Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 300748

Area Forecast Discussion
National Weather Service Gaylord MI
348 AM EDT TUE AUG 30 2016

.SHORT TERM...(Today and tonight)
Issued at 347 AM EDT Tue Aug 30 2016

High impact weather potential: Scattered thunderstorms. Severe
weather not expected.

Pattern synopsis and forecast:

High pressure was over the eastern Great Lakes and much of western
Canada early this morning. In between, an area of low pressure and
it`s associated shortwave trough were in nrn Ontario. A cold front
extended south of the low, through western Lake Superior and srn MN.
A band of showers with embedded thunderstorms was laid out along and
ahead of this front, buried within a theta-e/instability max, and
forced/sustained by weak shortwave energy/vorticity in fairly weak
flow aloft and right entrance region jet dynamics. Nrn Michigan was
only seeing some convective debris clouds, primarily across eastern
upper, however there have been some new showers/storms trying to get
going around Whitefish Bay.

The cold front will cross eastern upper by early afternoon, then
sweep across nrn lower by late this evening. The air mass will be
fairly rich with low level moisture, and this air mass combined with
decent daytime heating and an analyzed vorticity maximum set for
late morning to afternoon, ought to make it pretty easy to develop
at least scattered showers and storms along and ahead of the cold
front. Fairly unimpressive lapse rates of 6c/km ought to negate some
of the expected 1000-1500 MLCAPE to keep updrafts from producing any
widespread severe weather, especially with relatively weakish flow
aloft. Should be more garden-variety type thunderstorms, but
isolated severe storms are possible. Chances for rain wane heading
through the overnight hours.

High temperatures today will range from the upper half of the 70s in
eastern upper to the middle 80s closer to Saginaw Bay. Lows tonight
in cool advection will generally be in the middle to upper 50s.

.LONG TERM...(Wednesday through Monday)
Issued at 347 AM EDT Tue Aug 30 2016

Models are in good agreement with surface high pressure beginning to
build into the region Wednesday...however an upper level trough and
some lingering moisture will be enough to keep partly to mostly
cloudy skies around through Wednesday night. The surface high
pressure continues to build as long as rebounding
heights...diminishing any remaining clouds Thursday. Light winds and
clearing skies may allow enough radiational cooling for some patchy
fog to develop over interior portions of northern Michigan Thursday
morning...but will be a better chance Friday morning as the surface
high centers over the Great Lakes region. This negative PNA setup
continues through the weekend with daytime temperatures only in the
upper 60s to low 70s through Friday and finally beginning to
moderate during the weekend...reaching into the upper 70s and low
80s as said surface high pressure begins to finally move to the east
of the CWA. Lows will be in the upper 40s to mid 50s through Sunday
morning and then only drop to the low 60s as the warmer
southwesterly flow develops. Return moisture arrives late Sunday
into early Monday ahead of a low pressure system near Hudson Bay,
returning chances of showers/thunder through the remainder of the
period as the forecast area sits under the eastern periphery of a
broad upper level trough, possibly the sign of a more cloudy and wet
change in the pattern to remain for several days to come thereafter.
The National Hurricane Center is also keeping an eye out on several
tropical disturbances. Depending on the exact strength and track of
any tropical system that develops, it could obviously change the
ongoing forecast.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1149 PM EDT Mon Aug 29 2016

Upstream cold front will slowly cross the area today and into
this evening. Just enough moisture/forcing to likely kick off a
few showers and thunderstorms, starting in the early morning hours for
KPLN, expanding across the rest of the sites during the day.
Confidence is extremely low in exact coverage, so will simply use
vicinity shower wording to cover for now. Otherwise, looking at
another morning for fog/br formation. Will continue to trend a
touch more pessimistically, introducing ifr conditions later
tonight at KMBL, and mvfr vis at both KAPN and KPLN.

Light/calm winds tonight increase just a touch in speed out of a
general west direction on today.


Issued at 347 AM EDT Tue Aug 30 2016

High pressure was over the eastern Great Lakes and much of western
Canada early this morning. In between, an area of low pressure was
in nrn Ontario, with a cold front extended to the south through
western Lake Superior and srn MN. This front will cross the Great
Lakes today and tonight bringing scattered showers and storms. SW
winds will veer westerly, then NW tonight behind the departing
front, with low end advisory level winds briefly possible. There is
a better chance for advisory level winds late Wednesday and
Wednesday night as the Western Canada high pressure shoves into the
central and nrn plains.


.APX Watches/Warnings/Advisories...


SHORT TERM...Dickson
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