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000
FXUS63 KAPX 210206
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1006 PM EDT Tue Jun 20 2017

.UPDATE...
Issued at 1006 PM EDT Tue Jun 20 2017

A couple of showers linger in the Cheboygan area. Otherwise
precip has ended and clouds have substantially diminished
(especially in northern lower MI). Trend toward less clouds/
showers will be more emphatic than last night, as 500mb trof
pivots out of the region and heights rise overnight.

Less cloud cover and diminishing winds will allow for some in
spots, especially along the coasts and in places that saw decent
rainfall today.

&&

.NEAR TERM...(Tonight through Wednesday)
Issued at 243 PM EDT Tue Jun 20 2017

...Improving this evening...

High impact weather potential...some fog overnight along the
lakeshores.

Pattern synopsis/forecast...Shortwaves/trough axis exits MI to the
east this evening. Sfc high pressure and increased ridging Wednesday.

Primary forecast concerns/challenges... Showers will continue until
the trough axis moves through the region this evening. Showers will
wind down between 21-00z as shortwave/trough axis exit MI.
Otherwise, high pressure will move in overnight with increasing
ridging aloft setting up a more normal day to start the summer.

Clearing skies and light winds overnight will allow temperatures to
fall quickly. The very short night /in fact the shortest of the
year/ will keep temperatures from plummeting too much, but upstream
lows last night were in the 40s. The cool air moving in will also
help fog develop especially on the Lake Superior and Lake Michigan
nearshores and shorelines.

While the lower levels of the atmosphere do not warm much between
today and tomorrow, the increase in sunshine will raise temperatures

&&

.SHORT TERM...(Wednesday night through Friday)
Issued at 243 PM EDT Tue Jun 20 2017

...More showers and storms for the latter half of the week...

High Impact Weather Potential...Thunderstorm chances and a marginal
risk for severe on Thursday. Heavy rain also possible Thursday into
Friday as slow moving front becomes stretched across the region.

Pattern Synopsis/Forecast...Long wave troughing continues to
establish across central and eastern NOAM with long wave ridging
along the west coast building northward toward the Gulf of Alaska.
This cool-ish pattern (for the Great Lakes) looks to stick with us
through the next week and beyond (recent CPC outlook keeps below
average temperatures through early July). We do get a brief reprieve
midweek as subtle short wave ridging/slightly warmer air slides
through the region. But another piece of strong short wave energy
(in the Gulf of Alaska today) dumps into the upper Midwest/Great
Lakes region late in the week dragging cooler air back down into the
region heading into the weekend.

Primary Forecast Concerns...First forecast concern revolves around
heavy rain threat Thursday into Friday. Aforementioned strong short
wave (and attending surface low pressure) will be dipping into south-
central Canada and the northern lakes region Thursday into Friday
with a stretched out front becoming more of less west-east aligned
through lower Michigan. This will become the focus for one round of
showers/storms Wednesday night into thursday and renewed development
later Thursday into Friday before the front finally kicks through. A
returning moist airmass along/south of the front (PW values in
excess of 1.5 inches...possibly pushing 2)...west-east oriented
front and stronger upper flow running parallel to the front with
renewing rounds of precip along the front all suggest potential
heavy rainfall. But right now, that bigger threat may align across
central and southern lower Michigan where WPC Day3 excess rainfall
forecasts have focused. Will have to see how this unfolds but right
now...do not plan on highlighting a heavy rainfall threat up our
way.

Second concern...marginal severe risk Day3. As mentioned
above...there may be one round of showers/storms rolling through the
region Wednesday night into Thursday. Additional storms are probable
Thursday/Thursday night in the vicinity of the front. Stronger flow
aloft and modest instability suggest a threat of stronger
storms...but again primarily downstate where better instability will
be focused and as outlined in SPC DAY3 outlook with more a marginal
threat this far north. Again...will have to see how things evolve.

.LONG TERM...(Friday night through Tuesday)
Issued at 243 PM EDT Tue Jun 20 2017

High Impact Weather Potential...

The overall theme for the extended will be trending cooler and
breezy at times.  Just how cool remains to be seen...but I would be
remiss if I didn`t mention the fact that the Euro has the H8 zero
degree isotherm coming down and dipping it`s toes into the Straits
of Mackinac on Monday morning.  The GFS isn`t that cool...and being
that we`re greeting the summer solstice (nearly as we speak) I don`t
think the sun will allow anything too terrible to happen...outside
of some daytime highs around 70 and some overnight lows dipping into
the upper 40s.

Although our period will begin with weak surface high pressure on
Friday night and Saturday...an upper level trough will develop to
our north with a low setting up shop over Hudson bay for the
remainder of the period.  This will swing several rounds of energy
over the Great Lakes...with one such occurrence on Sunday and likely
our best chance at rainfall in the extended.  There are additional
chances on Monday and Tuesday for some instability driven showers,
but it`s kind of sketchy on how much moisture they`ll have to work
with...being this far off and all.  It`ll be something to pay close
attention to...as guidance would indicate we could be in for a
pretty unsettled weather pattern for the start of the new work week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 735 PM EDT Tue Jun 20 2017

Some fog potential tonight.

Low pressure over northern Quebec continues to extend troffing
back into the northern lakes. However, high pressure in MN will
gradually build into MI. This will erode diurnal showers and
associated cloud cover. For the most part, VFR conditions will
result. However, some ground fog could form in spots overnight,
mainly APN/PLN/MBL. For now, only MBL has a mention of MVFR/IFR
vsbys.

Lingering nw winds will become light this evening and remain so
into Wednesday (with developing lake breezes).


&&

.MARINE...
Issued at 243 PM EDT Tue Jun 20 2017

Winds diminishing overnight as high pressure moves in. Expect
light winds to continue through the day Wednesday.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...JZ
NEAR TERM...KJF
SHORT TERM...KAB
LONG TERM...KAB
AVIATION...JZ
MARINE...KJF