/forcing into eastern portions
of our forecast area in the 06z-12z time frame. Will go ahead and allow for
chance probability of precipitation to develop west to east Sunday evening and then have
likely probability of precipitation across the east later Sunday night into early Monday
morning. Cold air advection will develop west to east behind the front late
Sunday night into Monday. It looks like low level thermal fields
should remain warm enough to keep most of the precipitation Sunday night
all rain...so will just allow for a mix to develop through the pre
dawn hours...and this should help limit any snow accumulations for
Monday becomes more interesting as good cold air advection will develop across
the area. Temperatures will start out in the middle to upper 30s and
should remain fairly steady or begin to drop off some through the
afternoon. Forecast soundings are indicating increasing low level
lapse rates as we progress through the day and the snow squall
parameter is forecast to increase through the afternoon...especially
across western portions of our forecast area. Thus...expect to see scattered
snow showers across the west and rain/snow showers across the east
become a bit more widespread through late morning and into the
afternoon. In continued cold air advection...precipitation should transition over to all
snow showers in the east through the afternoon hours.
Accumulations will be at least somewhat dependent on how fast the
cold air moves in and its affect on boundary layer temperatures.
For now will limit accumulations on Monday to less than an inch
and primarily across western portions of our forecast area. Scattered snow
showers and some additional light accumulations will then be
possible across the entire area into Monday night as we remain in
cyclonic low level flow and also get into a fetch off of Lake
Long term /Tuesday through Friday/...
colder air arrives more in earnest by Tuesday with disturbances
bringing flurries and snow showers. Again nothing significant but
minor accumulation should be the rule. Series of disturbances
finally get pushed off to the east by late Wednesday and Wednesday
night. Should dry out for Thursday. Some indication of a
disturbance with limited moisture late Thursday into Thursday
night but will keep benign weather in for now with cold
temperatures. Temperatures generally near guidance.
Aviation /14z Saturday through Wednesday/...
some restrictions in visibilities this morning as light winds and some
patchy cirrus has allowed dewpoint depressions to approach zero in
places. Any patchy ground fog will quickly burn off this morning
as the sun comes up. Weak surface ridging will remain off to the
southeast this afternoon with relatively light winds forecasted
thanks to a weak pressure gradient.
Sunday morning the terminals will fall in between two upper level
disturbances with clouds approaching from the northwest. During
the day Sunday winds will start to pick up speed as the pressure
gradient tightens. Forecast soundings from the GFS and NAM are
showing some wind gusts possible Sunday afternoon.
Outlook...MVFR ceilings and visibilities possible from Sunday night into