Duluth, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

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FXUS63 KDLH 182327
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
627 PM CDT Thu Jun 18 2026

.KEY MESSAGES...

- Isolated showers and a few, non-severe storms through early
  evening in far northern Minnesota, the Minnesota Arrowhead,
  and northwest Wisconsin.

- Scattered showers and storms with a cold/occluded front on
  Friday, with the best thunderstorm coverage along and south of
  the US Hwy 2 corridor.

- There is a 5 to 10% chance of strong to severe storms Friday
  afternoon and evening south of US Hwy 2 in northeast Minnesota
  and in northwest Wisconsin. Main hazards would be hail up to
  1 inch in diameter and wind gusts to 50 mph.

- Temperatures gradually warming each day into next week, but
  generally slightly below normal with highs in the mid 60s to
  mid 70s and low temperatures in the 40s to around 50 most
  nights. For comparison, normal highs are mid to upper 70s and
  normal lows are upper 40s to mid 50s.

&&

.DISCUSSION...
Issued at 1254 PM CDT Thu Jun 18 2026

Rest of Today - Tonight:

In the wake of a surface cold front, seasonably cooler air remains
over the Northland with highs topping out in the mid-60s to low 70s
this afternoon, warmest in NW WI. Weak shortwave troughing energy
aloft moving through the region along with cold air advection will
keep isolated to widely scattered showers and a few general storms
going through early this evening for the MN Arrowhead and portions
of NW WI. Rainfall amounts will be isolated and largely a few
hundredths of an inch or less, though any storms could produce a
quick tenth or two of an inch (20% chance). Northwest wind gusts to
15-25 mph diminish towards sunset this evening with winds becoming
light and variable to calm overnight. Also expect some patchy fog
development tonight given calming winds and clear skies,
particularly for areas that see any rain today. Widespread fog or
dense fog are not expected.

Friday:

A week mid/upper-level shortwave trough moves through as surface low
pressure slides along the international border and brings a
cold/occluded front west to east across the Northland. PWATS around
0.8-1.0" along with surface dew points around 50-55F will provide
enough moisture for scattered rain showers and thunderstorms to
develop on Friday along and ahead of the surface front. High-res
model forecast instability continues to trend higher for the
afternoon through mid-evening hours, with MLCAPE of 200-500 J/kg in
most of NE MN and 300-800 J/kg in the Brainerd Lakes east into NW
WI. The combination of higher instability in the south combined with
25-40 kt of bulk shear, steeper low-level lapse rates, and marginal
mid-level lapse rates around 6-6.5 deg C/km would support an
isolated, marginally strong to severe wind gust/hail threat with any
discrete storms that develop (5-10% chance). The hazards with the
strongest storms would be wind gusts up to 50 mph, hail up to 1" in
size, frequent lightning, and locally heavy downpours. Thunderstorm
intensity wanes towards sunset, so the window of strong to severe
storm potential is mainly in the 1 PM - 9 PM timeframe.
Precipitation then ends west to east in the evening to overnight
hours Friday night. Probabilities for >0.25" of rainfall on Friday
are 50-70% for much of NE MN along and west of the US Hwy 53
corridor, highest in north-central MN. These same areas have a 20-
40% chance for >0.5" of rainfall, mainly tied to locations where
thunderstorms move through.

Outside of showers and storms, expect increasing cloud cover on
Friday, then some clearing in north-central MN towards sunset as the
cold front moves through. Expect daytime wind gusts to around 15 mph
and high temperatures in the mid 60s to low 70s.

This Weekend:

Surface high pressure moving east from the Dakotas slides through
the Upper Midwest on Saturday and east into the Great Lakes on
Sunday. This will lead to a predominately drier air mass over the
Northland. With that said, a cut-off low aloft that has been
churning near the northeast Manitoba/far northwest Ontario border
will eventually dig southeast towards Lake Superior sometime late
Saturday or Sunday, though ensemble members and deterministic mid-
range models are in disagreement on how quickly the low moves and
how far south it digs, as is typically the case with these cut-off
lows. Therefore, we can`t completely rule out some isolated rain
shower potential (10-40% chance) mainly in the MN Arrowhead on
Saturday or to a lesser extent on Sunday, but precipitation coverage
and amounts should be limited in nature due to the overall drier air
mass in place.

Temperatures warm a few degrees for this weekend with highs in the
mid 60s to mid 70s and partly cloudy to mostly sunny skies.
Northeast winds on Sunday should produce slightly cooler
temperatures near Lake Superior and the Twin Ports.

