000
FXUS63 KAPX 010207
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1007 PM EDT Sat Oct 31 2020

.UPDATE...
Issued at 1000 PM EDT Sat Oct 31 2020

Maturing cold front making steady east progress into eastern
Wisconsin this evening, with sharpening shortwave trough driving
this front digging into northern Minnesota. Strong deep layer
forcing working on a modestly moist environment will help rain
expand along this front as it works into our area later this
evening/early overnight. Attention then turns to intense post-
frontal cold air advection and the development of lake processes
heading into early Sunday morning. Best lake effect looks to hold
off until after sunrise, but still expect some decent lake shower
organization toward morning. Rapidly shrinking melting layer will
result in a transition to more snow toward sunrise, especially
away from the immediate coastal areas. Some slushy light
accumulations are expected...with more significant snow into the
day Sunday. Gusty pre-frontal southwest winds turn west and
northwest overnight and Sunday, further increasing in speed as
pressure gradient becomes maximized and mixing deepens. No changes
to inherited headlines at this time.

&&

.NEAR TERM...(Through Sunday)
Issued at 210 PM EDT Sat Oct 31 2020

...Gusty winds and snow...

High Impact Weather Potential...Hazardous driving conditions and
Lakeshore flooding Sunday.

Pattern Synopsis/Forecast...Upper ridge over the Great
Lakes/Midwest moves quickly east today. Sharp trough drops into
the area Sunday with closed upper low developing in the trough.

At the surface, low pressure was centered over Ontario with a cold
front extending south through the Central Plains. A warm front
extended from Wisconsin into the Ohio Valley. The warm front moves
across MI this afternoon and the cold front reaches Lake Michigan
late this evening and moves through our region overnight.

The pressure gradient tightens up significantly overnight as 850mb
winds are expected to rise to 50kts and 850mb temps drop to
around -10C Sunday. This creates two problems strong winds mixing
down to the surface and lake effect snow developing as delta Ts
reach 20F during the day Sunday.

Primary Forecast Concerns...Primary concerns are precipitation
onset, and snow and wind hazards Sunday.

Precipitation Onset

Rain ahead of the cold front reaches the Eastern U.P. around 8pm and
the Lake Michigan shoreline around 10pm and Lake Huron shoreline by
2am. Temperatures will remain in the 40s past midnight. Once the
cold front moves through in the very early morning hours, the
precipitation becomes more showery.

Snow

Enough cold air moves in by daybreak that the precipitation will
change to or mix with snow showers in all areas except near the
lakeshores. Lake effect snow showers then continue through the day
Sunday with the most snow falling from areas near Gaylord south to
Cadillac and Lake City, also W Chippewa in a northwest flow.
Right now we are looking at accumulations up to around 5 inches in
the northwest flow snowbelt areas.

Winds/Lakeshore flooding

The bigger problem will be the very strong winds Sunday especially
for the counties along the Lake Michigan shoreline where gusts to 50
mph are possible around midday. Worst than normal lakeshore flooding
will be a problem as well in those areas. Inland gusts to 40 mph are
possible.

Impacts

Blowing snow, reduced visibilities, and slushy road surface will be
the result of the snow and winds, creating hazardous driving
conditions at times Sunday.

Lakeshore flooding and dangerous waves are expected on area
shorelines Sunday. Waves over 10 feet will inundate shoreline areas
and create hazards on piers and breakwaters.

In addition, 50 mph winds can bring down tree limbs and move objects
that are not tied down. High profile vehicles will have much
difficulty driving. Power outages are possible.

&&

.SHORT TERM...(Sunday night through Tuesday)
Issued at 423 PM EDT Sat Oct 31 2020

...Remaining Windy but Snow Ending...

High impact weather: Blowing and drifting snow into the evening.

Primary forecast concerns/challenges: Ending of pops and wind
speeds.

