Scientific Forecaster Discussion
fxus61 kcle 180256
Area forecast discussion
National Weather Service Cleveland Ohio
956 PM EST sun Nov 17 2019
a weak upper level trough will move across the Great
Lakes region on Monday. A weak front will move across the area
Monday and Monday night. High pressure will build back in for the
middle of the week. Another cold front will move across the region
Thursday night. High pressure builds back in for next weekend.
Near term /through Monday night/...
sprinkle chances have just about passed the Toledo area. While
cannot rule it our anywhere else across north central Ohio
overnight, it is very unlikely. Have raised lows by a degree or
two with the cloud cover helping keep it somewhat warmer.
Otherwise no other changes with this mid evening update.
Previous discussion follows.
A complex and moisture starved upper level trough will move across
the Great Lakes region and upper Ohio Valley tonight through Monday.
Generally this system will not bring much weather to the area with
only high and mid level cloudiness on the increase for today into
tonight. High and mid level cloudiness will continue on Monday.
Moisture is very limited and measurable precip is not expected but
can't rule out a few sprinkles tonight into tomorrow. Surface winds
will be weak with light and variable winds expected tonight into
Monday as well.
The surface and mid level flow becomes westerly by Monday evening
and Monday night. The westerly flow over Lake Erie will be weak but
850 mb temperatures cool off down to around -5c Monday night. There
could be some scattered unorganized lake effect rain showers and
snow showers that develop late Monday night for the primary snowbelt
areas of far northeast Ohio and northwest Pennsylvania. Precip will
be very light. Forecast soundings are showing the possibility of
some patchy drizzle as well Monday night with some low level
moisture returning and some lift in this shallow layer. Not
confident enough yet to have in the forecast but something to keep
an eye on.
Short term /Tuesday through Wednesday night/...
a series of shortwave troughs are expected to rotate through the
backside of a large upper level trough situated over the eastern
Continental U.S.. with some low-level moisture still present over the lower
Great Lakes, this series of shortwave troughs will provide enough
lift for widespread rain showers Tuesday afternoon transitions into
mixed lake effect precipitation Tuesday night for northeast Ohio and
northwest Pennsylvania. This will transition back to lake effect
rain Wednesday afternoon before diminishing as dry air at the upper
level ridge moves in Wednesday night. At the surface, a large high
pressure develops over the southeast Continental U.S. And Ohio Valley and
builds northeast Wednesday night. A warm front extending from low
pressure over the Central Plains will move north across the area,
inducing southerly flow Wednesday night. Temperatures will remain
slightly below normal through this period until that southerly flow
Long term /Thursday through Sunday/...
southerly flow will intensify on Thursday afternoon with strong warm
air advection encompassing the entire forecast area. This will
result in sustained winds of 15 to 20 knots with gusts up to 25
knots Thursday afternoon. Will will also result in above normal
temperatures for the first time in a long while. The aforementioned
low pressure is expected to deepen as it moves northeast across the
central Great Lakes with a cold front quickly moving east across the
forecast area on Thursday evening into Thursday night. Widespread
rain will overcome the area ahead and behind this cold front
beginning late Thursday morning through late Thursday night. This
will transition to lake effect rain showers on Friday lasting
through and slowly transitioning to a rain/snow mix late Friday
afternoon and then all snow late Friday night. Following the cold
frontal passage on Thursday night, temperatures will go back to
below normal through the end of the forecast period.
Aviation /00z Monday through Friday/...
with this forecast package did include a bit of morning br for
tol/fdy. As low level moisture increases, this may result in
some brief interruption to vsby. Otherwise ceilings will remain
VFR except some MVFR making its way to eri late Monday afternoon
and cle after 00z Tuesday. Winds will be light/variable although eri
should maintain southeast flow for tonight.
Outlook...non-VFR likely Monday night through Tuesday night.
Non-VFR possible again Friday.
quiet conditions will continue on Lake Erie with winds at or below
15 knots and waves at or below 4 feet through at least Wednesday
night. The next storm system to have a notable impact on Lake Erie
beginning Wednesday night. A warm front associated with a deepening
low pressure will move north across Lake Erie late Wednesday night
inducing a southerly wind strengthening to 20 to 25 knots by
Thursday afternoon with gusts as high as 35 knots. A Small Craft
Advisory for winds 20 knots or greater may be needed at this point.
A cold front will move through Thursday evening quickly veering
winds to out of the west and northwest, with elevated winds
continuing through Thursday night. Northwest winds of 15 to 20 knots
will continue through at least Friday night, likely inducing Small
Craft Advisory conditions for nearshore zones east of the islands
through Friday night.