Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
707 am EST Monday Feb 8 2016
a cold front will cross the area today combined with a
deepening trough aloft. Occasional snow will continue into midweek
as the trough aloft moves slowly east across the area. It will get
cold enough by Tuesday night for lake effect snow. High pressure
will build across the Ohio Valley on Thursday. An Arctic front will
drop across the area Friday night.
Near term /until 6 PM this evening/...
refined the snow accumulation forecast a bit for the early morning
update. Unlikely that most areas will see much snow accumulation
today...generally "less than an inch" or "little/none".
Temperatures will be too marginal unless it were to snow hard for
a while. Updated the hourly temperature and dew point forecast
based on the current trends. No other changes.
Original "today" discussion...
coverage of precipitation is still limited but should expand this morning
as the short wave over the lower Ohio Valley slides east.
The boundary layer remains rather warm and dew points are coming
up to around freezing. Cold advection is underway aloft and to the
west though and I think as soon as the wind can shift more to a
southwest to west direction then the boundary layer can chill
enough to get some wet snow. Also...with enough dynamic cooling
aloft...the column aloft could cool when the upward motion becomes
strong and perhaps some wet snow can mix down to the surface.
Temperatures are marginal and there could well be some variation
by elevation as well. Given all of the above factors... the
forecast will remain rather vague today with rain and snow in the
forecast. It will take until later in the day to get any snow to
the Ohio PA border where temperatures will be rather mild today.
Cannot rule out a slushy coating of snow if the snow were to
come down hard enough but it will not be cold enough to stick on the
Short term /6 PM this evening through Wednesday night/...
the main trough aloft will drop southeast tonight...probably diving
to the Ohio Valley and south. This puts the forecast area on the
fringe of a broad area of light to moderate snow tonight. We
could see a couple of inches of snow brush the southern counties
south of Route 30 with less organized snow and snow showers
elsewhere with anywhere from a coating of snow to locally an inch
or two. Most areas will probably at least get the ground whitened.
Additional snow showers will continue on Tuesday into Tuesday
night under the trough aloft with generally light amounts.
The boundary flow will likely stay west southwest tonight and it
will not get cold enough aloft for lake effect snow tonight into
Tuesday. It will probably be cold enough for lake effect starting
Tuesday night and certainly by Wednesday. The flow will start out
west southwest and gradually veer more northwest during the day
Wednesday. Snow amounts will probably require at least an advisory
and perhaps a warning but too early to make a specific forecast.
Will mention accumulating snow in the hazardous weather outlook
Long term /Thursday through Sunday/...
cold northwesterly winds will continue to flow across Lake Erie
Thursday with a gradual decrease in the coverage. A clipper storm
system will move across the Central Lakes on Friday. This will
provide a reinforcing surge of cold air for Friday night into the
weekend. So after a brief lull in the lake effect snow Thursday nigh
into Friday it looks like the lake effect snow will reestablish
itself. This may end up being some of the coldest air of the winter
season with Lake Erie nearly ice free. Difficult to pinpoint
snowfall amounts in the long term but the primary snowbelt could get
Aviation /12z Monday through Friday/...
occluded front over central areas of Northern Ohio as of 1130z.
Any light rain was located near and just to the east of it. As the
light rain continues to move east with the frontal boundary
ceilings will lower to low end MVFR. Cant completely rule out a
brief snow shower through early afternoon but believe most of the
precipitation will remain liquid. However if any snow can fall and
help chill the lower levels a bit more there could be some patchy
Colder air arrives this evening into the overnight with the
precipitation all snow from that point on. There could be some
light accumulations anywhere but the slightly higher amounts may
end up being across the southern taf sites with an inch or so
Southerly winds across the east this morning will shift to the
southwest. Westerly winds will slide eastward across the region
tonight. Wind speeds will generally be under 10 knots.
Outlook...non VFR possible through the week in snow and lower
ceilings as a series of clippers move across the area.
winds are expected to be variable int direction today as low
pressure wobbles across southern Ontario and Lake Erie. As the low
deepens slightly and gradually moves eastward on Tuesday it will
allow a westerly wind to increase to 20 to 25 knots. Winds become
more northwesterly on Wednesday and persist into Thursday...
remaining in the 20 to 25 knot range.