Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
751 PM EST sun Dec 8 2013
a weak system will move across the Ohio Valley tonight. High
pressure will attempt to build over the lower Ohio Valley...but
weak troughs will move across the eastern Great Lakes Monday and
again on Wednesday. A reinforcing surge of Arctic air will move
into the area middle week.
Near term /until 6 am Monday morning/...
on this update added a Winter Weather Advisory for the rest of
Northern Ohio mainly for a mix of light freezing rain and freezing
drizzle. Since most areas except Northwest Ohio won't get much snow the
freezing drizzle will make things slick. Temperatures may warm
above freezing after midnight along the Lakeshore.
deeper moisture exiting the area along with the patches of light
snow that have been reported here and there this afternoon. With
low level moisture remaining and light lift from a weak cold front
that will cross the area toward morning...area will remain at the
risk of developing light freezing rain and or freezing drizzle.
Quantitative precipitation forecast amounts very light. Have left advisory as is...this area has
the best chance of a light glaze of ice. Areas west of the
advisory may still see some light snow if they can maintain
saturation deep enough for ice nuclei. Any freezing rain/drizzle
will be very isolated. Little or no snow accumulation.
Temperatures will hold steady or even rise a few degrees
overnight...but they will still hold at or below freezing.
Short term /6 am Monday morning through Wednesday night/...
any light lingering precipitation will be exiting east Monday
morning. Temperatures at this Point May start to get above
freezing for NE Ohio and Lakeshore areas of northwest PA and therefore have
liquid drizzle. With Post frontal cold air
advection...temperatures will be steady or slowly fall.
We will incrementally get colder going into midweek. High pressure
will remain nearly stationary across the lower Ohio Valley...but
re-enforcing shots of cold air will be brought in with troughs
crossing the Great Lakes. Attention then turns to chances for lake
effect. Winds will fluctuate with these subtle features crossing
the lake and therefore at this point in time cannot narrow down
exact locations/times for the best snow. Made only minor
adjustments to the forecast for the lake effect.
Skies will stay mostly cloudy through the period with ample
trapped low level moisture. Only hope would be Wednesday night as
the high builds more into Ohio. Temperatures will struggle in the
20s for daytime highs and teens will be common at night. Still
will likely see locations with single digits by middle week.
Long term /Thursday through Sunday/...
Arctic high pressure will slide east late in the week and a return
south flow will develop. Do not look for an immediate warm up as
most of the country east of The Rockies will be trying to moderate
from the Arctic air mass...but we could see temperatures try to
recover to freezing by the end of the week. Some lake effect snow
will probably linger on Thursday although with the air mass very dry
and the surface high building in...anything significant should be
The models differ by the weekend with the European model (ecmwf) very fast with the
next front...dropping across the area backdoor style by Friday
night. Most of the other models including the European model (ecmwf) ensembles are
slower. A storm system is expected to develop somewhere over the
southeast states. The models do very poorly with these deepening
long wave troughs and surface features. Another chunk of Arctic air
is dropping out of Canada so there is wide margin of error in the
forecast by next weekend. For now...will forecast a small chance of
snow and temperatures near freezing on Saturday...then colder on
Aviation /00z Monday through Friday/...
low clouds and sprinkles of mixed wintry precipitation will continue to
spread over the area through midnight then just patchy fzdz late
tonight into early Monday morning. Conditions as most sites should drop
to IFR or low MVFR over the next 6 hours...then hang around until
the cold front pushes west to east across the area between 10z and
15z to cause ceilings to lift a little a few hours after the front has
passed. Some snow showers could start to affect eri toward 00z Monday
West-southwest winds will increase into Monday afternoon as colder air pushes into
the area with gusts around 25 knots over the northwest half of the area
during the afternoon.
Outlook...non VFR conditions will linger at times through
Thursday...mainly over NE Ohio/northwest PA.
winds will veer from east to south tonight and then west-southwest
on Monday as weak low pressure and then a cold front move across
Lake Erie. Decent cold advection develops on Monday. The pressure
gradient will tighten as the surface low deepens over Quebec... and
wind will increase to near 30 knots by late Monday as Arctic high
pressure spreads across the Great Lakes. Another surge of southwest
wind is expected later Tuesday as a clipper low pressure crosses the
northern Great Lakes. Winds will gradually diminish the second half
of the week but the gradient will remain rather strong and small
craft advisories will likely remain posted from Monday until
sometime Friday at which time high pressure may get near enough to
settle things. Ice will likely begin to develop on the western basin
of the lake this week.
Ohio...Winter Weather Advisory until 9 am EST Monday for ohz010>014-
Winter Weather Advisory until 4 am EST Monday for ohz003-
PA...Winter Weather Advisory until 9 am EST Monday for paz001>003.