357
FXUS63 KDLH 210835
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
335 AM CDT Fri Aug 21 2026

.KEY MESSAGES...

- Patchy fog, locally dense, continues early this morning. This
  may lead to travel impacts for the Friday morning commute,
  with localized areas seeing visibility as low as one quarter
  of a mile.

- Scattered showers with isolated non-severe thunderstorms will
  be possible this afternoon and evening, especially in the
  Arrowhead. A strong storm or two may occur today, capable of
  producing small hail and gusty winds to 40 mph.

- Pleasant weather conditions are forecast this weekend with comfortable
  high temps in the 70s and abundant sunshine. Additional
  shower and thunderstorm chances arrive early next week on
  Monday night into Tuesday.

&&

.DISCUSSION...
Issued at 335 AM CDT Fri Aug 21 2026

A shortwave is currently propagating through the area early this
morning, with the scattered and thunderstorms that impacted the CWA
yesterday evening now moving downstream. In the wake of this precip,
patchy fog and low stratus have developed early this morning.
Localized dense fog is also occurring early this morning, with
visibility as low as one quarter of a mile. This fog is expected to
linger until shortly after sunrise, leading to travel impacts
for the Friday morning commute. Opting against issuing a Dense
Fog Advisory at this time, as dense fog has been fairly sporadic
and intermittent.

Today will see more benign conditions compared to yesterday as
the sfc low continues to move east and the CWA sits under a
pattern of northwest flow aloft. A second 500mb shortwave is
expected to propagate into the Upper Great Lakes region this
afternoon and evening, which will bring a chance for scattered
showers into the area. Isolated thunderstorms will also be
possible, as MLCAPE this afternoon and evening increases to
200-1000 J/kg and modest 0-6km bulk shear of 25-30 knots occurs.
This instability likely won`t be enough to generate severe
storms, as hi-res model soundings show a fairly skinny CAPE
profile. However, a strong storm capable of producing small hail
and gusty winds to 40 mph will still certainly be possible
today. Expect showers and storms to come to an end by tonight as
the shortwave continues to propagate downstream.

Pleasant summer weather is anticipated this weekend as high pressure
builds into the region and northwest flow keeps high temps in the
70s with comfortable humidity. While min RH does trend on the drier
side on Sunday in the 30 to 40% range, fire weather concerns will be
mitigated by the light and variable winds expected on Sunday. Enjoy
the weather this weekend!

This dry and pleasant weather continues through much of the day
Monday, albeit with slightly warmer temps as southerly flow
provides WAA. Cloud cover will be increasing through the day on
Monday as vertically-stacked low pressure propagates from the
Canadian Prairies into the Great Lakes region. This low pressure
will bring additional chances for showers and thunderstorms on
Monday night through Tuesday. On Wednesday, additional shower
activity will be possible in the post-cold front environment.
The latter half of next week is favored to see a return of high
pressure and pleasant summer high temps in the mid 70s to around
80 degrees.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1231 AM CDT Fri Aug 21 2026

Isolated thunderstorms in portions of northwest WI early this
morning will be coming to an end over the next couple hours. Areas
of fog are developing behind this rainfall, which will be impacting
all terminals early this morning. Expect areas of IFR to LIFR
conditions to start the day, improving to VFR later this morning
into the afternoon. Scattered rain showers will be possible late in
the afternoon into the evening, although conditions will likely
remain VFR.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 335 AM CDT Fri Aug 21 2026

Patchy fog is expected early this morning, clearing shortly after
sunrise. An isolated shower or thunderstorm will be possible this
evening, especially along the North Shore. While severe storms are
not expected, small hail may occur under a strong storm or two.
Light and variable winds today become northwest tonight into
Saturday with high pressure moving into the area. These northwest
winds on Saturday preceding the high pressure will be breezy in the
afternoon, gusting 15-20 knots. Light and variable winds return on
Sunday, with gusts forecast to remain under 10 knots.

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

&&

.FIRE WEATHER...
Issued at 335 AM CDT Fri Aug 21 2026

Northwest winds are expected today through Saturday following the
cold frontal passage occurring early this morning. High temps today
will be in the 70s for most with elevated min RH values of 45% or
higher. A secondary cold front arriving late this afternoon into the
evening will bring a chance for scattered showers with isolated
thunderstorms. While severe storms are not expected, strong storms
capable of producing small hail and gusty, erratic wind gusts to 40
mph will be possible, especially in the Arrowhead.

High pressure builds this weekend, with Sunday currently expected to
be the driest day. Min RH on Sunday will be as low as 35%, although
light and variable winds limit fire weather concerns. Additional
showers and thunderstorms are forecast to arrive Monday night into
Tuesday. Moderately dry min RH as low as 35% does linger on Monday
in the Arrowhead and northwest Wisconsin, although cloud cover will
be increasing through the day.

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...Unruh
AVIATION...Unruh
MARINE...Unruh
FIRE WEATHER...Unruh