Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
419 am EST Tuesday Dec 1 2015
low pressure over Minnesota early this morning will slowly weaken
as it moves eastward into the central Great Lakes by Wednesday
morning. An occluded front is expected to sweep across the region
this afternoon and evening. On Wednesday a trough of low pressure
will slide across the area. High pressure will build in Thursday
Near term /until 6 PM this evening/...
models have slowed the movement of the warm front northward into
the area. It is currently located to the south of the Ohio River.
This boundary will lift northward this morning with areas of
drizzle eventually expanding to showers as it gets closer.
Believe the showers will increase across the eastern half to
2/3rds of the area by late morning then slowly move eastward
through the afternoon as the occluded boundary moves eastward
across the region. There has been a few rumbles of thunder across
Illinois but believe this better lift/instability will lift more
into Michigan so have kept its mention from the forecast at this
time. If any thunder occurs in the County Warning Area it will
likely be across Northwest Ohio.
Temperatures are expected to warm into the 50s with much of the
region briefly getting into the warm sector.
Short term /6 PM this evening through Friday night/...
only eastern portions of the County Warning Area (cwa) will still
be under the showers by 6pm. All of the showers should clear the
County Warning Area by midnight with the frontal boundary well to our east. A
period of dry conditions is expected into Wednesday morning as we
await the arrival of the upper level low from the western Great
Lakes. As the low approaches it will attempt to pull some moisture
westward to near the Ohio/PA border. Have introduced some chance
probability of precipitation to cover for this potential. Lift with the upper level low
will be enough to generate chances of showers Wednesday afternoon
for the entire region. As the colder air arrives Wednesday
evening we should be able to change the rain over to snow from
west to east. The colder air spilling across Lake Erie will pick
up some additional moisture Wednesday evening into the overnight
hours. It may take some time to change it over to all snow
Wednesday night with the main impacts being the higher terrain of
NE Ohio and northwest PA. Have placed some light accumulations of snow for
the hills with 1 to 2 inches possible. Northern Geauga County
along with portions of Erie and Crawford counties in northwest PA could
see these higher amounts. The lake effect snow may linger into
Thursday afternoon across northwest PA but any accumulating snow will
end. Drier air takes over Friday with high pressure taking control
of the region.
Cooler on Wednesday but highs should be very close to seasonal
averages. Thursday will likely be the coolest day in the wake of
the low with highs in the lower 40s. Where the snow has
accumulated through Thursday morning highs will likely stay in
the 30s. More sunshine on Friday will warm highs back into the
lower and middle 40s.
Long term /Saturday through Monday/...
beautiful weekend coming up with high pressure at the surface and a
strong amplified ridge aloft. Only one shortwave coming across the
northern tier of states to the Great Lakes on Sunday tries to
dislodge the ridge. This feature is dry and at most it would knock
off a couple of degrees from highs and bring a few clouds to the
area late in the weekend. Differences on timing of a cut off upper
low across the Southern Plains and its shift eastward early next
work week. Kept forecast dry through Monday night. Temperatures
through the period will be within a few degrees of 50 each day...and
near freezing/middle 30s at night.
Aviation /06z Tuesday through Saturday/...
widespread IFR/LIFR ceilings will spread northeast across the entire
area overnight...ahead of an occluded front that will move across
the forecast area Tuesday afternoon. Expect widespread IFR/LIFR
Tuesday morning...slowly improving from the west tomorrow
afternoon behind the front.
Outlook...widespread IFR/LIFR ceilings Tuesday...with some improvement
Tuesday night in dry slot. Non VFR continues Wednesday into
Wednesday night in widespread synoptic -sn. Lake effect snow
showers probable NE Ohio/northwest PA Thursday.
occluded front to cross the lake today...with winds coming around
to the southeast ahead of it and a sharp shift to the west in its
wake. Speeds will hold between 10 and 20 knots. Winds slack off
late tonight with some brief ridging...but the low from todays
system will slide east across the lake on Wednesday. Winds are
expected to kick up some as the low gets absorbed into low
pressure off of the New England coast and high pressure builds
across the lower Ohio Valley and western lakes. There will be a
period of west winds around 20 knots Wednesday night and Thursday
that may be able to trigger a Small Craft Advisory...2 to 4 feet
might hold it. Then for Friday and Saturday high pressure will be
across the region and winds will generally be from the southwest
at 5 to 15 knots.