Northwest flow lake effect snow showers will continue into the
evening with an additional inch or so possible in favored areas
(mainly along and west of Interstate 75). Drier air/waning over lake
instability should then diminish activity overnight. Warm advection
Monday on through the remainder of the forecast should lead to
moderating temperatures Monday and milder readings Tuesday. Highs
Monday in the low and mid 40s then the mid 40s to around 50 Tuesday.
Lows in the mid and upper 20s. Northwest winds will continue to
gust to between 30 and 35 mph into Sunday evening leading to
additional blowing and drifting snow with winds slowly
diminishing overnight. Westerly winds will pick up again during
the day Monday with gusts to 30 mph then slowly diminish Monday
evening and overnight.

.LONG TERM...(Tuesday night through Saturday)
Issued at 423 PM EDT Sat Oct 31 2020

...Warming Trend...

High impact weather: None is expected.

Extended models pretty much all continue to advertise increasing
ridging/warming through the week. So no precipitation and
unseasonably mild temperatures are expected through the entire long
term forecast. Highs of well into the 50s to the low and possibly
even a few mid 60s are forecast. Lows in the upper 30s and 40s. The
unseasonable warmth looks like it will extend through next weekend
and possibly even into the early part of the week after next as
well.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 824 PM EDT Sat Oct 31 2020

Strong disturbance set to cross the area tonight into
Sunday...dragging a deepening cold front across the area early
Sunday morning. Expect clouds to gradually lower and thicken,
with rain spreading across the taf locations overnight. Lake
processes quickly kick in behind the front, bringing MVFR to lower
end VFR cigs on Sunday. Lake effect showers, mostly of the snow
variety, will impact northern Michigan Sunday...although trends
support the most impactful snows falling between the taf
locations. Still, any heavier showers will be capable of
significantly reducing visibility and bringing some local
accumulations. Perhaps bigger story will be increasingly gusty
west and northwest winds on Sunday. Wind gusts nearing/exceeding
40 mph during the late morning and afternoon are likely, bringing
areas of blowing snow where accumulations occur. Low level wind
shear will occur tonight, this despite some gusty pre-frontal
southwest surface winds.


&&

.MARINE...
Issued at 1010 AM EDT Sat Oct 31 2020

Strong storm force winds expected Sunday. Winds are already
increasing this morning and will continue to increase into Sunday.
Southerly winds today ahead of an approaching cold front will
increase to gales this afternoon on all lakes. Once the cold front
moves through the area overnight, winds shift to the W/NW with
storm force winds expected. The wind relaxes Sunday night, but
will remain above advisory levels through Monday.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY from 7 AM to 7 PM EST Sunday for MIZ021-
     022-026>028-032-033-086.
     LAKESHORE FLOOD WARNING until 11 PM EST Sunday for MIZ016-020-
     021-025-026-031-098-099.
     WIND ADVISORY from 7 AM to 7 PM EST Sunday for MIZ016-020-021-
     025-026-031-099.
     LAKESHORE FLOOD WARNING until 1 AM EST Sunday for MIZ095.
     LAKESHORE FLOOD ADVISORY until 4 AM EST Sunday for MIZ096.
     LAKESHORE FLOOD WARNING from 1 PM to 11 PM EST Sunday for MIZ018.
LH...GALE WARNING until 1 AM EST Monday for LHZ347>349.
     GALE WARNING from 4 PM to 11 PM EST Sunday for LHZ346.
     GALE WARNING from 4 AM to 7 PM EST Sunday for LHZ345.
LM...STORM WARNING from 7 AM to 7 PM EST Sunday for LMZ323-342-
     344>346.
     GALE WARNING until 11 PM EST Sunday for LMZ341.
LS...GALE WARNING from 10 AM to 7 PM EST Sunday for LSZ322.
     STORM WARNING from 10 AM to 4 PM EST Sunday for LSZ321.
&&

$$

UPDATE...MSB
NEAR TERM...KF
SHORT TERM...AS
LONG TERM...AS
AVIATION...MSB
MARINE...KF