270
FXUS63 KDLH 041731
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1231 PM CDT Sat Oct 4 2025

.KEY MESSAGES...

- Hot weather is expected today. High temperatures in the 80s may
break records at several sites.

- Strong southerly winds will create near-critical fire weather
conditions today and Sunday.

- Scattered showers and non-severe thunderstorms are possible Sunday.

- A return to fall weather with frost possible at times into  next
week.

&&

.UPDATE...
Issued at 644 AM CDT Sat Oct 4 2025

Updated Marine Discussion Below

&&

.DISCUSSION...
Issued at 348 AM CDT Sat Oct 4 2025

There`s some light onshore flow from Lake Superior and
marine fog and low stratus moving in mainly around the Twin Ports
and South Shore. Webcams and satellite suggest that dense fog isn`t
widespread, but there have been some sporadic quarter mile
observations at Ashland and La Pointe, and we`re down to a mile at
the Duluth airport. The fog will probably be around in its current
spatial distribution through around sunrise, then largely mix out
except perhaps some lingering over the open waters.

What would be a reasonably hot day in July is expected today in
October. We will be in the center within an axis of very warm air
advection coming at us from the northern Mexico/New Mexico/Texas
areas. Models are all in good agreement with highs in the mid 80s
for most and some upper 80s in the Brainerd Lakes to
Hinckley/Grantsburg areas. While it will be hot, we will be several
degrees shy of needing any heat advisories. So, the best guidance is
to drink plenty of water and enjoy one of the last July-like days in
October. Several high temperature records and even some high minimum
temperature records may be tied or broken.

Fire weather will be a concern today with gusty south winds
sustained around 15-20 mph and gusting to around 35 mph. While RH is
not expected to drop below 40 percent, the gusty winds are expected
to create near-critical fire weather conditions, mainly from the
Brainerd Lakes to Hinckley areas.

Other than the heat, we should have some high clouds around today,
but otherwise we will have plenty of capped instability that
shouldn`t result in any convection. The only place that could
perhaps see a stray shower or storm late this afternoon would be far
northwest Koochiching county, but most of the shower/storm activity
should remain further northwest associated with a stationary front.

While the main frontal forcing and a low pressure system should keep
most precipitation to our northwest tonight and into Sunday, we will
see a strong low-level jet develop tonight along with a passing
upper level trough. We might see winds approaching 50-60 kt at 3-5
kft above the surface! Some scattered showers and perhaps a non-
severe storm or two could develop as a result.

On Sunday, we`ll have one last hurrah of the warm weather before
fall makes a swift return. Highs in the 70s to low 80s are expected
ahead of a potent cold front that will make its way through during
the afternoon. Temperatures should start to cool down during the
afternoon with the frontal passage for north-central Minnesota
areas. Scattered showers and thunderstorms will be possible, though
sounding profiles for instability look rather capped and
unimpressive (maybe a few hundred J/kg of MUCAPE). Nevertheless,
some organized lines of showers and storms may be possible as the
front moves through.

Any shower/storm activity may not get its act together until the
afternoon, and we`ll have another day of strong southerly winds. We
should see more widespread sustained 20 mph winds, which will lead
to near-critical fire weather conditions. Gusts in the 30-35 mph
range with some localized gusts to 40-45 mph are possible.

We formally welcome fall back to the Northland on Monday with
westerly winds and highs in the 50s to low 60s. High pressure passes
through briefly, and we might have some localized frost returning to
the forecast Monday night and maybe more widespread Tuesday night.
Broad ridging may return later in the week, bringing a gradual warm
up and some rain chances around Thursday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1222 PM CDT Sat Oct 4 2025

VFR conditions are expected for the TAF period. A stationary
front sitting in northwestern Minnesota will lead to storms
later tonight and a few stray storms could move over INL tonight
into tomorrow morning with multiple waves of storms to the west.
LLWS is expected as well tonight for all sites except INL,
which may see a few hours of LLWS in the early morning hours.
Otherwise, main concern is increasing winds out of the south to
southwest throughout today and into Sunday. Gusts of 20 kts
today will increase to around 30 kts for Sunday.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 644 AM CDT Sat Oct 4 2025

Updated to issue a Dense Fog Advisory for the head of the lake
until 15z (10 AM CDT). Fog has been persistent despite model
trends suggesting that it should dissipate. Still anticipate
that it will eventually lift shortly after sunset, but it may
take several hours.

Previous Discussion:
Light northeast flow this morning is
expected to switch to southerly to southwesterly later this
morning. Wind gusts in the 20-25 kt range are expected to
develop by around midday around the Twin Ports and South Shore
and will expand to the North Shore later this evening. This will
lead into stronger winds that may approach gale criteria on
Sunday. Small Craft Advisories and a Gale Watch are in effect.
Wave heights are expected to gradually grow to about 3-5 ft for
most places going into Sunday, but higher waves to around 8 ft
or so around Grand Marais to Grand Portage. Winds gradually
lighten up going into Monday with a cold front passing through
and causing winds to become more westerly.

Aside from wind/waves, there is a 20-30% chance for some showers and
non-severe thunderstorms Sunday into Sunday evening.

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

&&

.CLIMATE...
Issued at 348 AM CDT Sat Oct 4 2025

Hot weather is expected today. Record high and record high
minimum temperatures are in jeopardy of being broken. Below are
the records and forecast temperatures for today and Sunday that
could potentially be broken or tied.

Record High Temperatures:

October 4: Forecast Current Records
KDLH:      84       83/1922
KINL:      85       82/2011
KBRD:      87       82/2011
KHIB:      85       78/2011
KASX:      87       90/1922


Record Warm Low Temperatures:

October 4: Forecast Current Records
KDLH:      57       58/1914
KINL:      63       60/1914
KBRD:      68       60/1914
KHIB:      61       54/1969

October 5:
KASX:      58       56/1975

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 10 AM CDT Sunday for LSZ121-144>148-
     150.
     Gale Watch from Sunday morning through Sunday evening for
     LSZ121-140>148-150.
     Small Craft Advisory from 10 PM this evening to 10 AM CDT
     Sunday for LSZ140>143.

&&

$$

UPDATE...JDS
DISCUSSION...JDS
AVIATION...KML
MARINE...JDS
CLIMATE...JDS