Scientific Forecaster Discussion
fxus61 kcle 201144
Area forecast discussion
National Weather Service Cleveland Ohio
644 am EST Wed Nov 20 2019
high pressure will build east across the region today and
tonight. Low pressure will move northeast through the Great
Lakes Thursday and Thursday night, forcing a cold front east
across the area. After a secondary cold front moves east through
the lower Great Lakes Friday, high pressure will build into the
area from the west through Friday night. Low pressure will track
northeast through the Ohio Valley Saturday and Saturday night.
Near term /through Thursday/...
minor adjustments to pops and sky cover. Significant clearing
being observed across the western half of the area, but clouds
appear to be quickly building back into the area from the west.
This will allow for a period of mostly clear/partly cloudy skies
this morning. Also changed any rain showers across northeast Ohio
and northwest PA this morning to drizzle given observations and
lingering inversion-trapped low clouds remain across parts of
the area this morning, with a few patches of drizzle or light
rain showers in northwest PA. The western part of the area will
start out with clear skies, but should see some increase in
cloud cover through the morning. We will see a general slow
scattering of clouds through the remainder of the day, with an
end to any lake enhanced precip by this afternoon as high
pressure builds northeast across the area. Highs today will be
in the low to mid 40s. Lows tonight will range from the low 30s
east to the mid 30s west.
Low pressure will deepen and track northeast from the Central
Plains through the central Great Lakes on Thursday. A warm front
will lift northeast through the area in the morning, with a few
warm advection showers skirting the western half of the area
during the late morning and afternoon. Conditions will be breezy
in the warm sector with wind gusts in the 30-35 mph range during
the afternoon. Highs will reach the low to mid 50s across the
area, with upper 40s across northwest PA.
Short term /Thursday night through Saturday night/...
winds will remain up into Thursday night ahead of a cold front. A 40-
50 knot low level jet will be overhead ahead of the front at 925mb
which may result in wind gusts of 30 to possibly 40 mph. The front
is expected to arrive after midnight but the ridge quickly builds in
from the west and expecting the strongest gusts do be during the
evening hours. The exception is closer to the northeast Lakeshore
where the flow shifts onshore early Friday morning with winds
peaking in the 4-8 am window. Light showers will accompany the front
with conditions drying out quickly on Friday as high pressure builds
east across Lake Erie.
Models are starting to come into better agreement by Saturday with
both the 00z European model (ecmwf) and GFS showing a low pressure system developing
along the Gulf Coast and tracking northeast towards Pittsburgh
before energy shifts to the East Coast. This is ahead of an upper
level trough moving through the southern stream that attempts to
become negatively tilted as it lifts towards the Great Lakes region.
Given the strength of the upper level trough, will lean towards the
more northern solutions and have raised pops Saturday afternoon and
night. Precipitation is expected to fall as rain during the day on
Saturday with a brief transition over to snow as the system starts
to pull away and colder air is wrapped in from the west. We will be
keeping an eye on timing of the change over heading into Saturday
Long term /Sunday through Tuesday/...
below normal temperatures remain through the weekend with a gradual
upward trend towards normal during the first part of next week.
Sunday is expected to be mostly dry aside from a few lingering
showers across the snowbelt. High pressure will expand north up the
Ohio Valley on Monday. Interesting to note a shift with the 00z
European model (ecmwf) away from the stronger system tracking out of the plains
towards Wednesday. This run of the European model (ecmwf) keeps the flow more
progressive and is not as deep with the trough over The Rockies that
evolves into our mid-week system. Given the faster solution could
see chances of precipitation return as early as Tuesday. Confidence
is below normal in the forecast by day 7.
Aviation /12z Wednesday through Sunday/...
low level moisture trapped under an inversion will keep ceilings
around through parts of the period as high pressure build
northeast across the region. Some early clearing at western
sites will fill back in, with MVFR/VFR ceilings generally
expected through the day. A few spots of IFR will be possible
early, but generally improving after 14z. Winds will be light
through the period, and generally out of the west early becoming
Outlook...non-VFR possible Thursday and Friday with widespread
good marine conditions will continue today as high pressure builds
east across Lake Erie. On Thursday a low pressure system tracking
out of the plains will strengthen as it tracks northeast across the
central Great Lakes. Southerly winds on Lake Erie will ramp up
during the day on Thursday becoming southwest to 30 knots Thursday
night. Winds may approach gale force for a brief window on Thursday
night given very strong winds aloft. Small craft advisories will
likely be needed for the whole lake on Thursday night, continuing
from Lorain eastward during the day on Friday. Conditions will
improve by Friday night as a ridge builds over Lake Erie but another
low pressure system will track northeast up the Ohio Valley towards
Pittsburgh bringing on Saturday. Winds will increase as this system
pulls away Saturday night into Sunday with another window of choppy
conditions and 2 to 4 foot waves.