180
FXUS63 KDLH 061138
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
638 AM CDT Mon Oct 6 2025

.KEY MESSAGES...

- Cool weather for a few days. Patchy frost is possible tonight,
  mainly for the usual inland cold spots.

- A widespread freeze is likely Tuesday night into Wednesday
  morning.

- Gradually warming temperatures later this week into the
  weekend. Some rain is possible Thursday and Sunday.

&&

.DISCUSSION...
Issued at 220 AM CDT Mon Oct 6 2025

Cold air advection is in full swing following cold frontal passage
earlier in the evening. Other than a stray light shower or two this
morning along the Canadian border, we can expect low clouds to
gradually erode today as drier air moves in with high pressure. Some
mid to high level clouds may pass through with some weak lift aloft.
Otherwise, the main story will be the cooler temperatures today with
highs only in the 50s to 60s. West winds are expected to gust to 15-
20 mph...a little breezy, but light compared to Sunday.

Frost and freezing temperatures will be possible the next
couple nights. Tonight, we will still have a bit of a pressure
gradient and thus some light winds. A trough aloft may also
result in some clouds and perhaps even a few light rain/snow
showers up around the International Border. With all that, frost
potential is looking like it will be patchy. Some of the usual
cold spots could see a bit of frost. The upper level trough will
move east on Tuesday with surface high pressure building in
overnight. A reinforcing shot of cooler air from the northwest
is expected Tuesday, and it will settle in with winds becoming
light to calm Tuesday night. Tuesday night into Wednesday
morning will be the main show for frost, and at this point we`re
looking at a >50% chance at temperatures falling below freezing
pretty much everywhere except within a few miles of Lake
Superior. This could very well be a season-ending freeze for
many to most places.

Immediately following the cold temperatures Wednesday morning, upper
level ridging will move in aloft with southerly flow and warm air
advection developing on the west side of departing surface high
pressure. A nice recovery of high temperatures into the 60s are
expected away from Lake Superior, where onshore flow will keep
temperatures cooler.

The warm air advection regime continues into Thursday, and a weak
shortwave aloft and a weak cool front may be enough to kick off some
light rain showers (~25% chance). Rainfall amounts should be very
light (up to a tenth of an inch or two on the high end). After a
quick surface high passes through, warm air advection continues into
Friday and Saturday. Dry weather is expected and temperatures are
expected to moderate to the upper 60s to low 70s for highs going
into the weekend.

It`s looking likely that a broad upper level trough will develop
over the west this weekend with a cold front potentially making its
way through our region around Sunday. We could see some rain with
this (~50% chance) followed by some cooler weather into next
week.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 638 AM CDT Mon Oct 6 2025

MVFR stratus at INL may be slow to lift according to the latest
short-range models. Several hours of low ceilings can be
expected there this morning. Elsewhere, VFR conditions are
prevalent. There is a low (~10% chance) for fog at BRD the next
hour or two with nearby observations reporting it, but since it
hasn`t happened already, it`s more likely that it won`t at all.
Other than some mid to higher level clouds today, once low
clouds scatter out later this morning, VFR conditions are
expected the remainder of the period with dry air moving in.
Winds will be generally westerly, becoming southwesterly later
this afternoon and tonight. Some breezy conditions with gusts up
to 15-20 kt are expected, especially at INL. Tonight, a weak
short wave trough could bring a stray light shower to INL, but
otherwise uneventful weather is expected tonight.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 220 AM CDT Mon Oct 6 2025

Winds are expected to continue to decrease through the early
morning hours. Therefore, headlines will be allowed to expire.
It is possible that there could be isolated gusts to 25 kt
through about 6 AM, but in general, winds are already at or
below 22 kt for gusts and are expected to continue decreasing.

Today, winds become southwesterly with gusts generally less than
20 kt. There`s a small (20%) chance for some gusts up to 25 kt
around Grand Portage this afternoon, which could be hazardous
for small craft.

Wind speeds increase tonight and gusts to 25 kt are expected to
develop mainly along the North Shore and into the Outer Apostle
Islands into Tuesday with winds becoming northwesterly. Small
Craft Advisories may be needed. Winds are expected to decrease
again Tuesday afternoon.

For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...None.

&&

$$

DISCUSSION...JDS
AVIATION...JDS
MARINE...JDS