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fxus61 kcle 171100 
afdcle

Area forecast discussion
National Weather Service Cleveland Ohio
600 am EST Fri Nov 17 2017

Synopsis...
high pressure centered over the Great Lakes will shift to the East
Coast today, allowing a warm front to lift NE across the area late
tonight. A strong low pressure system will track across the lower
lakes Saturday, dragging an Arctic front across the forecast
area.

&&

Near term /until 6 PM this evening/...
no significant changes for the 630 update.

Original discussion...
dirty ridge centered over the Great Lakes will continue to
slide east and move off the East Coast this evening. Overcast
skies extend west into Illinois. As high shifts east will see
some sun breaks as clouds gradually mix out this afternoon. But
by then mid to upper level clouds will spread over the area
ahead of approaching warm front. Expect temps to warm into the
mid to upper 40s today.

&&

Short term /6 PM this evening through Monday night/...
models continue in good agreement with intense low developing in the
plains then tracking across the lower lakes Saturday. Tonight as
the low tracks NE it will lift a warm front, now across the lower
Mississippi Valley, across the area late tonight into Saturday
morning. Rain showers will spread NE across the forecast area
overnight.

Low tracks across the lower lakes Saturday. Nice ll jet develops
ahead of the system as the 850mb winds increase to 50-70 knots by
daybreak Saturday. Definitely enough lift to produce some
thunderstorms. Expect widespread rain showers with temperatures
warming into the 50s ahead of the Arctic front.

The sharp trough will cross the eastern Great Lakes Saturday night
and early Sunday. The deepening surface low will likely track just
north of Lake Erie with the boundary flow becoming northwest behind
the cold front. Winds may exceed Wind Advisory criteria for a while
Saturday night near Lake Erie. Strong to moderate cold advection is
progged but it will take until the wee hours of the morning on
Sunday to get cold enough for snow and perhaps not cold enough at
the immediate Lakeshore. The main short wave will be shifting east
of the area Sunday morning and subsidence will increase. This leaves
a relatively small window of opportunity for any heavier lake
enhanced snow early Sunday.

A second short wave is progged to drop across the eastern lakes late
Sunday and the lake effect will flare back up, aided by some colder
air aloft. The northwest flow would favor the inland areas of the
snow belt Sunday but winds will likely back to west and southwest by
Monday morning. This may place the better snow bands along the
Lakeshore and the city of Erie for a time until the lake snow shifts
northeast on Monday.

Temperatures will begin to moderate on Monday as ridging increases
with highs in the 40s across northwest and north central Ohio.

&&

Long term /Tuesday through Thursday/...
temperatures will continue to warm Monday night and Tuesday as the
south flow increases ahead of the next cold front. High temperatures
on Tuesday will approach or exceed 50. The models have been
consistent in generating very little moisture/precip with the front.

Temperatures will see saw back down Wednesday behind the front as
the next short wave sprints across the eastern Great Lakes. Some
lake effect snow is likely but subsidence will increase quickly as
high pressure will build in by Thursday. The flow aloft will become
more zonal until the next short wave drops across the lakes at the
end of the week. Temperatures will remain somewhat below normal.

&&

Aviation /06z Friday through Tuesday/...
dirty ridge centered over the Great Lakes will drift to the East
Coast by evening. MVFR stratus deck will improve to VFR by early
afternoon then start to scatter out by late afternoon.

Outlook...non-VFR returns tonight through Saturday in -shra.
Thunderstorms possible late Friday night and Saturday as Arctic
front moves across forecast area. Rain changes to snow early
Sunday morning. Lake effect snow showers develops in the
snowbelt Sunday and lingers into Monday.

&&

Marine...
the northwest flow is winding down on Lake Erie and winds will veer
to the north this morning, then gradually become southerly as the
ridge axis moves east of the lakes.

The south flow will increase significantly tonight as low pressure
deepens over the Midwest. The surface low will continue to deepen on
Saturday and will track near Lake Erie Saturday afternoon/evening,
probably just to the north of the lake. South winds will become
southwest and low water is likely on the western basin. Winds will
become west northwest as the low passes by and the associated cold
front sweeps across the lake at which time gale force winds will
develop late Saturday. The gales will continue into early Sunday on
Western Lake Erie and Sunday afternoon on Eastern Lake Erie.

The northwest flow will diminish to 15 to 20 knots or so Sunday and
Sunday night and back to the southwest on Monday. The next cold
front is due later Tuesday. Small craft advisories will be needed.

&&

Cle watches/warnings/advisories...
Ohio...none.
PA...none.
Marine...gale watch from Saturday evening through Sunday afternoon for
lez145>149-165>169.
Gale watch from Saturday afternoon through Sunday morning for
lez142>144-162>164.

&&

$$
Synopsis...djb
near term...djb

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