941
FXUS63 KAPX 060658
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
258 AM EDT Sat Sep 6 2025

.KEY MESSAGES...

- Another chilly, blustery, and showery day on tap.

- More shower chances tonight.

- Gradually drying out Sunday. Potential for frost Sunday
  night.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 258 AM EDT Sat Sep 6 2025

Current Overview / Pattern Synopsis:

Upper Great Lakes firmly entrenched withing the grips of a robust
area of longwave troughing that is settling into place. This will
remain the dominant weather feature through the short term period,
with various shortwave troughs pivoting around the parent surface
low (currently ~990mb over James Bay). These shortwave troughs will
continue to reinforce the chilly airmass across the region, and
drive additional shower chances through the day today and into
tonight... some with lake induced instability to help.

Forecast Details:

Current regime of showery activity confined to the vort max currently
draped across the Straits region and Tip of the Mitt amid prevailing
WSW flow, slowly dipping south toward the M-32 corridor as winds
begin turning more from the west. A shortwave trough looks to pass
through the region early this morning, providing another jolt of forcing
and turning prevailing flow more W to WNW. This may be accompanied
by a surge of more persistent lighter rain, particularly across northern
lower, through the morning hours before the core of this feature
departs eastward in the afternoon. This will leave the remainder of
the afternoon with less in the way of steadier rainfall, but more
of a passing shower regime. With the aforementioned wind shift,
anticipating the favored corridor of showery activity to trend more
south across northern lower through the day... favoring more of the
traditional lake effect belts along and south of M-32 through the
day in northern lower, and across Whitefish Point into the Soo across
the eastern Yoop. With cooler air bleeding in aloft, this will allow
for a pretty quick manifestation of diurnal instability across the
board in the afternoon. As such, most everyone will see a shot for
some additional shower activity through the afternoon, but with lesser
rainfall amounts / much more dry time outside the aforementioned
favored corridors.

As far as temperatures go, another chilly day on the docket as highs
probably struggle to get into the mid 50 across the interior terrain
of northern lower and the majority of eastern upper, with upper 50s
to near 60 expected elsewhere (perhaps lower 60s near Saginaw Bay).
Some peeks of sunshine between showers will give this quite the
dramatic fall feel across the Northwoods, sans the changing leaves.
W to WNW winds will start off relatively strong with some 30 to
35mph gusts not off the table in the morning, but tapering some
through the day.

Another wave is set to surge through the region later tonight, which
will drum up more showers across the region, with some help from the
lakes. There may be a lull in the activity as we lose diurnal
instability in the evening, but once this secondary wave shows up,
this will increase shower coverage, particularly across northwest
lower and the eastern Yoop. There is a hint of deeper instability
with this wave passage, so some of this activity, especially over
the open waters, may even be accompanied with a rumble of thunder or
two... and with a slackening pressure gradient... may actually be
more conducive for waterspout development on the Great Lakes later
tonight into Sunday. Lows tonight generally 38 to 48 (coolest
interiors). Cloud cover and continued flow should mitigate frost
potential tonight, more details to come in the ensuing forecast
cycle.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 258 AM EDT Sat Sep 6 2025

The last little blemishes of shortwave troughing will pivot through
the region early Sunday, bringing some more periodic shower chances
through the morning into the afternoon. Surface high pressure on the
backside of the system then works its way into the Great Lakes
region just in time Sunday night. With clearing skies and calming
winds, will need to watch closely for frost potential Sunday night,
which may wind up being the first more widespread frost event
(mainly across the interior). As that surface high begins to move
east into Lake Huron early next week, return flow and increasing
500mb heights will help to draw in far more seasonable, but still
somewhat below normal temperatures (avg highs 70 to 74 this time
of year) as highs peak 65 to 75 Monday and Tuesday, with continued
cooler nights in the 40s and 50s. Another wave looks to pass through
Tuesday into Wednesday, which will bring about another shot at some
showers. This will also knock back temperatures once again as we
progress through next week, with highs likely struggling into the
60s the remainder of the forecast period... but with drier conditions
to prevail.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 129 AM EDT Sat Sep 6 2025

Cool air and spotty lake effect rain showers will continue. Best
chance for rain will be CIU/PLN/TVC. Mostly VFR even with the
above, though brief MVFR conditions are possible (both
cigs/vsbys) in better showers. Breezy w to wnw winds continue,
but not as windy as Friday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through this evening for MIZ016-020-
     025-031-088-096-098-099.
     Beach Hazards Statement until 8 AM EDT this morning for MIZ017-
     018-021-024-026-030-036-042-095-097.
MARINE...Small Craft Advisory until 2 PM EDT this afternoon for LHZ345-
     346.
     Small Craft Advisory until 8 AM EDT this morning for
     LHZ347>349.
     Small Craft Advisory until 2 PM EDT this afternoon for LMZ323-
     341-342-344>346.
     Small Craft Advisory until 8 AM EDT this morning for LSZ322.
     Small Craft Advisory until 8 PM EDT this evening for LSZ321.

&&

$$

SHORT TERM...HAD
LONG TERM...HAD
AVIATION...JZ