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410
FXUS63 KAPX 250140
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
940 PM EDT Sat Sep 24 2016

.UPDATE...
Issued at 939 PM EDT Sat Sep 24 2016

Skies are /almost/ clear across northern MI this evening. A band
of warm-advection related mid/high clouds, extending from nw
Ontario to ne Superior, is just grazing parts of eastern upper MI.
To our west, a patchy mid-cloud deck over WI is slowly edging
eastward, as easterly flow slowly gives way to sw flow in the
850-700mb layer. It`s progress will remain slow, but short-term
models support the leading edge of this cloud cover reaching
places west of TVC-CAD very late tonight. Otherwise, any cloud
cover in upper MI is and will remain thin.

Temps in the 50s in most places, with some upper 40s at PLN/DRM.
This is very reminiscent of last night, and will generally lower
min temps a bit in response.

&&

.SHORT TERM...(This evening and overnight)
Issued at 337 PM EDT Sat Sep 24 2016

High impact weather potential: None.

Pattern synopsis and forecast:

Mid level ridging and subsidence is moving into the western Great
Lakes this afternoon, with large sprawling high pressure in Ontario
influencing the entire Great Lakes region. Upper troughing and an
associated area of sfc low pressure was seen upstream in the
Dakotas, with a cold front extending south through the central
plains where showers and storms were firing. There was also a fairly
stationary frontal zone that extended from the sfc low through Iowa
and srn Il. On the north end of this front, cool and moist low level
air was resulting in fairly widespread stratus and gloomy weather.
Across nrn Michigan, we continued to see some decaying mid and upper
level cloud streaming in from central upper Michigan, as well as
daytime cumulus in eastern upper, and some Lake Huron generated
banded cumulus pushing into portions of NE lower (h8 temps of 5c).

Pretty quiet through Sunday. Mid level ridging slides right overhead
on Sunday with low level temperatures moderating/warming while also
swinging more in out of the SE as high pressure slides east of us.
The continued decay of the higher cloud, loss of daytime heating and
loss of instability over Lake Huron will lead to mostly clear skies
expected for tonight. Winds are also expected go fairly light/calm,
thus resulting in a pretty large diurnal temperature swing, only
thwarted to some degree by low level WAA. Lows tonight will span
the 40s, coolest in NE lower in those typical low lying areas,
especially the AuSable river valley.

The upstream low pressure system will gradually make it`s way
eastward, it`s cold front catching up to that stationary boundary,
and thus occluding. This occluded front doesn`t make it here until
Sunday night, but skies will be increasing in cloudiness as a
corridor of deeper moisture moisture ahead of the front arrives in
the afternoon, along with the initial dpva associated with the upper
trough that begins to close off. Rain will largely be saved for
Sunday night, but there are at least chances for far western
Chip/Mack counties and Beaver Island to see some rain late Sunday
afternoon. High temperatures Sunday in the upper 60s and lower 70s.
Another real nice weekend day.

.LONG TERM...(Sunday through Saturday)
Issued at 337 PM EDT Sat Sep 24 2016

...Unsettled cool weather for the first half of the week...

High Impact Weather Potential: Probably no headline producing
weather outside of the marine areas.  But will be wet starting
Sunday night with a substantial rain band moving through...then
showery/cool/blustery Monday and Tuesday.

Pattern Synopsis/Forecast: Slow moving upper level trough moving
through the Rocky Mountains this afternoon will make its way into
the midwest by Monday...and will be deepening as it slides across
the Great Lakes in the Tuesday/Wednesday time frame.  A blustery
cold front will cross Michigan Monday...bringing the coolest air
mass of meteorological fall thus far on the heels of gusty northwest
winds starting Monday afternoon.  Deep layer cyclonic flow will
linger across Michigan through Tuesday.

Primary Forecast Concerns: Pre-cold frontal rain band arriving Sunday
night is the initial forecast issue...fed by deep south/southwest
flow and a resultant strong feed of Gulf moisture pulling greater
than 1.50 inch precipitable water values into the upper Great Lakes.
Fortunately...precipitation band should be somewhat progressive
which will prevent excessive rainfall amounts.  Still some areas
likely to exceed an inch of rainfall Sunday night.

Heaviest rainfall will push east of Lower Michigan Monday morning...
as cooler air begins to spill across the forecast area in the wake
of the cold front passage.  Combination of cold air advection
increasing instability over the lakes...and moisture wrapping around
the deepening upper level circulation...will result in showers
developing Monday afternoon and will continue right on into Tuesday.
May even be some lake-induced rumbles of thunder during the time
frame as well.

Winds will also start to ramp up Monday behind the cold
front...gusting 20-30mph with gusts along the northwest Lower
shoreline around 35mph.  Temperatures not likely to go far Monday
with highs Tuesday mostly in the 50s.

JPB

Deep troughing will remain overhead going into mid-week, with lake
effect showers possible until mid level warming is able to shut down
lake processes. Currently, this looks to happen Thursday, as ridging
once again builds in from the west. The remainder of the period will
be characterized by surface high pressure and strong ridging, with
warm and sunny days through the weekend. Relatively cool, though
still slightly above normal, temperatures at the start of the period
will warm quickly, with weekend temperatures nearing 10 degrees
above normal.

ALM

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 715 PM EDT Sat Sep 24 2016

VFR.

High pressure ne of MI will move east. That will allow low
pressure to reach Lake Superior by late Sunday night. Clouds will
increase and thicken on Sunday ahead of this system. But no precip
is expected until Sunday night, and cigs will remain VFR.

Light winds tonight, a se to s wind up to 10kt on Sunday.


&&

.MARINE...
Issued at 337 PM EDT Sat Sep 24 2016

Light easterly winds will gradually turn more out of the SE tonight
and into Sunday, increasing fairly substantially Sunday afternoon
and Sunday night with the approach of a cold front. SE winds are
expected to reach advisory levels, while a swath of rain showers
works across the region. Much colder air settles into the region for
next week, with overlake instability leading to a long duration of
advisory level winds and choppy waters, as well as lake effect rain
showers. The set up will also be pretty decent for potential upper
low associated waterspouts.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY from 2 PM Sunday to 6 PM EDT Monday for
     LHZ345>349.

LM...SMALL CRAFT ADVISORY from 2 PM Sunday to 6 PM EDT Monday for
     LMZ323-341-342-344>346.

LS...SMALL CRAFT ADVISORY from 2 PM Sunday to 6 PM EDT Monday for
     LSZ322.

     SMALL CRAFT ADVISORY from 8 AM Sunday to 6 PM EDT Monday for
     LSZ321.

&&

$$

UPDATE...JZ
SHORT TERM...Dickson
LONG TERM...JPB/Mayhew
AVIATION...JZ
MARINE...Dickson