942
FXUS63 KMQT 301101
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
701 AM EDT Sun Aug 30 2026

.KEY MESSAGES...

- Patchy dense fog is possible (50-75% chance) across the
  interior UP early this morning and again tonight.

- Additional showers and storms are possible today and early
  this week.

- Above normal temperatures and higher humidity is expected this
  week into early September.

&&

.DISCUSSION...
Issued at 248 AM EDT Sun Aug 30 2026

Rain showers have mostly dwindled away and have become relegated to
the southern half of the U.P. early this morning as the first
shortwave has now passed through the area. While not much
precipitation has been seen over the past 24 hours, enough has
fallen to potentially produce areas of fog across the land before
dawn this morning. However, a `wrench` in the fog prediction is the
upper-level cloud cover overhead; this cloud cover will actually
limit fog development as it will weaken the inversion just above the
sfc. Regardless, some spots could get down to quarter mile or less
visibilities. Should this occur, then an SPS or Dense Fog Advisory
could be forthcoming. As the sun rises, expect the fog to slowly
dwindle away, with the U.P. becoming fog-free by the mid to late
morning hours.

A second shortwave looks to move through the Upper Midwest today,
with maybe some showers and weak thunderstorms moving through the
area today. However, with the shortwave moving through south of the
area (i.e. Wisconsin and central Lake MI), rain chances seem fairly
limited, ranging from around 10% in the Keweenaw and in Luce County
all the way up to 30/35% in the interior west and south central.
Behind this shortwave, additional fog could form across the region
tonight.

Things become more interesting during the overnight hours as a warm
front 24-hours ago looking to come during the day on Monday is now
slated to arrive earlier, potentially bringing heavy rain showers
and thunderstorms back across the U.P. during the overnight hours.
Because the warm front now looks to be coming in during the
overnight hours, expect the severe weather threat to now be very low
if not next to zero as instability will be limited to above the sfc
inversion and the mid-levels. That being said, won`t completely rule
out a stronger thunderstorm or two where some sub-severe/non-
damaging hail and gusty winds could be seen. In addition, some spots
may actually see a wetting to even soaking rainfall from this round
of convection, as the latest HREF shows a 30 to 85% chance for at
least a quarter inch of rainfall with the passage of the warm front
tonight through Monday; there is even up to a 60% chance for some
portions of the interior west to see over an inch of rain (including
Ironwood). The rainfall would also bring an end to the fog threat
overnight, although fog could reform before dawn Monday morning once
the rain showers and storms cease across any particular area. That
being said, as the warm front continues NE late tonight through
Monday, CAMs show the line of convection along the warm front
breaking up and weakening with time during the early morning hours
on Monday. While a second round of convection may occur via a
secondary shortwave moving through behind the warm front Monday
afternoon, expect this round of precipitation to be rather quick, if
it even moves through at all. Thus, not as much rainfall is expected
over the more NE areas of the U.P. late tonight through Monday, and
flash flooding is not expected given the very dry ground.

Expect rain chances to in general decrease for the remainder of the
forecast period as high pressure ridging builds back over the
central CONUS and into the Great Lakes region. That being said, the
latest runs of the medium range guidance do suggest that a shortwave
rotating on the southern end of the ridging could move through the
Upper Great Lakes this Wednesday. If the track of the shortwave is
close enough to the U.P., some additional (much-needed) showers and
thunderstorms could be seen across the area. Otherwise, expect
mainly dry weather, although the above normal temperatures and humid
conditions seen today look to continue into early September as Gulf
air continues to be funneled into the region.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 701 AM EDT Sun Aug 30 2026

Expect fairly poor flying conditions over the next 24 hours compared
to normal as low-level cloud cover stubbornly holds on today, before
an incoming warm front brings additional SHRA and TSRA tonight
(mainly over IWD and SAW). Ahead of and even behind this warm front,
expect FG to develop over the terminals, dropping all of the TAF
sites to LIFR or lower near the end of the period; the SHRA and TSRA
may bring some vis relief from the FG as they move through, but
expect lower cigs down to LIFR regardless; don`t be surprised to see
FG return behind the rainfall tonight. While we will eventually see
an improvement to MVFR by this afternoon over SAW and CMX and
potentially even VFR at IWD, expect the improvement to those
conditions to take several hours (between now and this afternoon).
And, once the sun sets, expect the conditions to deteriorate rapidly
once more. Expect the winds to build from the E/SE with time today
as the warm front approaches. The sustained winds lighten up a
little but continue as they slowly veer throughout the overnight
hours.

&&

.MARINE...
Issued at 248 AM EDT Sun Aug 30 2026

Lake Superior: Light winds of 20 kts or less increase to NE winds of
20 to 30 kts over the western lake by this afternoon as a warm front
approaches. As the showers and storms associated with the front
start to move in tonight from the SW, expect the winds to dwindle
over the western lake while increasing from the SE to 20 to 25 kts
over the eastern half of the lake on Monday. Some stronger storms
with gusty winds up to 34 kts and marginally severe hail up to dime
sized could be seen over the far west this evening, but expect the
shower and storm coverage as well as the marginal marine severe
threat to diminish with time tonight into Monday. Expect light winds
of 20 kts or less to return to Lake Superior Monday night. However,
SW winds of 20 to 25 kts could return between Isle Royale and the
Keweenaw on Tuesday before becoming 20 kts or less again Tuesday
evening. The light winds remain until potentially late on Thursday
when NE winds of 20 to 25 kts possibly return to the western arm.

Northern Green Bay and northwestern Lake Michigan: Light winds of 15
kts or less this morning look to continue until Monday. Meanwhile,
some showers and storms could be seen today through tonight, with
some potentially marginally marine severe weather possible tonight
(gusty winds up to 34 kts and hail up to dime sized). We could see
some S`rly winds of 15 to 20 kts over the area on Monday before
winds return to 15 kts or less Monday evening. The light winds
continue through the rest of the week, although some more showers
and storms could return on Wednesday.

&&

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

&&

$$

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