FXUS63 KMQT 162129

Area Forecast Discussion
National Weather Service Marquette MI
429 PM EST Sun Dec 16 2018

.DISCUSSION...(This evening through Sunday)
Issued at 354 PM EST SUN DEC 16 2018

Weak trough axis grazing past the region tonight could be enough
of a trigger to initiate some light snow showers across the
eastern portions of the U.P., in addition to perhaps some flurries
elsewhere. Dry air that has been in place, coupled with not much
additional atmospheric moisture advecting in with this shortwave,
will be the limiting factor for precip and accumulations. With
Lake Superior's help, the eastern third could pick up some very
minor snow accumulations, and by very minor, on the order of up to
an inch. By tomorrow night, surface high pressure/ridging aloft
will have moved into the northern Great Lakes region, cutting off
precip chances area-wide through early Wednesday.

The next synoptically-driven precip chances look to arrive later
in the week as an amplifying trough approaches and crosses the
region. Models are in general agreement that as this trough
amplifies, cyclogenesis is kicked off in its southern tip. From
Thursday onward, the low looks to deepen, tracking up into the
Mid-Atlantic states by week's end, continuing its path into New
England by early next weekend. By the end of next weekend, model
solutions diverge as is typical that far out. What this all
equates to locally is that the initial approach of said trough
will help facilitate precip chances by late Wednesday into
Thursday, with the aforementioned deepening low grazing past
Friday into Saturday potentially serving as another focus for
precip chances. By Saturday though, although the low will be
brushing past, precip chances could be more locally-driven as
possible lake-effect activity prevails. Will be able to better
refine this forecast as that time period approaches.

Highs today have exceeded what was expected, but CAA is knocking
on Upper Michigan's door. The previously advertised frontal
passage tonight will be felt as temps dip into the teens and lower
20s across the west half, and mid to upper 20s in the east half.
Certainly don't look for as warm of temps tomorrow, topping out
below freezing area-wide. This brief cooldown won't last long as
southerly flow returns by Tuesday, advecting much warmer air back
in. Highs above freezing look to be a safe bet through Thursday,
with N-NW flow returning at the end of the week and temps
returning closer toward normal for mid-December. Look for lows to
respond accordingly.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1248 PM EST SUN DEC 16 2018

Winds veer from W to NW this afternoon and evening as a weak cold
front moves through from west to east. Main story will be blustery
NW winds behind this front at all three TAF sites, but especially at
CMX where winds off Lake Superior will likely gust into the mid-
upper 30s knots for much of the night. Gusts are expected to
gradually die down from west to east Monday morning. A few very
light/widely scattered lake-effect snow showers are also possible at
CMX overnight but these should be very low impact. Occasional broken
MVFR cigs have been observed behind the front as well, so have
reflected that in all three TAFs.

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 354 PM EST SUN DEC 16 2018

Northwest gales will continue well into tonight, eventually
tapering off by around midday tomorrow. Sustained winds of 20+
knots will remain possible across the eastern half of Lake
Superior through tomorrow evening, dropping to less than 15 knots
everywhere overnight. However, this will be short-lived as
southerly flow takes over Tuesday, and 15-25 knot sustained winds
take back over, with just shy of gale-force gusts possible. By
Wednesday, look for sustained winds to retreat back down to 10-15
knots through early Thursday, looking to pick back up late
Thursday through week's end as N-NW winds return.


Upper Michigan...
Lake Superior...
Gale Warning until 9 AM EST Monday for LSZ248>251-265>267.

Gale Warning until 6 AM EST Monday for LSZ244-264.

Gale Warning until 1 AM EST /midnight CST/ Monday for LSZ241>243-

Lake Michigan...


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