409
FXUS63 KMQT 261913
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
313 PM EDT Sat Sep 26 2026

.KEY MESSAGES...

- 40-60% chance of fog for the east half tonight.

- High temperatures remain slightly slightly above average in the
upper 60s to low 70s through early next week.

- A few rain showers may graze the western UP tonight into Sunday,
but chances for more widespread rainfall hold off until Tuesday into
Wednesday.

&&

.DISCUSSION...
Issued at 313 PM EDT Sat Sep 26 2026

Early afternoon GOES-East Day Cloud Phase RGB imagery shows some
isolated high cirrus, a couple patches of stubborn marine fog, and a
fair weather cu patch in Menominee County but otherwise clear
conditions across the region. The 500mb pattern resembles an omega
directly over the Upper Great Lakes with the peak of the ridge over
Lake Superior and deep troughs over the East Coast and over the High
Plains vertically stacked upon their respective surface features.
This pattern will gradually break down over the next few days,
beginning with the approach of the trough from the Plains tonight.

CAMs show a swath of scattered light rain showers approaching from
the west overnight. The absolute earliest that the HREF shows
showers arriving near Ironwood is 08Z, though as the showers push
east, they decrease in coverage until being almost entirely
dissipated by noon. Chances of any location getting measurable
rainfall totals are only around 50 percent, higher in the far west,
lower to the east. The rain is not going to be impactful either, as
the only areas with greater than 25% chances of a tenth of an inch
of rain are west of Marenisco/Lake Gogebic/M-64, and with that
entire area in D3 Extreme Drought, it would take more rain than that
to see meaningful relief. Elsewhere in the UP, light winds and clear
skies in the east half overnight will lead to radiation fog chances,
which per the HREF are around 40-60 percent.

Models are somewhat split on if light rain shower chances linger
Sunday night into Monday, though the NBM keeps it a dry solution. By
12Z Monday, the 500mb pattern shows a ridge axis that extends from
west TX to the UP bounded to the east by a closed low over New
Jersey and to the west by a closed low over central California and
Hurricane Polo, in addition to a shortwave over the Dakotas and
Canadian Prairie. These western troughs will help kick the ridge
quickly east, though not before quiet weather through at least
Monday night.

Hurricane Polo and the California closed low will merge over the
Four Corners by Wednesday morning as the Plains shortwave moves
through the region. The LREF shows 15-30% chances of precip entering
the west as soon as 18Z Tuesday with widespread 50-70% chances of
precip by 06Z Wednesday. A few rumbles of thunder can`t even be
ruled out as Euro ensemble mean MUCAPE 00Z Wednesday is up to 200
J/kg. This looks to be the best chance at widespread soaking rain in
some time as LREF chances of a quarter inch of rain per 24 hours is
over 40% for most of the UP at some point Tuesday through Thursday,
though there is enough spread in the details that a more precise
forecast is uncertain, especially late in the week as ensembles
struggle to agree on how to resolve the fate of the Four Corners low.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 212 PM EDT Sat Sep 26 2026

Continued high pressure pattern will result in mainly VFR conditions
with main impact being fog formation once again tonight. Included
IFR/LIFR visibility restrictions at both CMX and SAW early tomorrow
morning, but did only insert MVFR at IWD where cloud cover will
increase due to a shortwave along the ridge. In addition, will
carry VCSH mention at IWD tomorrow morning, which could briefly
drop cigs to the VFR/MVFR mark. Southerly winds will fluctuate
at times, but remain light in the 5 to 10 kt range.

&&

.MARINE...
Issued at 313 PM EDT Sat Sep 26 2026

Winds remain below 20 kt under high pressure until Tuesday, when an
approaching disturbance will drive wind gusts out of the south to
increase to near 25 kt, highest near Stannard Rock. Models are
uncertain around when winds swing from southerly to westerly and
northwesterly, but when they do, wind gusts will be 25% likely to
increase to gales (more likely to increase to 25-30 kt). Waves will
be highest for the nearshores of Lake Michigan, where the long-
duration and long-fetch southerlies increase the waves to near 3 ft.
With the onset of showers on Tuesday evening will be around a 15%
chance of thunderstorms.

&&

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

&&

$$

DISCUSSION...GS
AVIATION...TDUD
MARINE...GS