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fxus63 kapx 151529 
afdapx

Area forecast discussion
National Weather Service Gaylord Michigan
1029 am EST sun Dec 15 2019

Update...
issued at 1014 am EST sun Dec 15 2019

Northwest flow lake effect is still ongoing...the highest reported
snowfall total so far is near Wellston...with 3 inches overnight.
Elsewhere is around a 1-2 inch average. Wouldn't doubt if someone
sees another 2 inches in Kalkaska County where the strongest band
has been set up for the past several hours. There are some signs
of the winds beginning to back, as forecast, and should start some
westerly flow lake effect and lighten the snow in intensity as
the sun does it's work and begins to break it up a bit.
Temperatures are in the mid teens to low 20s and won't budge much,
as highs are only forecast to be in the low to mid 20s.

&&

Near term...(today through tonight)
issued at 211 am EST sun Dec 15 2019

Impactful weather: minimal/none.

Pattern synopsis and forecast:

General upper level troughing was over the Great Lakes and into the
East Coast early this morning, with one shortwave and associated sfc
trough dropping into the western lakes and nrn Michigan. Minimal
forcing was associated with these features, and moisture in the
convective boundary layer was minimal. However, cyclonic low level
flow and continued cold advection, with 800 mb temps falling through the
negative teens, continued to result in light nuisance northwest flow lake
effect. Upstream, there was some shallow mid level ridging into
Manitoba and western Ontario, out ahead of the next shortwave now
dropping through Saskatchewan.

Heading through this morning, the western Great Lakes wave will work
across nrn Michigan, and inversion heights do Jump Up a touch, but
just to near 5kft. Would expect to see some sort of increase in
reflectivity on radar, however, any significant accumulation will
not occur, as we actually lose the cyclonic convergence of the low
level flow, and winds will not be locked in, rather they will be
backing to out of the west. The shallow mid level ridging and higher
sfc pressure starts moving in this afternoon, with subsequent drying
with lowering inversions, weaken and/or end any lake effect. Winds
backing more out of the west-southwest into the evening, and low level warm
advection decreasing the Overlake instability, will just add to the
more harsh conditions for sustaining any lake effect. Fcst soundings
show that the low levels actually will dry up almost completely by
late tonight. Should be no snow occurring by daybreak Monday.

Snowfall in the favored west-northwest/northwest flow regimes will be no more than 1-2
inches.

High temperatures will mostly be in the low to mid 20s. Lows tonight
will mainly be in the 5f-10f range in eastern upper, to the largely
the 10f-15f range in nrn lower.

&&

Short term...(monday through tuesday)
issued at 245 am EST sun Dec 15 2019

High impact weather: accumulating snowfall likely Tuesday afternoon.

Primary forecast concerns: snow accumulations Tuesday.

Not a whole lot of weather is expected Monday into Monday night with
nearly zonal flow aloft, weak surface ridging and fairly dry air in
place. Perhaps a few flurries here or there but that looks like
about it. A short wave moving by to the north Tuesday along with an
approaching Arctic cold front will bring a shot of synoptic
moisture. This is expected to ramp up lake effect snow showers by
Tuesday afternoon with some accumulation likely in west northwest
flow favored areas. Temperatures are expected to be a few degrees
below normal through this period.

Long term...(tuesday night through saturday)
issued at 245 am EST sun Dec 15 2019

High impact weather: accumulating lake effect snow showers
expected Tuesday night into Wednesday.

Lake effect snow showers will continue Tuesday night into Wednesday
as a quick shot of Arctic air (-22 c) dives into the region. This
will lead to brisk and very cold conditions along with additional
snow accumulations. Veering winds into the northwest will likely
shift the bands around. Possibly some warm advection driven snow
showers Wednesday night, otherwise not a lot looks like it'll be
going on across northern Michigan for a few days. Temperatures will
be 10 to 15 degrees or more below normal Wednesday then moderate to
closer to normal by the end of the week then possibly edge up to
slightly above normal next weekend (but a lack of flow may limit
this).

&&

Aviation...(for the 12z tafs through 12z Monday morning)
issued at 546 am EST sun Dec 15 2019

Cold advection in gusty northwest flow will continue to result in light
lake effect snow around pln/tvc/mbl this morning, with weakening
snow and winds into the afternoon, focused around pln, as winds turn
more out of the west with approaching higher pressure. Snows are
likely to end by tonight as conditions become more harsh for
sustaining any lake snows, and possibly even low clouds. MVFR cigs,
will gradually go to VFR with time. Snowfall will be a half inch or
less.



&&

Marine...
issued at 211 am EST sun Dec 15 2019

Cold advection has led to a tighter pressure gradient, and northwest winds
ramping into advisory speeds, which will continue today. There may
be a few gale force gusts along the NE Lower Lake Huron coast as
well. Winds back around more west-southwest later Sunday through Sunday night,
ahead of an approaching weak cold front. The gradient may stay tight
enough for some advisory winds to come back toward daybreak Monday
for Lake Michigan and Whitefish Bay. The gradient is then expected
to loosen back up for Monday night.



&&

Apx watches/warnings/advisories...
Michigan...none.
LH...Small Craft Advisory until 3 PM EST this afternoon for
lhz347>349.
Lm...Small Craft Advisory until 11 am EST this morning for lmz323-342-
344>346.
Ls...Small Craft Advisory until 11 am EST this morning for lsz321-322.
&&

$$

Update...tl
near term...smd

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