Area Forecast Discussion
Issued by NWS Cleveland, OH

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000
FXUS61 KCLE 021144
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
644 AM EST Fri Dec 2 2016

.SYNOPSIS...
Low pressure across the eastern Great Lakes will depart to the east
tonight as high pressure builds in from the west. The high will move
east over the weekend, reaching New England by Sunday evening. A
weak warm front will lift north across the area Sunday night with
high pressure building east across the Ohio Valley on Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Lake effect showers continue off the east end of the lake and have
been focused into Pennsylvania for the last couple hours. Radar is
not fully capturing the intensity and have even observed a few
thunderstorms. Precipitation type remains tricky with lakeshore
areas warm enough to just be rain while the higher inland areas are
mostly snow. Even where the snow is falling, dewpoints are near the
freezing mark and web cams have shown snow having a hard time
sticking to roads. That may be starting to change within the heavier
band where the boundary layer continues to cool as snow melts. Did
include isolated thunderstorms this morning with a few more inches
still possible, mainly on grassy surfaces. Hopefully we will not end
up needing an advisory but will be looking for reports over the next
couple hours to verify.

The upper level low over eastern Canada will pivot southeast today
with a trough swinging through the eastern Great Lakes. Before that
occurs late this afternoon, we will maintain a westerly flow across
the lake with continued lake effect showers. The moisture depth
lowers to near 7000 feet towards mid-day with moisture depth
increasing again early this evening with the passage of the trough.
Expecting to see westerly lake effect bands flare up this morning
with good convergence along the eastern lakeshore before shifting
more inland late this afternoon into tonight. Precipitation type
during the daytime hours will trend back towards rain as
temperatures creep back up a few degrees. Some of the higher areas
in northwest PA may hold onto a rain/snow mix or even all snow but
expecting accumulation potential to drop off with temperatures at
least reaching the mid 30s.  Moisture depth drops off enough that we
may even start to lose ice crystals in the cloud layer.

Snow bands will shift inland as the prevailing flow becomes
northwesterly tonight with more of multi-band structure developing.
Precipitation type will trend back towards snow with lows expected
to dip into the lower 30s for all areas but the immediate lakeshore.
Minor accumulations are possible again with locally up to an inch in
Ohio and 1 to 3 additional inches in northwest Pennsylvania.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
High pressure builds in from the west on Saturday and moisture depth
decreases once again. Will hold onto chance pops across the snowbelt
in Ohio with higher pops lingering in northwest Pennsylvania through
at least the morning. West to northwest flow holds on through the
day and have kept skies mostly cloudy, even as the moisture depth
becomes thin in the west. Given the expected cloud cover, went below
guidance for highs on Saturday with most locations peaking in the
upper 30s.

High pressure will shift off to the east on Sunday as a fast moving
trough approaches from the plains. Next round of precipitation
arrives Sunday afternoon into Sunday evening as an elevated warm
front lifts through. Winds do flip around to the southwest by Monday
but temperatures will generally only warm a few degrees from
Sunday`s high.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
Long term period begins Tuesday with low pressure moving northeast
from the lower Ohio valley into the southern Great Lakes by Tuesday
night. Precip is expected to overspread the area as mainly rain,
with a rain/snow mix not out of the question in the higher terrain
of NW PA at the onset of the precip. There should be a lull in
precip across the area sometime during the day Wednesday between the
departing low and the next system to impact the region, but still
enough timing uncertainty to warrant slight chance pops. Slightly
above normal temps expected Tuesday and Wednesday with return flow
regime.

Attention turns to significant pattern change with a strong arctic
front moving through the region sometime in the Wednesday night
through Thursday night time frame. GFS remains the faster solution,
with more progressive mid/upper level pattern, with the ECMWF
western CONUS trough deeper/more amplified and resultant slower
cyclogenesis/fropa. Models are converging slightly, with a similar
surface low development/track along the front, albeit nearly 24
hours apart. Forecast reflects a blend of these two solutions,
however slightly favor timing of the GFS over the ECMWF. This will
result in colder temps Thursday falling into Friday, with currently
forecasted lows in the teens inland and around 20 near the lake
Thursday night. Both solutions also have a favorable lake effect
setup for the snowbelt behind the fropa despite the timing
difference, with favorable fetch, delta-Ts, synoptic influence and
moisture.

&&

.AVIATION /12Z Friday THROUGH Tuesday/...
Widespread VFR/MVFR stratus deck will continue to impact
terminals through the first half of the TAF period. West southwest
flow will slowly veer west through the day, with some gusts at or
above 20 kts possible. Lake effect rain showers will affect KERI
early in the period, and to a lesser extent KCLE and KYNG, where
only VCSH is warranted. Flow will veer northwest after 00Z, with
deteriorating ceilings downstream of Lake Erie, although only MVFR
conditions forecast at the moment.

OUTLOOK...Non-VFR cigs likely to continue into Saturday
with scattered rain and snow showers producing variable
conditions in the east part of the snowbelt.

&&

.MARINE...
West winds 20 to 25 knots will continue across the lake Friday
before veering northwest and diminishing to 15 to 20 knots Friday
night. Will extend the Small Craft Advisory on the western portion
of the lake through 10 PM tonight, with the eastern end of the lake
continuing through 10 AM Saturday. High pressure will build across
the Great Lakes Saturday, with winds diminishing to less than 10 kts
Saturday night. A mid level trough will swing through the Great
Lakes Sunday night, with winds south winds veering west 10 to 15
knots, however winds will subside again Monday as high pressure
builds back across the Great Lakes. Winds will back
east/southeasterly 10 to 20 knots by Tuesday as low pressure tracks
from the Mississippi valley towards the Great Lakes.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 10 AM EST Saturday for LEZ145>149.
     Small Craft Advisory until 10 PM EST this evening for
     LEZ142>144.

&&

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


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