Scientific Forecaster Discussion
fxus61 kcle 201416
Area forecast discussion
National Weather Service Cleveland Ohio
916 am EST Sat Jan 20 2018
a large area of high pressure centered over the southeastern
states will slowly move off the coast this weekend and provide a
south flow and warmer temperatures across the area. Low
pressure from Colorado will track to the western Great Lakes on
Monday with the associated cold front sweeping across the local
area Monday evening. High pressure will build in from the west
through the middle of next week with seasonable temperatures.
Near term /through Sunday/...
have nudged temps up slightly based on current readings and made
minor adjustments to the sky cover.
Previous...a series of weak short waves will slide across
eastern Canada today with a weak surface trough dropping across
the eastern Great Lakes. The persistent south-southwest flow in the boundary
flow will continue but we should gradually lose the higher wind
gusts as the pressure gradient decreases. Deeper moisture is
creeping north. This will eventually lead to high clouds being
replaced by a stratus/stratocumulus deck. The first push of
stratocumulus appears destined to slide across the mid Ohio
Valley and WV this morning. The next push, the batch of lower
clouds moving north across Arkansas and eastern OK, should reach
the Route 30 counties from Findlay to Marion to mfd around mid
afternoon. This is more in line with the latest models which are
a bit slower than the guidance from Friday afternoon and seems
to line up with extrapolation. High temperatures are tricky. 850
mb temps are warm but clouds will increase and the south wind
will decrease. Given that we are starting fairly warm this
morning will forecast the higher end of guidance, with highs
Weak upward motion is progged to develop tonight as frontogenetic
forcing increases. Virtually all of the upward motion is progged to
occur in the lowest 10k and model soundings show a lack of deep
moisture. Will forecast a chance/slight chance of light rain or
drizzle, not expecting any significant rain. The gradient will relax
by tonight and it is possible that surface temperatures will drop
below freezing, mainly in eastern Erie and Crawford County, PA and
will mention a chance of freezing drizzle there. Elsewhere,
temperatures will not drop much tonight with lows in the 30s.
It will be hard to shake the clouds on Sunday and light rain
and drizzle will probably continue from time to time. The snow
will melt completely as dew points go above freezing and remain
above freezing through Monday. Forecast temps will be a bit
conservative on Sunday for now with highs generally in the lower
and mid 40s. Highs
Short term /Sunday night through Tuesday night/...
the short term begins Sunday night with models showing low pressure
in the Kansas with a warm front that loops just north of Ohio and
possibly into either northeast Ohio or nwrn PA. Will have chance pops
for most of the area although will have likely northwest in
increasing moisture and overrunning across the region through the
night. Monday the low will move to nrn Illinois/srn WI lifting the warm
front further north. A weak cold front/surface trough extending
well east from the wrapped up surface low will cross the region
during the day. While not much of an initial cool down expect it
will provide enough low level forcing for precip so will have likely
pops east and categorical pops west for the afternoon. The low will
continue northeast into the central Great Lakes by 12z Tuesday and
to eastern Quebec 12z Wednesday. Colder air will move into the
region behind the second cold front Tuesday as the low moves through
the lakes. Drying moves in for Wednesday however 850mb temps cool
from about -8c Tuesday evening to -14c by Wednesday morning so will
continue with snow showers especially northeast Ohio and nwrn PA.
Long term /Wednesday through Friday/...
Thursday high pressure moves through the Ohio Vly leading to a warm up
Friday and Saturday in swly flow as the high moves off the mid
Atlantic coast. Aside from lingering snow showers Wednesday night
off the lake, will have a dry forecast Thursday and Friday.
Aviation /12z Saturday through Wednesday/...
VFR conditions will persist into afternoon before warm advection MVFR
stratus develops/moves in from the southwest. Could begin as a
low VFR deck but will then lower early evening. Ceilings will
likely lower to IFR tonight and some drizzle could occur as a
warm front develops.
Outlook...non-VFR much of the time Sunday through Tuesday. Gusty
winds Monday night and Tuesday.
no headlines expected through the forecast period. South to
southwest flow will dominate today through Sunday as high pressure
moves to the mid Atlantic coast and low pressure moves into the
Central Plains. Speeds will be 15 to 20 knots today but should
diminish tonight through Sunday. Monday winds will turn southeast
and increase to 10 to 20 knots as low pressure moves across Iowa to
near Chicago. Tuesday winds turn southwest and increase to about 20
to 25 knots as the low tracks across the Central Lakes. Wednesday
look for west flow around 15 knots as high pressure builds from the