Duluth, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

847
FXUS63 KDLH 121745
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1245 PM CDT Tue Aug 12 2025

.KEY MESSAGES...

- Few showers and storms are possible near the International
  Border this afternoon, with smokiness returning to the
  Northland this evening.

- Cooler and less humid conditions expected today and Wednesday.

- Chances for showers and storms return Wednesday night, with an
  active pattern expected through the weekend.

&&

.DISCUSSION...
Issued at 337 AM CDT Tue Aug 12 2025

A line of showers and storms moved into the Northland last night
and with the loss of daytime heating has mostly diminished early
this morning. Some light rain lingers over portions of the North
Shore, but otherwise, low clouds and patchy fog will persist
over the Arrowhead through early morning. A cold front is slowly
moving westward into the region this morning, and currently
stretches from near Lake of the Woods to Bemidji to near
Aberdeen. This front will continue eastward today, as an upper
trough swings through the Northland. Expect some redevelopment
of showers and storms near the International Border and across
the Arrowhead. Bulk shear of 30-40kts will sustain updrafts and
with cooling temps aloft might see a strong storm or two.

Behind the front, cooler and drier air will filter southward,
providing a relief to the mugginess felt the last few days.
However, another wave of Canadian wildfire smoke will also
arrive, with haziness and reduced air quality expected by this
evening and through at least Wednesday morning.

Wednesday night into Thursday, broad upper level ridging will
extend across much of the southern CONUS, keeping an active
westerly flow pattern stretching from the Pacific Northwest and
across the Northern Plains. The first in several impulses will
arrive early Thursday, with good moisture transport back into
the Northland. Lapse rates and shear profiles are weak through
the morning hours and early afternoon, and expect mostly
scattered rain showers across western portions of the forecast
area. Thursday evening, a stronger shortwave and cold front
move across the Red River Valley, and expect an increase in
thunderstorm coverage to our west in response to steepening
lapse rates and increasing wind fields, during peak heating. A
line of showers and storms will move into the north central
Minnesota Thursday night, and similar to last night, a
weakening trend is possible given a low level cap and loss of
daytime heating.

The cold front will linger over the area through the weekend,
and with upper level impulses within active westerly flow,
chances for showers and storms will remain in the forecast.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1245 PM CDT Tue Aug 12 2025

VFR conditions prevail across the Northland early this afternoon
with some pockets of MVFR ceilings and visibilities due to
clouds and smoke. This next batch of smoke doesn`t look as
intense as previous bands, so not thinking we`ll see much more
than MVFR conditions from it. However, it will likely aid in
fog/smog formation Wednesday morning at HIB, BRD and HYR mainly
with MVFR or lower visibilities. A few isolated thunderstorms
will be possible over the next few hours at INL but are not
expected to be strong or severe. High pressure builds in tonight
and Wednesday with winds becoming very light following gusty
northwesterly winds this afternoon.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 337 AM CDT Tue Aug 12 2025

Southwesterly winds will increase today across western Lake
Superior. Specifically along portions of the North Shore, with
southwesterly funneling between Isle Royale and the mainland, gusts
of 25kts and wave heights of 2-4ft are possible. A Small Craft
Advisory is in effect for the zone covering Grand Marais to
Grand Portage, valid from mid morning through late afternoon.

Winds become westerly then northwesterly tonight as a cold front
moves through the area. Speeds diminish through the night, with
gusts of 15-18kts along portions of the North Shore due to
downsloping.


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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 4 PM CDT this afternoon for LSZ140.

&&

$$

DISCUSSION...HA
AVIATION...BJH
MARINE...HA