508
FXUS63 KDLH 011833
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
133 PM CDT Thu Oct 1 2026

.KEY MESSAGES...

- Widespread frost and freeze conditions are expected tonight.
  Additional frost and freezing temperatures are possible again
  Friday night.

- Light rain is expected Saturday into Saturday evening,
  especially along the International Border.

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

&&

.DISCUSSION...
Issued at 132 PM CDT Thu Oct 1 2026

We have some mixed cloudscapes out there this afternoon with
departing mid and high level clouds over northwest Wisconsin and
some incoming stratocumulus along the International Border
associated with an upper-level trough. Some of those clouds will
persist overnight, mainly across the Arrowhead, with clearing
elsewhere. The challenge overnight is overnight lows and
figuring out just how cold it will get. We will have high
pressure moving in tonight, and most places should see clear
skies. However, at least some pressure gradient will persist
further east, keeping winds from becoming calm in parts of
northwest Wisconsin and especially along the North Shore with
some downslope flow. With that said, most guidance highly favors
temperatures falling to around or below 36 degrees for inland
areas tonight (70-90% chance) with lesser probabilities for
freezing or below temperatures (40-60% up north where Freeze
Warnings are already in effect and 20-50% for parts of interior
northwest Wisconsin). With all that in mind, I expanded Frost
Advisories to cover all zones except the North Shore, where
breezy conditions will probably prevent frost there even if
temperatures do get towards freezing for some places. Some
places within a Frost Advisory may not see frost, like around
the Brainerd Lakes or near Lake Superior. In addition, some
places in interior northwest Wisconsin could see freezing
temperatures, but confidence is not high enough that it will be
widespread enough to warrant Freeze Warnings. All that to say,
it should be cold tonight, and there will probably be some
locality to frost/freeze conditions, but in general, most places
will probably see some frost.

On Friday, expect quiet and sunny weather with high pressure and
seasonably cool temperatures. As high pressure moves east Friday
night, parts of the Arrowhead and northwest Wisconsin will still
be under the influence of that with mostly clear skies and light
winds. Additional frost/freeze headlines will likely be needed.
Further west in north-central Minnesota, southerly winds will
pick up a bit and temperatures won`t be quite as cold. Frost
won`t be as likely as a result. Instead, expect increasing
clouds with some showers moving in with an incoming shortwave
trough that`s expected to pass along the Canadian border. Models
continue to favor an area of mainly light rain developing and
targeting the International Border on Saturday with lingering
showers into Saturday evening. Rainfall amounts continue to look
not-so-impressive with most places picking up a tenth or two of
an inch at best.

A bit of rinse and repeat going into Sunday as a cold front
passes through Saturday night and we end up with cool northwest
flow on Sunday. High pressure settles in Sunday night, and we`ll
be looking at another widespread frost/freeze. Coverage of
freezing temperatures will probably be much greater compared
to tonight, though some areas (like near Lake Superior) may
still evade a hard freeze.

Southerly flow will likely bring warm and above normal
temperatures early next week starting on Monday. Rain chances
are looking pretty sparse next week, but it`s possible there
could be some sprinkles or light rain from time to time.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1239 PM CDT Thu Oct 1 2026

VFR ceilings are expected through the period. There is a
possibility (~25% chance) that some brief MVFR ceilings could
affect INL later this afternoon and evening as an area of clouds
in Ontario drops south, but most observations underneath the
cloud deck are VFR right now, so that`s what`s most likely at
INL. Breezy conditions will persist through the afternoon, then
winds lighten up overnight. A bit of downsloping at DLH may
cause an uptick in breezy conditions again later tonight with
gusts between 15 and 20 kt, lasting into Friday morning.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 132 PM CDT Thu Oct 1 2026

Breezy conditions are happening this afternoon, so Small Craft
Advisories will remain in effect through this afternoon and
evening. Winds will decrease this evening as high pressure moves
in, but only slightly, and we will have to keep an eye on
conditions along the North Shore as there will be some
downsloping winds. It`s possible there could be some brief 20-25
kt gusts from Grand Marais to Grand Portage later tonight into
early Friday morning. Winds become light Friday into Saturday
with high pressure passing through. Some showers are possible
Saturday afternoon and evening. Southerly winds will become a
bit breezy, then switch to westerly and northwesterly overnight
and into Sunday as a cold front passes through. Expect some
strong winds Sunday with gusts to around 25 kt with northwest
winds. Small Craft Advisories will likely be needed.

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

&&

.FIRE WEATHER...
Issued at 132 PM CDT Thu Oct 1 2026

Expect dry conditions for the rest of today and again on Friday.
Unlike today, winds will be relatively light on Friday with
gusts up to 10-15 mph. Min RH is expected to fall into the
30-45% range, lowest in northwest Wisconsin with high pressure
in place. Fire weather conditions may be slightly elevated due
to the dry air mass. As a system passes by on Saturday, expect
some light rain mainly along the Canadian border, but clouds and
higher moisture elsewhere. A cold front passes through Saturday
night, bringing breezy northwest flow and drier conditions again
on Sunday and Monday as high pressure passes through. Some
slightly elevated fire weather conditions may return with RH
falling to 30-45% Sunday and breezy northwest winds. Drier
conditions on Monday, but with lighter winds.

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
     MNZ025-033-034-036>038.
WI...Frost Advisory from midnight tonight to 9 AM CDT Friday for
     WIZ006-009.
MARINE...Small Craft Advisory until 7 PM CDT this evening for
     LSZ140>147.
     Small Craft Advisory until 10 PM CDT this evening for LSZ150.

&&

$$

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