215
FXUS63 KDLH 252323
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
623 PM CDT Fri Sep 25 2026

.KEY MESSAGES...

- Dense fog may redevelop tonight around the Twin Ports and
  through the St. Louis River Valley.

- Light rain is expected Saturday morning over central and
  portions of north-central Minnesota. Rain will move slowly
  eastward through Sunday morning. The greatest rain amounts
  will be over central and north-central Minnesota.

- A more organized system will bring a higher chance of
  widespread soaking rain Monday night through Tuesday.

&&

.DISCUSSION...
Issued at 256 PM CDT Fri Sep 25 2026

SYNOPSIS:

A broad upper-level ridge bisected the CONUS this afternoon
with a trough of low pressure over the East Coast and a digging
trough over the Pacific Northwest. A subtle mid-level trough was
over the Dakotas east into the Midwest with a stronger
reflection at 700 mb. Surface high pressure was centered over
Lake Huron while an elongated surface trough stretched along the
eastern periphery of the Rockies.

THIS AFTERNOON AND TONIGHT:

Low stratus was being replaced by diurnal Cu over the Northland
this afternoon. Expect generally mostly cloudy skies for most
locations. Duluth, areas along the Lake Superior shoreline and
portions of the Arrowhead will see the least cloud cover.
Anticyclonic flow over the region will persist tonight. Low-
level isentropic ascent should be sufficient to regenerate low
stratus and fog again tonight. The Twin Ports are the most
likely area to see dense fog Saturday morning.

SATURDAY AND SUNDAY:

The mid-level trough will lift northward across the Upper
Midwest Saturday as the upper-level trough digs into the
Rockies. Modest height falls reveal forcing for ascent which is
also reflected in isentropic analysis over the region. A strong
southerly low-level jet is forecast over western Minnesota which
will provide low-level convergence and a persistent moisture
feed. Light rain will develop tonight over western Iowa and
spread north into central Minnesota Saturday morning. The upper-
level trough will slowly propagate eastward while the mid-level
trough lifts into northwest Ontario by 06Z Sunday. Rain will
gradually advance eastward in response. High pressure to the
east will advect dry air below the cloud layer from the
southeast which will limit the progression of the rain chances.
This scenario is similar to what we saw Thursday. Gusty
southerly winds are expected, particularly in rain, as the
stronger momentum from the low-level jet mixes down to the
surface starting early Saturday morning and weakening Saturday
evening.

Temperatures on Saturday will reach the low 60s (a few degrees
below normal) near the Brainerd Lakes where rain is expected
most of the day to the low to middle 70s in northwest Wisconsin
(as much as 12 degrees above normal).

With the high pressure situated to our east, northeast winds
over western Lake Superior are forecast to strengthen during the
day to 10-15 knots with gusts to around 20 knots. The favorable
wind direction and funneling between the high terrain of the
north and south shores of Lake Superior will create a risk of
rip currents for the beaches of the Twin Ports.

Light rain will advance eastward into the Arrowhead and
northwest Wisconsin Saturday night and early Sunday morning.
Forcing for ascent will diminishes as the mid-level trough
pushes farther into northwest Ontario. Skies are forecast to
gradually clear from west to east on Sunday. Temperatures trend
warmer in our west with highs in the middle 60s to near 70
degrees. The Arrowhead and northwest Wisconsin will be cooler
due to the slower departure of clouds and lingering light rain
showers.

MONDAY THROUGH NEXT FRIDAY:

By early next week the trough and cutoff low over New England
will remain in place with an elongated upper-level ridge
stretching from the southern Plains into Quebec. A longwave
trough is forecast to move into the northern Plains and Canadian
Prairies Monday night into Tuesday which brings another chance
of rain to the Northland. The persistence of the eastern cutoff
low will result in long moisture trajectories from the Baja
Pacific into the western Great Lakes. Tropical moisture from
Hurricane Polo is forecast to slip around the southern periphery
of the Rockies and spill into the Plains and Midwest ahead of
the Tuesday system. That would set the stage for greater rain
chances as the trough moves into our area and raise the
potential for excessive rainfall. Timing isn`t quite as
favorable with the 12Z models which focus rainfall over the
Dakotas into northwest Ontario Monday night and the Midwest on
Tuesday. On the other hand, models struggle to handle the
breakdown of blocking patterns once they are established and
that could play a complicating factor in rain chances early next
week.

Wednesday and beyond features additional small chances of
precipitation and near to slightly above normal temperatures.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 623 PM CDT Fri Sep 25 2026

Cloud cover continues to persist across the region with largely VFR
conditions. Small pockets of MVFR ceilings are still being observed
but by in large the region is VFR. Upslope flow over Lake Superior
may lead to another round of fog tomorrow morning impacting DLH
similar to what we saw today. Additionally, light rain is expected
to enter from the west tomorrow afternoon with MVFR ceilings
returning.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 256 PM CDT Fri Sep 25 2026

Light northeast winds of 5 to 10 knots are expected tonight.
Waves will be less than 2 feet. Fog may redevelop near the Twin
Ports and along the waters of the north shore early Saturday
morning. The fog may become locally dense with visibility less
than 1 mile. Northeast winds will strengthen to 5 to 15 knots
with gusts of 10 to 20 knots. The strongest winds will be found
in the southwest arm of Lake Superior near the Twin Ports. Waves
in the southwest arm will build to 2 to 4 feet. Wind and waves
diminish Saturday evening as light rain moves over the waters.
The rain will raise the potential for fog development once
again, which may become dense with visibility less than 1 mile.
Winds veer southerly Saturday night and should be light on
Sunday. A stronger system will approach the region Monday night
and Tuesday which may create conditions hazardous for smaller
vessels due to strengthening northeast winds.

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

&&

.FIRE WEATHER...
Issued at 256 PM CDT Fri Sep 25 2026

Fire weather concerns remain low for this forecast period.
Light rain spreads northward across central and north-central
Minnesota Saturday in a repeat of the conditions from Thursday.
Look for rain to gradually move eastward during the day into the
Arrowhead and northwest Wisconsin by early Sunday morning. Rain
amounts will be highest over central and north-central
Minnesota where 0.1 to 0.5 inches of rain is possible. Amounts
dwindle farther east as the rain fights dry air aloft moving in
from the southeast. Gusty southeasterly winds are forecast
Saturday. Sustained winds will range from 8 to 15 mph with gusts
of 15 to 25 mph. The strongest winds will be over central and
north- central Minnesota. Sunday will see rain depart the
Northland. Partly cloudy skies are expected with highs in the
low 60s to around 70 degrees. Afternoon RH values of 55-75% are
expected. Another chance of rain will move into the region
Monday night and Tuesday.

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

&&

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

&&

$$

DISCUSSION...Huyck
AVIATION...Britt
MARINE...Huyck
FIRE WEATHER...Huyck