Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
307 am EST Wednesday Nov 26 2014
weak high pressure over the area will move northeast and dissipate
by this evening. Low pressure will move northeast along the East
Coast today through Thanksgiving day. High pressure will gradually
build east over the Ohio Valley by Friday morning and begin to push
the colder air out of the region. Low pressure will move into the
western Great Lakes by Saturday afternoon forcing a warm front to
lift north into the region. The low will move northeast to James Bay
by Sunday and force a cold front east across the area.
Near term /until 6 PM this evening/...
high pressure over the area will move northeast and weaken today as
low pressure begins to move north along the eastern sea board. The
storm system on the coast should throw back some moisture into the
extreme eastern portions of the forecast area. There is chance that
enough moisture will make it over the mountains to produce some
light snow or a mix of rain and snow over the extreme east.
Storm system will pull out to the northeast this evening and take
the precipitation with it.
Surface troughiness will linger over the region today from the low
pressure system. Clouds will struggle to clear out through the day
due to the low level moisture lingering around. Some of the moisture
tries to dissipate this morning but East Coast low reinforces the
low level moisture so it is going no where. Expecting mostly cloudy
skies through the day across the entire forecast area.
Temperatures will struggle to climb into the 30s as weak cold air
One concern I do have is potential for some reverse lake effect
developing on the lake this afternoon. Flow is expected to become
well aligned during the afternoon out of the northeast and this
could send a Few Lake effect rain/snow showers into the Toledo area.
Will add a slight chance of rain/snow for that area this afternoon.
Short term /6 PM this evening through Saturday night/...
upper level troughiness will move east across the eastern United
States Thanksgiving day into the weekend resulting in some unsettled
weather during the first half of the Holiday weekend. Very broad
upper level ridge will begin to shift east toward the forecast area
as we approach the weekend.
Flow begins to shift around late Thanksgiving day to a more westerly
and then northwesterly direction for lake effect to develop. This
should set the stage for some snow shower activity across northeast
Ohio and northwest Pennsylvania. Instability by Thursday afternoon
and Thursday night is conditional in other words weak at best.
Although inversion lifts to over 10k feet Thursday afternoon into
Thursday night. Looking at storm totals through Friday around 3
inches in Crawford and Erie counties of Pennsylvania. Further
west...little or no snow accumulation expected.
Some of the higher snow totals will likely come from lake effect
that is expected to develop on Thanksgiving day in the northwest
Temperatures will bottom out on Thursday and then begin to recover
on Saturday a high pressure will gradually shift east of the
A storm system approaches the western Great Lakes by Friday forcing
a warm front to lift northeast across the region on Saturday.
Temperatures expected to climb well into the 40s on Saturday for
Long term /Sunday through Tuesday/...
not many changes to the long term this morning. The new 00z models
are in fair agreement during the period. Warm air advection showers
will likely be ongoing at the start of the period. A strong cold
front is still on track to cross the region Sunday night. The
showers will persist into Monday morning and then quickly end from
northwest to southeast during the day. It will take some time for temperatures to get
cold enough for a transition to snow and think most of the precipitation
will fall as rainfall. High pressure will build over the region
from the north Monday afternoon through Tuesday. 850 mb temperatures will
dip to around negative 6 but the airmass will be very dry so not
expecting much if any lake effect given an unfavorable flow. Temperatures
Sunday will average above normal with seasonable temperatures expected both
Monday and Tuesday behind the cold front.
Aviation /06z Wednesday through Sunday/...
expect widespread stratus deck ovc015-030 to remain through the
overnight hours. Clouds across NE Ohio eroding as cirrus deck moves
over area...but latest hrr models shows stratus deck scattering
out for a short time then filling back in toward daybreak. Did not
mention -sn across NE Ohio today as doubts as whether the precipitation
across Virginia will make it that far north. If it does reach NE
Ohio doubt that it would be much worse than flurries.
Outlook...non VFR developing Thursday in -sn...lingering across
far NE Ohio/northwest PA into Friday. Non-VFR Sunday in -shra with the next
the next couple of days will be quiet on the lake as weak high
pressure builds over the region. A cold front will eventually cross
the lake Thursday night causing the flow to become northwest and
increase a little. Will probably need a small craft for the east
1/2 to 2/3 of the lake. The small craft should be short lived as a
surface ridge will cross the lake on Friday. This will cause S to
SW flow to return to the lake. Speeds will gradually increase over
the weekend but little change in direction is expected till a cold
front crosses the lake Sunday evening and night. The frontal
passage will signal a chance back to northwest flow with more small
craft headlines likely.