489
FXUS63 KMQT 062356
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
756 PM EDT Sun Sep 6 2026

.KEY MESSAGES...

- Above-average temperatures and dry weather persist through Labor
Day, with high temperatures in the mid 70s to low 80s again on
Monday.

- A low pressure system tracking north of the area early next week
brings likely rain on Tuesday and breezy winds Tuesday and Wednesday.

- Frequent westerly wind gusts of 20 to 30 mph are expected on
Wednesday. There is a 25-50% chance for gusts up to 40 mph near Lake
Superior and 60-80% chance for gusts up to 45 mph in the Keweenaw.

- A Gale Watch for southerly winds up to 35 knots has been issued
for east-central Lake Superior on Tuesday. Westerly gales of
potentially 40+ knots are becoming increasingly likely across the
entire lake on Wednesday.

&&

.DISCUSSION...
Issued at 304 PM EDT Sun Sep 6 2026

Afternoon RAP analysis continues to show a stout upper level ridge
of high pressure encompassing the central CONUS and extending into
the Canadian Prairie, with surface high pressure extending over the
Upper Great Lakes from eastern Ontario and Quebec. This is resulting
in another pleasant day across the Upper Peninsula, with mostly
sunny skies and temperatures in the mid 70s to low 80s away from the
lakeshores as of mid afternoon. Increased high level cloud cover
emanating from an upstream disturbance over ND and MN tonight will
keep overnight temps a bit warmer than last night, with lows
generally in the mid 50s to low 60s across the area. This will also
help to limit fog development relative to last night, though the
southcentral and eastern UP still show a 15-25% chance for some
patchy fog through early Monday morning. High pressure remains in
control through Monday, resulting in another warm and dry, albeit
somewhat cloudier, day with 850 mb temps around 14-15C continuing to
support high temps in the upper 70s to low 80s across the area. Any
precipitation should hold off over the western UP until Monday night
with the approach of the next system.

The upper level pattern begins to shift Monday night into Tuesday as
the central CONUS ridge is flattened out by a deep trough lifting
out of the Pacific Northwest into the Canadian Prairie. This will
induce surface cyclogenesis in the lee of the northern Rockies on
Monday, with a strong low then tracking to the southern shores of
Hudson Bay by Wednesday morning and driving a strong cold front
across the UP late Tuesday into early Wednesday. Rain and embedded
thunderstorms will precede the front on Tuesday. Limited instability
on the order of 500 J/kg or less MUCAPE should help to preclude a
greater threat for strong/severe storms, but SPC does include the
western third of the UP in a marginal risk for Day 3 as bulk shear
increases above 40 kt. Expect most of the area to receive a wetting
rainfall from this event as latest NBM has a 65% or greater chance
to receive at least a quarter inch for a but the far southcentral UP
(closer to 50%) through Tuesday night. The western UP from the
Keweenaw to the Porcupines has a 40-60% chance to receive an inch or
more of rain on Tuesday, but those probabilities quickly drop off to
10-25% over the central and eastern UP. Rain should depart the
eastern UP behind the front by Wednesday morning.

This system will also make for breezy conditions from Tuesday into
Wednesday, with southerly winds increasing to 15-30 mph across a
wide swath of the area on Tuesday ahead of the front. The strongest
gusts on Tuesday will be in the areas favored by southerly downslope
flow, particularly from the Huron Mountains eastward along the Lake
Superior shoreline. Winds will shift westerly on Wednesday, aided by
cold air advection and pressure rises behind the front. Expect
widespread gusts of 20-30 mph through the day, with stronger gusts
to 40 mph possible near Lake Superior. Will need to consider an
eventual Wind Advisory for the Keweenaw as NBM now shows a 60-80%
chance for gusts of 45+ mph there. Meanwhile, there is also a 25-35%
probability for 45 mph gusts along the shoreline from east of
Marquette to Whitefish Point.

Expect calmer weather to return to the region by Thursday as high
pressure temporarily builds back over the UP behind the departing
system, with highs on Thursday closer to seasonal norms in the mid
60s to low 70s. However, the overall pattern remains unsettled as
another trough has the potential to bring additional rounds of
precipitation and breezy conditions from Friday into the weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 755 PM EDT Sun Sep 6 2026

VFR conditions over the TAF sites for the duration of the TAF period
due to high pressure ridging over the area. Expect calm to
nearly calm winds tonight with confidence too low at this point
to include any fog mention.

&&

.MARINE...
Issued at 304 PM EDT Sun Sep 6 2026

Lake Superior: High pressure influence keeps winds below 20 kts
through early Monday afternoon. A more prominent system lifting to
the north of Lake Superior Monday night through Wednesday brings a
prolonged period of widespread 20 to 30 kt winds. Have hoisted a
Gale Watch for east-central parts of the lake on Tuesday as
southerly winds increase ahead of the system. Most likely area to
see 35+ kt gusts on Tuesday will be over the open waters between
Marquette and Grand Marais, but also could see a few low end gales
westward into Keweenaw Bay. Also expect some gales around Isle
Royale with southerly flow on Tuesday, but do not see enough
coverage to justify a Gale Watch over the western lake at this time.
Would anticipate eventually needing small craft headlines for most
of the nearshore zones as the event draws closer. A potential high
end gale event (40-45 kt) will follow on Wednesday as winds shift
westerly behind the front aided by cold air advection and pressure
rises. Winds settle below 20 kts by Thursday afternoon. Another
system traveling north of Lake Superior brings stronger wind
potential into early next weekend, but significant model
discrepancies leave confidence low.

Northern Green Bay and northwestern Lake Michigan: Winds remain 15
kts or lower through Labor Day as high pressure remains overhead. A
more prominent system lifting north of the region early next week
increases winds to around 15 kts with gusts up to 20 to 30 kts
Tuesday afternoon through Wednesday. Anticipate an eventual need for
multiple periods of small craft headlines for southerly winds on
Tuesday and then west-southwest winds on Wednesday. Winds settle
below 20 kts by Thursday morning, holding below 20 kts into Friday.
Another system traveling north of Lake Superior brings stronger wind
potential into early next weekend, but significant model
discrepancies leave confidence low.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Watch from Tuesday morning through Tuesday evening for
     LSZ248>250-265-266.

Lake Michigan...
None.

&&

$$

DISCUSSION...CB
AVIATION...TDUD
MARINE...CB/77