Area Forecast Discussion
Issued by NWS Marquette, MI

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474
FXUS63 KMQT 130752
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
352 AM EDT Mon Oct 13 2025

.KEY MESSAGES...

- A round of showers presses west to east today. Rainfall
  accumulations are expected to remain light, generally less
  than 0.25".

- Gusty southerly winds 20-30 mph veer northwest behind a
  passing cold front, diminishing in speed throughout the day.

- Seasonable and dry weather follows into the midweek.

&&

.DISCUSSION...
Issued at 350 AM EDT Mon Oct 13 2025

Early morning RAP analysis and GOES satellite imagery reveal a ~110
kt 300mb jet extending from the Great Basin northeast across MN and
into western Ontario. Underneath the nose of this jet streak, a
~988mb sfc low is meandering east across central Manitoba. Closer to
home, the strong pressure gradient draped across the Upper Great
Lakes is continuing gusty S flow, which has kept low temps in the
50s area wide. Ascent ahead of and along the system`s occluded/cold
front is shoving a round of light rain across the west half of the
UP as of writing this discussion.

Through the reset of the day, the aforementioned frontal boundary
presses eastward through the CWA, providing a wave a light to
moderate showers as it does so. Guidance continues to highlight low
QPF amounts, with the NBM favoring a 25-50% chance for >0.25" mainly
confined to the Keweenaw. Elsewhere, expect lower amounts. Behind
the frontal passage, clearing skies and breezy NW winds will
prevail, providing wind gusts 20-25 mph to the Keweenaw and eastern
Lake Superior shoreline communities. Given increasing CAA and clear
skies, a chilly tonight is in store tonight where interior locations
could dip into the 30s where successful radiational cooling occurs
under a decoupling boundary layer.

Heading into the midweek, a deepening trough over the US west coast
forces downstream height rises and reintroduces sfc high pressure to
the Great Lakes. This keeps quiet and seasonable weather in the
forecast through at least Thursday. A few global models suggest an
increase in PoPs Wednesday as a weak ridge riding shortwave skirts
to our south, but opting to keep a dry forecast with antecedent dry
airmass and subsidence overhead. PoPs return in the forecast late
week and further into the weekend as western troughing continues
east across the Rockies, breaking down the Midwest ridge.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 205 AM EDT Mon Oct 13 2025

Radar shows a band of rain showers associated with a cold front
entering the far western UP as of 06z Mon, but observations
from around the area show VFR conditions with cigs still mainly
around FL100. Low level wind shear persists at the terminals
thanks to a LLJ bringing south winds of 45-50 kt at FL020. LLWS
will diminish at IWD and CMX by 08-09z and SAW by 10z as the
front progresses eastward across the area through Monday
morning, spreading showers into IWD and CMX through around 12z
and SAW through ~14z. Expect mainly VFR conditions to persist at
all sites, but could see a few brief bouts of MVFR through Mon
morning in passing showers. Winds shift westerly behind the
front by Monday afternoon, diminishing below 10 kt after ~22z
Mon.

&&

.MARINE...
Issued at 350 AM EDT Mon Oct 13 2025

Gusty southerly winds 25-30 kts with a few isolated gales to 35 kts
persist this morning as a tight pressure gradient is draped across
Lake Superior ahead of a cold frontal boundary that is set to press
west to east across the lake through this afternoon. As the front
presses east, gusty S winds diminish below 30 kts while veering to
the NW. For this reason, opting to let the ongoing Gale Warnings for
the N and central lake expire at 12z (8 AM EDT). Winds settle to
around 20 kts or less on Tuesday, save for some stray guts up to 25
kts over the southeastern waters, as high pressure builds in. Winds
settle below 15 kts across the lake Tuesday night, holding through
Thursday morning. High pressure quickly gives way on Thursday,
reintroducing 20-30 kt winds to the lake for next weekend.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning until 8 AM EDT this morning for LSZ244-245-
     264>266.

Lake Michigan...
None.

&&

$$

DISCUSSION...BW
AVIATION...CB
MARINE...BW