515
FXUS63 KMQT 092332
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
732 PM EDT Thu Oct 9 2025

.KEY MESSAGES...

- Widespread light to moderate rain expected tonight and Friday.

- Gale force gusts to 35-40kts are becoming more likely Friday
  afternoon and evening over Superior (40-80% chance).

&&

.DISCUSSION...
Issued at 252 PM EDT Thu Oct 9 2025

Afternoon RAP analysis has the midlevel ridge axis shifting over the
Great Lakes this afternoon, with the surface high currently centered
over southern Ontario. Resulting southerly flow is bringing in
slightly warmer temperatures than in the past couple of days, with
most of the area sitting in the mid and upper 50s and expected to
peak near to just above 60F while skies remain sunny.


Meanwhile, a shortwave is currently dropping into Manitoba, with an
associated cold front extending southward into the Dakotas. The
compact shortwave continues moving into Ontario tonight with the
cold front tracking eastward towards the Great Lakes. Ahead of the
front, south to southwest winds will be on the increase; gusts up to
20-25mph will become more common overnight, but stronger gusts in
excess of 30mph will be possible in the southerly downsloping areas
nearer the Lake Superior. Winds over the water and across the
Keweenaw turn even stronger immediately ahead of and behind the
front with rapid height rises in its wake. Gale-force gusts will be
possible across the lake, while winds gust in excess of 30mph over
the Keweenaw. Winds quickly decrease Friday evening while shifting
over to the NW. Rain is also expected to press into Upper Michigan
from west to east tonight, becoming more widespread Friday morning
as a surface low develops along the cold front. Guidance continues
to favor development of the low around/just NW of Thunder Bay Friday
morning , slowly tracking southeast through the Great Lakes through
early Saturday. In terms of sensible weather, this means a dry slot
may support a break in rainfall early Friday for the west half
before a secondary push of rain wrapping around the low moves into
the forecast area in the afternoon and evening. Rain finally tapers
off Friday night. Most of the UP is looking to pick up a wetting
rainfall with widespread totals of a tenth to quarter inch by Friday
evening. However, NBM shows a low (25%) chance for higher rain
totals in excess of a half an inch, mainly across the northern half
of the UP. Perhaps this is due to some lake enhancement with the
second window of wraparound rain showers Friday afternoon/evening?
Will also note that while thunder is not looking very likely given
very limited buoyancy, will not rule out a rumble or two tonight
through Friday.

After rain wraps up Friday night, expect dry weather into the
weekend as a ridge  builds over the area once more. A slight warming
trend is noted between the two days thanks to the next system moving
closer to the region Sunday. Daytime highs Saturday look to peak
near 60F and then widespread mid 60s Sunday. Broad troughing begins
to establish itself across the Northern Rockies and the initial wave
lifting northeast from the base results in a surface low lifting
from the Dakotas into Manitoba Sunday. A warm front associated with
this system presses into the Upper Great Lakes Sunday night followed
by its cold front Monday. Rain looks to move into the region thanks
to these features Sunday evening then gradually taper through the
day Monday. This will also lead to another period of gusty winds
Sunday into Monday courtesy of a tight pressure gradient. Another
high looks to build across the region afterwards through the middle
of next week before the next low lifts out of the Central Plains.
Temperatures run cooler after Monday with highs in the 50s and lows
in the 30s and 40s.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 732 PM EDT Thu Oct 9 2025

VFR conditions early this evening give way to rain showers and
steadily worsening flying conditions as a cold front pushes through
from west to east tonight through Friday. While we could drop down
to MVFR vis during the showers, statistically-speaking the heaviest
rainfall is expected to miss the TAF sites (thus no vis below p6sm
in the TAFs); thinking the chances for MVFR or lower vis from the
showers across the terminals is around 20% or less. That being said,
cigs will drop to MVFR from west to east late tonight into Friday
morning across the TAF sites, potentially lowering into IFR cigs
later in the day Friday. Meanwhile, somewhat breezy southerly winds
ahead of the front become west and eventually northwesterly late
tonight through Friday across the terminals. Given the gusty winds
aloft during the overnight hours, some LLWS could be seen at IWD
tonight (CMX and SAW could see LLWS too, but the chances are lower).
Gusty northwest winds are expected behind the front by Friday
afternoon.

&&

.MARINE...
Issued at 252 PM EDT Thu Oct 9 2025

Southerly winds will be on the increase this evening into tonight
ahead of a cold front (currently over the Dakotas). By Friday
morning, a surface low will develop along the cold front, with winds
further increasing to around 30kts across much of the lake ahead of
and immediately behind the system. Gale potential still exists, with
the latest Euro ensembles coming in with the highest chances for
gales (around 50-80% chance), though this remains an outlier among
probabilistic guidance. Still, with strong winds aloft, and warm
lake temperatures suggesting a good potential for mixing, have
chosen to go slightly above guidance and add in some 35-40kt SW to
NW gales over central and eastern Lake Superior for the daytime
hours Friday. Gales quickly fall off Friday evening, and winds
continue to gradually decrease the rest of the night while slowly
veering to the northeast. Expecting winds below 20kts Saturday.
Increasing pressure gradient is expected late Saturday night into
Sunday as the next system organizes in the Northern Plains. An
upward tick has been observed in guidance, now suggesting that a low
end southeasterly/southerly gale looks good with this system late
Sunday/Monday. Winds become northwesterlies behind the system`s cold
front Monday night/Tuesday and slowly fall below 20kts by Tuesday
night.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning from 8 AM to 8 PM EDT Friday for LSZ242>244-263-
     264.

  Gale Warning from 11 AM to 8 PM EDT Friday for LSZ245>250-265-
     266.

Lake Michigan...
None.

&&

$$

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