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000
FXUS61 KCLE 090617
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
117 AM EST Mon Dec 9 2019

.SYNOPSIS...
A weakening cold front over southern Ontario will stall north of
the lake overnight as low pressure takes shape over the central
Plains. This deepening low pressure will move along the cold
front and should track across southern Ontario. A strong cold
front will move across the region Monday night. Colder air
arrives in the wake of the front with an upper level trough
lingering into Wednesday.

&&

.NEAR TERM /THROUGH TODAY/...
Latest regional radar currently shows some shower activity
finally moving into the central Mississippi Valley region at
this time. Expecting the rain to gradually move northeast
overnight toward the local area. Timing looks reasonable in
current forecast so will not make any major changes.

Previous Discussion...

Increasing southerly winds will assist in increasing the return
of low level moisture and bring warmer temperatures into the
region. Low pressure will deepen as it moves across the central
Mississippi River Valley. The increased warm advection ahead of
the low will help to produce a period of rainfall that that move
across the region from southwest to northeast last tonight into
Monday. The heaviest rainfall will be Monday morning/afternoon.
Increased cloud cover tonight and the warm advection will keep
lows in the 40s. Highs Monday afternoon should reach into the
lower to middle 50s. Winds will be gusty through the afternoon
but should remain below advisory levels.

The gusty winds continue into the night but believe the periods
of rain will keep the region from mixing too deep. However it
will be something for later shift to monitor. Otherwise expect
to see the showers decrease from west to east after midnight.
Cant rule out a mix with some snow as the precipitation ends,
but now accumulations expected. The cold front will cross the
area overnight with lows falling into the 30s.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
Minor forecast changes with the short term period, with a
slight downward trend in lake effect pops through the period. A
cold front will be east of the forecast area at the onset of the
period, as low pressure deepens northward through Quebec. The
flow behind this front will be west to southwest Tuesday into
Wednesday, with limited synoptic moisture outside of the 850mb
layer. Instability looks to be marginal in this period as well,
so backed down to low likely pops confined to northern Erie
county. A secondary front will veer winds more northwest late
Wednesday through Wednesday night, but very dry 850 mb air will
quickly move southeast across the Great Lakes, which should
curtail any appreciable accums across the local area. Ridging
will build northeast into the region overnight, which will
slowly bring an end to lake effect pops. Temperatures Tuesday
will remain steady or fall behind the front, with low 30s by the
afternoon. Highs on Wednesday will be in the upper 20s, with
the current forecast colder than guidance. Lows Wednesday night
will fall into the teens.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
High pressure will build east of the region Thursday, with a period
of prolonged Gulf return/WAA into the weekend. Moisture return
increases Saturday/Sunday, with a southern stream wave lifting
across the northeast CONUS and a northern stream wave moving into
the Great Lakes bringing increase pop chances, although synoptic
details lead to lower confidence at this point. Highs in the low 30s
Thursday will warm into the 40s for the weekend.

&&

.AVIATION /06Z Monday THROUGH Friday/...
Moisture will continue to increase across the region into Monday
with ceilings lowering to IFR at most sites by 14Z. A few
showers are possible prior to 12Z with widespread rain spreading
in from the west after 12Z. Rain will continue for much of the
day with MVFR visibilities common and brief periods of IFR in
heavier showers. Southerly winds will be breezy at times with
gusts of 20-25 knots late morning through the afternoon. Drier
air will wrap in from the west with a cold front during the
evening. Drier air will initially wrap in from Central Indiana
across Lake Erie with showers becoming more scattered during
the evening with gradual improvement to ceilings and
visibilities.

.OUTLOOK...Non-VFR ceilings continue into Tuesday then at ERI
Tuesday night with scattered snow showers Tuesday night. Non-
VFR returns at times with a cold front on Wednesday, lingering
into Thursday in NW PA.

&&

.MARINE...
Have extended the Small Craft Advisory through the night. Little
change is expected with the wind and downsloping will keep winds
around 20 knots for much of the night. Winds will generally
stay out of the south to southwest through Monday around 15-20
kts. A cold front crossing the lake Monday night into Tuesday
will likely prompt another Small Craft Advisory as winds become
westerly 20-25 kts. Winds decrease slightly Tuesday night but
ramp up again Wednesday into Wednesday night, as another front
crosses the lake. Winds become northwest behind this front into
Thursday, with a brief period of 25-30 kts possible Wednesday
night. Winds subside Thursday into Friday with high pressure
building across the lake.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory until 4 AM EST early this morning for
     LEZ149.

&&

$$
SYNOPSIS...MM
NEAR TERM...Lombardy/MM
SHORT TERM...Greenawalt
LONG TERM...Greenawalt
AVIATION...KEC
MARINE...Greenawalt/Oudeman