Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 202040
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
340 PM EST Sat Jan 20 2018

.NEAR TERM...(Tonight through Sunday)
Issued at 339 PM EST Sat Jan 20 2018

High impact weather potential: None.

Pattern synopsis and forecast:

Still a subtle hint of a weak frontal boundary draped across nrn
Michigan, with the other more defined boundary which has sunk a bit
further south now, from south central Canada through Lake Superior
and back up into low pressure in Quebec. Flow in the mid levels
remains rather convergent with a srn branch coming out of the
Rockies and the nrn branch coming out central Canada, converging
into the north central plains and the nrn Great Lakes. There was a
weak shortwave in Manitoba/ND that continues to press ESE along the
more defined frontal zone to our north. Latest satellite showing the
the corridor of relatively deeper moisture is behind this front, and
a shade further north than earlier anticipated. To the south, latest
satellite showing stratus across the mid Mississippi valley is
trying to mix out, but does have a northward movement as winds in
that region have turned south, behind another frontal zone attached
to developing low pressure in Colorado.

The shortwave still expected to dampen with time, as it passes this
evening, further north of chippewa county with minimal to nil
forcing. Was only a very very small chance for chippewa to see a
little chance for light precipitation, but that now looks like it`s
also basically zero chance.  The only thing going for this scenario,
is the potential for a touch of FGEN developing up there as the mid
level flow constricts even further. Otherwise, it`s still just some
higher level cloud pressing across the region tonight. The stratus
in the mid Mississippi valley will be creeping northward through
tonight as our winds turn light out of the south, but likely will
not make it up here until through the day Monday. Fcst soundings not
suggesting we will be mixing out, but rather expanding into much of
the region. Not so sure about that. We will remain in basically a
forcing-less zone through Sunday with no precipitation expected. In
the meantime, the low pressure in Colorado deepens into the central
plains. Deeper Gulf moisture feeds into this system through the day,
and expect a band of showers and storms to develop and work into the
lower Mississippi valley, with snows developing on the backside of
the low pressure, within the deformation and cold advection. No
precipitation anticipated. This storm system advertised for the past
few days will be getting it`s act going. More on that below.


&&

.SHORT TERM...(Sunday night through Tuesday)
Issued at 339 PM EST Sat Jan 20 2018

...Messy wintry mix will impact travel...

High Impact Weather Potential...Significant snow and ice
accumulations possible in some areas, which will make for difficult,
if not hazardous, travel.

Pattern Synopsis/Forecast...A storm system in the Southern Plains,
just in the lee of the Rockies moves to the mid-Missouri River
Valley, by 12z/Monday. As it moves east, the warm front that
associated with the sfc low stretches east through lower Michigan.
Precipitation will slowly move north through Sunday night into
Monday along the warm front. As the precipitation begins to fall
especially in N Lower, there will be a wintry mix, or possibly just
freezing drizzle. GFS shows that there will be a few dry layers in
the sounding initially, so some of this looks to possibly start as
drizzle or freezing drizzle, before moistening up enough to have ice
crystals aloft, so that E Upper will remain with snow through the
night into Monday. A dry slot evident on the 700-500 mb layer
moisture begins to move into the region by the afternoon, which will
change some of the snow/rain to drizzle/freezing drizzle. As the low
moves into the state, the moisture returns during Monday evening and
rain/snow/Freezing rain will change over to all snow overnight. Then
as the low moves out of the forecast area, Tuesday, 850 mb cold air
moves into the region and the LES processes begin to take over as
the 850 mb temperatures fall to around -16C by 00z/Wed on the GFS,
but -8c on the ECMWF.

Primary Forecast concerns...Models, on this run, seem to have come
up with a consensus track with sfc low moving through N lower and
the 500 mb low through S Lower. The Moisture is roughly similar with
the dry slot as it moves through as well. So will watch and see if
this comes about. The next probably is the Chance for Freezing
rain/drizzle. This is looking like an issue along the M-55 corridor
sunday night into as portions of the SE counties in the forecast
area could have a tenth or so of ice. WPC graphics as a first look
has around 0.25" in N lower for the 24 hours Sunday night into
Monday, with a probability of 50% for equal to or greater than
0.25".

Snow in the UP looks to be moderate amounts during Monday and
lighter amounts Monday night into Tuesday.

Right now, since the tracks have been all over the place the last
few days, we will hold off issuing a watch at this point. However,
if this track remains for another run, then watch will be warranted.

&&

.LONG TERM...(Tuesday night through Saturday)
Issued at 339 PM EST Sat Jan 20 2018

Lingering lake effect snow showers and wrap around moisture from a
departing low pressure system will begin to diminish and/or become
very light as deeper moisture exits along with said system. High
pressure and much drier air will then build into the Great Lakes
region providing precipitation free weather Wednesday through much
of Friday. Precipitation chances return late Friday through Saturday
as a clipper system skirts the northern Great Lakes. Highs will only
be in the teens to mid 20s Wednesday and moderate into the upper 30s
to low 40s by Friday. Lows will be in the single digits Wednesday
and Thursday morning and drop only into the upper 20s to low 30s by
Saturday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1205 PM EST Sat Jan 20 2018

Thinner higher level clouds out there thus far, but mid and upper
clouds will increase again later today through tonight. Through
Sunday, IFR CIGS expected to develop from south to north through
the NW lower airports during the day as winds turn light
southerly, drawing up current stratus over Illinois. Still VFR
CIGS expected for now at APN. This light winds tonight and into
Sunday will also likely result in the development of at least some
light fog across nrn Michigan. Still no precipitation expected
this TAF period, and likely not until late Sunday night into
Monday morning.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
&&

$$

NEAR TERM...SMD
SHORT TERM...JL
LONG TERM...TL
AVIATION...SMD



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