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755
FXUS61 KCLE 182039
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
339 PM EST Mon Feb 18 2019

.SYNOPSIS...
High pressure over the northern Plains will build southeast
into the Great Lakes region tonight and Tuesday. Low pressure
over the southern Plains will move northeast into the central
Great Lakes by Wednesday night, eventually moving across
southern Quebec Thursday. High pressure will build back into
the region for Friday.

&&

.NEAR TERM /THROUGH TUESDAY/...
Trough lingering across northern Ohio through the morning but
was pulling east this afternoon and taking moisture with it.
Still, many area reporting light snow early this afternoon but
that should become more insignificant into late afternoon and
evening as drier air continues to move in from the north.
Stratus had moved out of northwest Ohio around noon but
increased sun and low level instability caused convective cu to
develop. For the evening expect clouds to continue to decrease
as high pressure and drier air move in and low level convective
cu dissipates. Tuesday will continue with a partly cloudy
forecast with broad high pressure across the area. Tuesday night
is beginning to look interesting as moisture lifts north into
the area ahead of low pressure moving north out of the lower
Mississippi Valley. Strong warm advection will develop through
the TN Vly and central Plains late Tuesday, eventually
developing across the local area mainly after midnight into
Wednesday transporting deep moisture into the area from the Gulf
Coast. Models bring this moisture in mainly after midnight
Tuesday night. Expect snow to move in from the south/southwest
after midnight reaching near a TOL-YNG line by 12Z. Looking at
BUFKIT, precip will be mostly snow but towards dawn Wednesday
would expect a mix with freezing rain far south cutting snow
accums as warmer air moves in aloft. For now will have 1 to 3
inches far south from Marion to Knox counties with around an
inch FDY to MFD.


&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Precip will be overspreading the region from the southwest on
Wednesday as low pressure approaches the western Great Lakes
from the southern Plains. An area of strong 925-700mb ascent
will work northeast along the Ohio valley on the edge of a
strong 50-70kt low level jet. Upper divergence will be
increasing across the Great Lakes region as a strengthening
upper jet works northeast into the region, at the entrance
region of a very strong zonal upper jet moving east over the
northern Atlantic. While the local area will be in between the
core of these two forcing mechanisms, there will be enough
mid/upper support for vertical ascent to warrant high
likely/categorical pops on Wednesday, although precipitation
amounts will be higher to the northwest and southeast of the
forecast area. Precipitation type will be somewhat of a
challenge until the attendant surface warm front lifts north
through the area by late Wednesday afternoon, however a fairly
isothermal sounding warming uniformly from the surface to the
mid levels suggests a fairly sharp transition from snow to rain,
although enough lag in surface temps may suggest a low impact
freezing rain threat for only a couple of hours from south to
north. Rain should be the predominant p-type after 18Z
Wednesday. The surface low will be near Lake Michigan by 00Z
with a lagging cold front/occlusion/trough lifting northeast
through the area from 03Z Thursday through 12Z. A large area of
high pressure will then build east across the Great Lakes region
Thursday through Friday, providing dry conditions and temps a
few degrees above normal. Highs will generally be in the low 40s
through the period. Low will be in the low 30s Wednesday night,
dropping into the low to mid 20s Thursday night.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
If you are paying attention to the large scale synoptic pattern, it
will appear to be looping on repeat by the time we get to the
weekend. This will be the third iteration in a weeks time of digging
western CONUS trough, downstream eastern CONUS ridge amplification,
accelerating upper jet rounding the trough and ejecting towards the
Great Lakes, surface cyclogenesis across the southern Plains lifting
into the Great Lakes, and low level return flow lifting moisture
into the region on the heels of a strengthening low level jet. What
does this all mean? Another area of precip is expected to lift
through the region this weekend. Ridging will move from the Great
Lakes into New England, keeping conditions dry Friday night, but
precip chances increase Saturday, with the best shot at precip of
Saturday night. Some lingering precip is possible Sunday as the low
lifts northeast out of the Great Lakes, but will generally be drying
by late Sunday night into Monday. The difference with this system is
that we will start out with warmer temperatures, with the onset of
precip looking to be mainly rain. Temps will rise into the upper 40s
to mid 50s Saturday and Sunday. Cooler air returns by Monday with
highs in the upper 30s.

&&

.AVIATION /18Z Monday THROUGH Saturday/...
Widespread MVFR Cigs to start this afternoon with light snow and
fog affecting most terminals dropping conditions to IFR at
times. satellite shows drier air dropping into the area from the
north which should tend to dry up the snow and lift CIGS. Will
start TOL terminal at VFR. Elsewhere hesitate to bring clearing
into the north shore as usually clouds hold tight to the
coastline through mid day before drier air overcomes coastal
lift so have shaded toward a more pessimistic MVFR afternoon.
There is a chance however that clearing does work in so will
continue to monitor for a more widespread VFR developing.
Overnight into Tuesday trend will be to VFR as high pressure
builds in.

OUTLOOK...Non-VFR possible Tuesday night into Thursday morning.

&&

.MARINE...
Quiet conditions expected on a mostly ice covered lake through the
middle of the week as high pressure moves across the region. A low
will pass northwest of the lake Wednesday night, with a warm front
lifting north and winds becoming southerly ahead of this system on
Wednesday. A cold front will quickly follow Wednesday night, with
winds becoming west southwest behind the front, generally 15-20 kts.
Winds will subside on Thursday as another high moves across the
region, with light and variable winds expected into the weekend.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.

&&

$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...Greenawalt
LONG TERM...Greenawalt
AVIATION...TK
MARINE...Greenawalt