529
FXUS63 KDLH 010538
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1238 AM CDT Thu Oct 1 2026

.KEY MESSAGES...

- Widespread frost/freeze conditions are expected Thursday
  night into Friday morning.

- A chance for rain on Saturday, especially along the
  International Border.

- Another widespread frost/freeze is likely Sunday night into
  Monday morning.

- More rain is possible early next week.

&&

.DISCUSSION...
Issued at 1254 PM CDT Wed Sep 30 2026

Clouds continue to clear from west to east this afternoon as dry
air filters in and a cold front will gradually pass through into
tonight. Strong northwesterly cold air advection will develop
with a tightening pressure gradient, leading to blustery
conditions on Thursday. Temperatures won`t get overly chilly
tonight, but some lows around 40 are possible up around
Koochiching county. The next cold night will be Thursday night
into Friday as a surface high moves in from the west. This won`t
be a perfect radiational cooling night as we should have some
winds still sticking around, but we should still have widespread
temperatures in the 33 to 36 degree range and some areas falling
to or below freezing, especially the usual cold spots and also
more widespread in north-central Minnesota (40-60% chance for
temperatures falling below freezing there). Widespread frost
headlines will likely be needed, as well as some freeze
headlines.

On Friday, look for a seasonably cool and dry day with highs in
the 50s/60s. There will be at least localized concern for near
freezing and freezing temperatures again Friday night,
especially in northwest Wisconsin and the tip of the Arrowhead
where the influence of departing high pressure will still be
there. Warm air advection will develop with southerly flow
starting Friday night, however, so expect increasing clouds in
northeast Minnesota. A clipper is still looking like it will
pass through on Saturday, with an axis of mainly light rain
looking like it will target the Canadian border. Overall,
rainfall amounts still look quite light from this. A few places
could sneak up to a quarter of an inch total, but less for most
places that see rain. The rain may be pretty limited in coverage
to the Iron Range and points north.

Another cold front will pass through going into Sunday,
resulting in another seasonably cool day and breezy northwest
winds. High pressure moves in again Sunday night, and with this,
we`ll be looking at one of the coldest nights of the fall season
so far. Widespread temperatures at or below freezing are likely
(40-80% chance). Areas around Lake Superior may be spared from
a freeze, but it will probably be only a few miles inland where
freezing temperatures are found. This may be a season-ending
freeze for many places. Probabilities of temperatures 28 degrees
or lower are 10-30% at this time, so we will have to wait a few
days and see how trends change.

There will be an upper-level trough just northeast into Ontario,
producing a few rain/snow showers, and parts of the UP might see
some of their first lake-effect rain/snow showers. We should
remain dry into Monday with sunshine as high pressure passes
through.

Southerly flow and an upper-level trough could bring more rain
chances to the region early next week along with moderating
temperatures.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1236 AM CDT Thu Oct 1 2026

Light west winds tonight increase and gust to 17-22 knots
Thursday daytime under VFR conditions. The exception is ongoing
fog for the next few hours in northwest Wisconsin before a dry
cold front passes through and that fog is expected to dissipate.
A weak and small weather disturbance moves through northwest
Ontario Thursday evening and brings about some afternoon and
evening low-end VFR sky cover along the Borderlands.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 1254 PM CDT Wed Sep 30 2026

A dense fog advisory continues this afternoon for parts of the
North Shore this afternoon. The current headline from Taconite
Harbor to Grand Portage runs into this evening. Webcam around
Grand Marais shows greatly improving conditions, though
satellite still suggests some fog further up the shore. Will
hold the current headline as-is for a little while longer this
afternoon to monitor trends while some moisture remains in
place, but it`s very possible that this headline may be allowed
to expire several hours early if the clearing trend persists.

Tonight, a cold front will pass through, bringing a wind
direction change to northwesterly. Conditions become breezy into
Thursday with gusts in the 15 to 20 kt range, and perhaps
locally higher along the North Shore with some downsloping.
Right now, it looks like gusts will remain below Small Craft
Advisory criteria or perhaps there could be a 1 to 3 hour period
of gusts around 22 kt Thursday afternoon. No headlines will be
issued now, but it`s possible that a short-duration Small Craft
Advisory may be needed for parts of the North Shore Thursday
afternoon. This may extend into the outer Apostle Islands into
Thursday night as northwest winds persist and colder air works
its way over the lake. The next chance for any potentially
hazardous conditions won`t arrive until Saturday, when some
breezy southerly winds may be possible.

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

&&

.FIRE WEATHER...
Issued at 1254 PM CDT Wed Sep 30 2026

Drier air moves in this afternoon and tonight with a cold front
passing through. Thursday, expect conditions to become pretty
dry, especially in northwest Wisconsin where some 25 to 35 min
RH values are expected. Winds will be a bit breezy Thursday as
well, though the strongest winds gusting from 15 to 25 mph will
be in northeast Minnesota (where RH will be a little higher,
from around 35 to 50%) and gusts to around or just over 15 mph
in northwest Wisconsin. Some elevated fire weather conditions
may be possible, especially in northwest Wisconsin and possibly
along the North Shore where downsloping may result in locally
lower humidity and breezy conditions.

Another dry day is expected Friday with min RH falling to 35 to
45%, but with lighter winds. Expect more clouds and some rain
Saturday into Saturday night, mainly Iron Range and north.
Rainfall amounts will generally be less than a quarter inch
where it does rain (most places in the region will remain dry).
Expect another cold front going into Sunday, which may result in
some blustery northwest winds and dry air with RH falling below
40% for many places Sunday into Monday.

See the Fire Weather Forecast product for a more thorough
breakdown of fire weather conditions.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Freeze Warning from midnight tonight to 9 AM CDT Friday for
     MNZ010-011-019.
     Frost Advisory from midnight tonight to 9 AM CDT Friday for
     MNZ012-018-026-035.
WI...Frost Advisory from midnight tonight to 9 AM CDT Friday for
     WIZ001>004-007-008.
MARINE...Small Craft Advisory from 1 PM this afternoon to 7 PM CDT this
     evening for LSZ140>147.
     Small Craft Advisory from 1 PM this afternoon to 10 PM CDT
     this evening for LSZ150.

&&

$$

DISCUSSION...JDS
AVIATION...NLy
MARINE...JDS
FIRE WEATHER...JDS