Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 120253

Area Forecast Discussion
National Weather Service Gaylord MI
953 PM EST Thu Jan 11 2018

Issued at 953 PM EST Thu Jan 11 2018

Cold front is basically bisecting our CWA late this evening...
with strong CAA kicking in immediately behind it. Temps have
fallen into the 30s across NW Lower Michigan...and into the 20s
across Eastern Upper Michigan. All indications are that precip
type is quickly changing from rain immediately to snow as CAA
takes over...with little to no indication of freezing rain
occurring. However...rapid freeze of wet surfaces from
afternoon/evening rainfall will cause slick spots on area
roadways...and have updated the SPS regarding this issue. CAA will
continue overnight...with precip quickly switching from rain to
snow from west to east. POPs will rapidly diminish...with little
in the way of lingering synoptic precip expected overnight. Some
weak/light lake effect will impact some of our shoreline areas
targeted by northerly flow...but again...any new snow accumulation
will be minor (i.e. under an inch). Temps will continue to plummet
overnight...with temps bottoming out in the single digits above
zero across Eastern Upper Michigan and in the teens across all of
Northern Lower Michigan.


.NEAR TERM...(Tonight through Friday)
Issued at 228 PM EST Thu Jan 11 2018

...Flash freeze?...

High Impact Weather Potential...Potential for any standing water
to quickly freeze up later this evening. This could make secondary
roads especially slippery.

Pattern Synopsis/Forecast...Low pressure and an associated arctic
cold front move across northern Michigan through early tonight.
Colder air moving over the Great Lakes will lead to a little lake
effect snow Friday.

Primary Forecast Concerns...Potential for a flash freeze tonight.
Small chance for a little freezing rain early tonight.

Through Tonight...The relative warmth of today will come quickly
to an end later this evening as an arctic cold front moves across
the region. In the meantime, rain showers will continue for the
remainder of the afternoon and early evening hours as weak low
pressure traverses the area. Not a whole lot of remaining moisture
behind the front (just a little). Model soundings indicate an
isothermal layer hugging 0 to +2C between about 725 and 875 mb
late this evening as the cold air starts to take hold at the
surface (-5C). This could lead to a brief period of mixed snow
and sleet (with a smaller chance for a little freezing rain).
Overall do not expect much snow/sleet accumulation...less than an
inch and little to no ice accumulation (from any freezing rain).
The bigger issue may be a flash freeze as standing water (rainfall
and melted snow) freezes from rapidly plummeting temperatures.
Will put out a special weather statement (sps) highlighting this
potential. Also of note is that any remaining ice covered
secondary roads may become treacherous as they freeze up solid.
Lows ranging from the upper single digits north to the upper teens

Friday...Plenty cold enough for northerly flow lake effect snow
showers as 850 mb temperatures drop to near -20C.
However...moisture is lacking (mean 850-700 mb rh only 20 to 30
percent). Therefore...only expect scattered mainly light snow
showers in the Grand Traverse Bay region and up near the Whitefish
Point area. Steady cold advection through the day leading to
nearly steady or slowly falling temperatures in the teens to lower
20s. Wind chill temperatures should range from 5 above to 10 below
zero so be prepared to bundle up.


.SHORT TERM...(Friday night through Sunday)
Issued at 228 PM EST Thu Jan 11 2018

High Impact Weather Potential...none.

Pattern Synopsis/Forecast...Large surface high moves in this
weekend. Northerly flow on the front side of the high will bring LES
Saturday. Flow becomes southwesterly Sunday as next system

Primary Forecast Concerns...Lake effect on Saturday should not
amount to much. NNW flow into decently dry air (850-700mb RH max
out at 50-60%, inversion height around 3 or 4kft) should direct
snow showers into the UP and Lake Michigan shoreline. NNW flow
should keep steadier snow showers more into central UP Saturday.
Southwesterly flow on Sunday will once again have a hard time
developing any significant snow in dry air and weak flow. Snow
showers will again be confined to the Lake Michigan shoreline
counties into the eastern UP.

.LONG TERM...(Sunday night through Thursday)
Issued at 228 PM EST Thu Jan 11 2018

Long range models are in agreement with a developing low pressure
system in the Plains pushing into the Great Lakes region Sunday
night, producing widespread snow for the forecast area through
Monday and into early Tuesday. As said system departs to the east,
colder air filtering in on northwest winds will develop some lake
effect snow Tuesday night through Wednesday afternoon. Drier air and
high pressure will then build into the region, providing
precipitation free weather Thursday with a bit of moderating
temperatures. Daytime highs will be in the teens through Wednesday
and then warm into the low to mid 20s Thursday. Lows will generally
be in the single digits.


.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 621 PM EST Thu Jan 11 2018

Unseasonably mild temps and remaining rain showers will rapidly
end this evening as strong CAA begins as an arctic cold front
sweeps thru the region. Rain will quickly change over to snow...
but any new snow accumulation will be minor (well under an inch).
Rapid drop in temp to well below freezing will lead to a quick
freeze of any wet surfaces. Rapid change in airmass and
strengthening of wind speeds as winds shift to the N/NW will end
our foggy conditions as well. Vsbys will improve to VFR...but
mainly MVFR cigs will hold on thru tonight into Friday. N/NW winds
will gust to 15 to 25 kts with gusts as high as 30 kts expected.


Issued at 228 PM EST Thu Jan 11 2018

Gusty southwest winds rapidly veer to northwest early this evening and
increase to gale force gusts tonight on portions of Lake Michigan
and Lake Huron behind a passing arctic cold front. Gale force
wind gusts continue through Friday morning with winds gradually
decreasing Friday night into Saturday.


LH...GALE WARNING from 1 AM to 1 PM EST Friday for LHZ347>349.
LM...GALE WARNING until 1 PM EST Friday for LMZ323-342-344>346.


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