Early Next Week:

Fairly good agreement in the pattern aloft for early next week as a
mid/upper-level trough currently (i.e. today/Thursday) over the Gulf
of Alaska dives southeast across British Columbia on Friday and the
southern Canadian Prairies this weekend. That system then slides
east/southeast through southern Saskatchewan, Manitoba, and the
Upper Midwest through the first half of next week. An associated low
pressure system also moves through during the same timeframe, with a
cold front extending south through the High Plains on Monday, to
western MN by Tuesday, and through our region sometime late Tuesday
into Wednesday. Ahead of this system, northeast surface winds are
likely on Monday before becoming southerly on Tuesday. Temperatures
remain pretty consistent in this timeframe in the upper 60s to mid
70s, with slightly cooler temperatures near Lake Superior. Warm
advection/isentropic ascent ahead of this front should bring in
widespread showers and embedded storms on Tuesday from west to east,
then along and ahead of the front late Tuesday into early Wednesday
as the front moves through. Still a bit early to pin down potential
for strong or severe weather with this system, but the origin of
this system in the Pacific northwest combined with a lack of
adequate Gulf moisture from our south favors a more limited
instability setup and weaker storms. Cyclonic flow behind the
departing low/front on Wednesday would also support lingering
scattered shower and storm chances.

Late Next Week and Beyond:

Models diverge in the mid/upper level pattern for the latter half of
next week into next weekend, but the latest CPC outlooks for late
June favor slightly above normal precipitation with near normal
temperatures favored.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 627 PM CDT Thu Jun 18 2026

Showers are passing over DLH right now and may linger for the
next hour or two. There`s a 20% chance for a shower to pass over
HYR in the next two hours, but confidence isn`t high enough to
mention in the TAF at this time. Otherwise, expect winds to
lighten up around sunset with VFR conditions expected through
the night.

The next concern will be showers and thunderstorms to pass
through starting at BRD mid-morning and spreading east to the
remaining terminals through the afternoon and early evening. The
best chances for strong to perhaps severe storms will be at
BRD/HYR where large hail will be possible (~5% chance).
Otherwise, expect some MVFR to possibly IFR conditions at times
as showers and storms pass through. Exact timing of storms is
still not precise, but midday through the afternoon is broadly
when they are expected.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 1254 PM CDT Thu Jun 18 2026

Westerly winds at 5 to 15 kts today become northwesterly at 5
to 15 kts for this evening and tonight. Isolated showers and a
few non-severe thunderstorms will be possible this afternoon
into this evening along the North Shore, primarily east of
Taconite Harbor. Winds back to southwesterly on Friday at 5 to
15 kts, with some gusts of 15 to 20 kts from Grand Marais to
Grand Portage Friday afternoon. Winds become westerly at 5 to 10
kts Friday night. Scattered showers and non-severe
thunderstorms will be possible again during the afternoon and
evening hours in the western arm of Lake Superior, with the
best chance for any thunderstorms near the Twin Ports. Southwest
winds develop again for Saturday at around 10 kts or less.

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

&&

.FIRE WEATHER...
Issued at 1254 PM CDT Thu Jun 18 2026

Scattered light rain showers across far northern Minnesota, the
Minnesota Arrowhead, and northwest Wisconsin for this afternoon
into early evening. Isolated, non-strong or severe storms will
occur at times, too. Expect only a few hundredths of an inch of
rain where precipitation does fall, and locally 0.1-0.2" where a
thunderstorm moves overhead. Min RH remains at or above 40%
across the areas today and recovers to 85-100% tonight.

Better coverage of scattered to widespread showers storms are
expected on Friday along and ahead of a cold/occluded front,
especially for north- central Minnesota, the Brainerd Lakes, and
east into northwest Wisconsin. Around or less than 0.1"
expected for the Arrowhead and far northern Minnesota, but
0.1-0.4" elsewhere. Areas that see storms could see localized
amounts in excess of 0.5", as well. A few storms could be strong
to severe in the Brainerd Lakes east to northwest Wisconsin.
Hail up to 1", wind gusts to 50 mph, frequent lightning, and
locally heavy downpours are the hazards with the strongest
storms. Min RH is once again expected to be at or above 40% on
Friday.

Mainly conditions return for Saturday, but RH values are
currently forecast to dip to 35-50% across the area. 20-50%
chances for isolated showers and an embedded weak storm or two
remain on Saturday in the tip of the Arrowhead. Winds will also
be lighter into the weekend at 5 to 15 mph out of the northwest
on Saturday and northeast on Sunday, with daytime winds strongest
in the afternoon both days. Temperatures will be in the 60s and
lower 70s through Saturday then warming into primarily the low
to mid 70s for Sunday into next week.

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...Rothstein
AVIATION...JDS
MARINE...Rothstein/BJH
FIRE WEATHER...Rothstein