219
FXUS63 KMQT 121156
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
756 AM EDT Sun Oct 12 2025

.KEY MESSAGES...

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

- Temperatures will average slightly warmer than normal through
  Monday before becoming more seasonable.

- There is a 50-70% chance for southerly wind gusts greater than
  30 mph this afternoon into Monday morning, particularly for
  favored downsloping locations of the western and central Lake
  Superior shorelines.

- A period of southerly gales around 35 kts is expected over
  central Lake Superior this afternoon and evening.

&&

.DISCUSSION...
Issued at 245 AM EDT Sun Oct 12 2025

Early morning RAP analysis and GOES satellite imagery reveal an
upper level ridge axis overhead the Upper Great Lakes with sfc high
pressure extending from Michigan NE into Quebec. Upstream, deep
troughing digs into the mountain west with a few embedded waves in
the N Plains ahead of the main trough. Surface cyclogenesis is
beginning to take shape across the N Rockies and far N Plains where
strong pressure falls are being observed. The increasing regional
pressure gradient has begun to uptick SSE winds as of writing this
discussion. Gusty southerly winds will be the main story today as
the parent trough swings NE across the N Plains, deepening a sfc low
near ~985 mb into Manitoba. Recent NBM and ensemble guidance
continue to highlight increasing winds this afternoon into Monday
morning, with the NBM favoring a 50-70% chance for gusts >30 mph in
the favored southerly downsloping areas of the western and central
UP, though would not shocked in the slightest to see similar gusts
across much of the east half. 00z HREF guidance continues to portray
much higher gust potential, which is often overdone is southerly WAA
regimes, however this may point toward a higher end potential rather
than an explicit wind gust forecast. Bufkit soundings across the CWA
continue to highlight mixing potential between 30-35 kts with the
occasional gust potential to 40 kts. Gusty S winds and midlevel WAA
will help bring daytime highs today and Monday into the 60s area
wide.

This wave and strong surface low lift northeast to Hudson Bay
tonight through Monday afternoon with high pressure building over
the Canadian Prairie in it`s wake. While better lift remains north
and west of the CWA, a preluding shortwave and occluded front sends
a round of showers from west to east across the UP late tonight
through Monday. Total rain accumulations range from a few hundreths
to 0.25", with a 25-50% chance for accumulations >0.25 mainly
confined to the west half by the time the front fully pushes east
Monday night.

High pressure moving in for the middle portion of next week leaves
dry and more seasonable weather likely through at least Wednesday
night. While cooler northwest becoming north flow aloft may result
in delta-Ts supportive of lake effect clouds during this time, model
soundings lack much moisture to yield precip. PoPs return on
Thursday, continuing through next weekend as this high pressure
weakens and departs to the east. At the same time, the mid level
ridge that had built up over the Midwest breaks down, shifting a
troughing pattern over the region for next weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 756 AM EDT Sun Oct 12 2025

Satellite imagery shows a patch of low stratus gradually eroding
over central parts of the UP as of 06z Sun, promoting VFR conditions
across most of Upper Michigan this morning. Latest observations show
SAW picking up a broken LIFR cig, but expect this to be localized
and short lived, with conditions quickly improving back to VFR by
~14z. Expect strengthening southerly winds today as the pressure
gradient tightens ahead of an approaching trough, with model
soundings depicting winds increasing to 40 kt at FL020 this morning.
Will leave LLWS out of TAFs initially as profiles remain largely
unidirectional with height. Will introduce LLWS later in the period
for IWD and CMX as winds continue to increase to around 50 kt at
FL020. A front approaches the western UP late in the period,
bringing a chance of rain showers to IWD 03-06z Mon, spreading to
CMX 06-08z and SAW ~12z Mon.

&&

.MARINE...
Issued at 245 AM EDT Sun Oct 12 2025

Impactful marine weather ramps UP this afternoon as a strong low
pressure lifts from the Plains northeastward into the Hudson Bay
through Monday. The resulting pressure gradient draped across the
Great Lakes will enable gusty southerly winds upwards of 30-35 kts,
mainly north and east of the Keweenaw where guidance suggests 50-70%
chance for Gales to 35 kts this evening into early Monday morning.
For this reason, continuing to hold the ongoing Gale Warnings for
the N and central Lake Superior zones 21z Sunday through 12z Monday.
Winds veer west behind a frontal boundary on Monday, gradually
settling to 15-25 kts by the end of the day. Winds settle to around
20 kts or less on Tuesday as high pressure builds in.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning from 5 PM this afternoon to 8 AM EDT Monday for
     LSZ244-245-264>266.

Lake Michigan...
None.

&&

$$

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