418
FXUS63 KMQT 281726
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
126 PM EDT Mon Sep 28 2026

.KEY MESSAGES...

- Highs in the upper 60s to mid-70s continue today and Tuesday.

- A few shortwave lows tracking through the Central CONUS could
  bring rain chances back into the U.P. late Tuesday into
  Thursday, followed by cooler and more seasonable temperatures.

- Marginal (~35 knot) west-northwest gales are possible (30-50%
  chance) along the southern Lake Superior shoreline from the
  Keweenaw to Whitefish Point on Thursday.

&&

.DISCUSSION...
Issued at 125 PM EDT Mon Sep 28 2026

As high pressure ridging leaves the Upper Great Lakes this afternoon
through tonight, expect mostly sunny skies across the area to allow
highs to reach into the mid-70s across much of the area once again,
allowing for pleasant early-Fall weather to complement the gorgeous
Fall colors across the Yoop. Heading into the overnight hours,
expect the mostly clear skies to continue, allowing the temperatures
to tank down to the dewpoint once again and creating areas of fog;
could see the need for a Dense Fog Advisory for portions of the
interior U.P. tonight into Tuesday morning given that visibilities
could become a quarter mile or less, but confidence on the timing of
the fog and where it will be dense (quarter mile or less vis) at is
too low at this point in time to issue Special Weather Statements or
Dense Fog Advisories. Nevertheless, the greatest chances for dense
fog do look to be in the east half tonight as some upper-level cloud
cover begins to move into the western U.P. by the early morning
hours; expect lows around 50 in the west to the 40s and potentially
even mid-30s over the interior east tonight.

Attention then turns to troughing over the central CONUS on Tuesday
that develops split flow, with one low moving through Canada towards
Hudson Bay while another forms in the Southern Plains before lifting
and dissipating northeastward towards the Mid-Atlantic/New England
through the mid to late-week period. With this in mind, a preceding
shortwave low lifts from the Northern Plains towards Hudson Bay on
Tuesday, bringing upper-level cloud cover across the area.
Nevertheless, expect another pleasantly warm Fall day on Tuesday,
with the U.P. perhaps being set up with some light rain showers late
Tuesday into Wednesday as the shortwave passes along the periphery
of our area. While the 850mb LLJ increases up to 35 to 45 kts aloft
Tuesday afternoon and evening with the passage of the shortwave low,
no severe weather or even breezy conditions are expected as there
will be very little to no instability to work with aloft and capping
is expected just above the sfc due to subtle WAA creating a stable
atmospheric profile in the lower levels. While the low that develops
over the Southern Plains and lifts towards the Mid-Atlantic/New
England could bring additional light rain showers to the area
Wednesday into Thursday, more medium range guidance does suggest a
more southerly track to the precipitation chances, with now only the
south central and east perhaps seeing synoptic rainfall, if even
that. That being said, once the cold sector moves through, expect
winds to pick up from the west to northwest across the area late
Wednesday night and Thursday; while the temperature advection and
height rises do weaken with time on Thursday, we could see wind
gusts of 30 to potentially even 40 mph along the Lake Superior
shoreline on Thursday. In addition, the delta-Ts and winds over Lake
Superior may be enough to kick-off some quick-hitting lake/upslope-
induced light rain/drizzle showers over the northwest wind belts
before ending by Thursday evening. Overall, rain totals continue to
decrease with this event, with expected amounts now around a tenth
to quarter inch for most of the west and north central. While the
south central and east could see around half an inch of rainfall or
more, only the area near Menominee now looks to receive an inch or
more of rainfall, with the NBM now only showing up to a 50% chance
of that happening.

Moving into the rest of the week into this upcoming weekend, expect
more normal Fall temperatures as highs are projected to only rise up
into the lower 60s during the afternoon hours from Thursday onward.
With high pressure redeveloping over the Northern Plains for the
latter portion of the week behind the troughing and potential
rainfall, expect fairly pleasant Fall weather to continue until rain
chances potentially return with a Clipper low this weekend. Given
the fairly clear skies expected with the ridging moving through late
this week, we may see some widespread frost develop over the
interior areas Thursday and Friday nights; keep an eye on the
forecast to see the latest updates.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 125 PM EDT Mon Sep 28 2026

VFR conditions with light winds are expected to continue through
this evening. High-based cloud cover is expected to move into the
area tonight, beginning with KIWD and progressing eastward
overnight. Winds overnight will be light, shifting to southerly, and
will pick up speed again around sunrise. Fog is possible for KCMX and
KSAW after 03z, however there is uncertainty surrounding the extent
of the densest fog. KCMX has a 25% chance of seeing MVFR conditions.
KSAW has a better chance of reaching MVFR conditions (around 50%),
with a lower chance (around 15%) of seeing IFR conditions. Given the
lower chances for visibility impacts, KCMX remains at P6SM in the
TAF, while KSAW visibilities have been dropped to 5SM with BR from
03z to 13z Tuesday.

&&

.MARINE...
Issued at 125 PM EDT Mon Sep 28 2026

Lake Superior: Light winds of 20 kts or less continue the rest of
this afternoon through tonight as high pressure ridging retreats to
the east and troughing builds in from the Northern Plains. With a
shortwave skirting our area to the northwest Tuesday and Tuesday
night, expect southerly winds to increase to 20 to 25 kts over the
lake, with gusts up to 30 kts being possible over the eastern open
lake late in the day as a LLJ moves into the area. The winds do
generally slacken to 20 kts or less by Wednesday behind the
shortwave, but the eastern open lake may hang on to southerly 20 to
25 kt winds until Wednesday evening. As CAA moves into the area
early Thursday through the rest of the day, expect winds to pickup
from the west-northwest to 20 to 30 kts across the lake, with gales
up to 35 kts possible along the southern shoreline from the Keweenaw
to Whitefish Point (the current NBM has gales at ~35 kts or higher
at 30 to 50% along the aforementioned area for Thursday). As ridging
builds back in late this week, expect the winds to die down to 20
kts or less again by Thursday night/Friday morning and to remain
that way through Saturday.

Northern Green Bay and northwestern Lake Michigan: Light winds of 15
kts or less hold the rest of today through tonight as high pressure
ridging retreats to the east while troughing approaches from the
west. Expect winds to pick up from the south and southwest to 15 to
20 kts by Tuesday as a shortwave passes by the area from the
Northern Plains to Hudson Bay. The winds may increase to 20 to 30
kts by early Wednesday as a low over the Southern Plains dissipates
and heads towards the Mid-Atlantic/New England. However, once it
passes expect the winds to have a quick reprieve down to 15 kts or
less Wednesday night/Thursday morning before picking back up to 15
to 20 kts from the northwest on Thursday via CAA. Expect the winds
to slacken to 15 kts or less again by Thursday night and to remain
light the rest of this week as ridging returns to the area.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

DISCUSSION...TAP
AVIATION...LH
MARINE...TAP