Duluth, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

980
FXUS63 KDLH 260852
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
352 AM CDT Tue May 26 2026

.KEY MESSAGES...

- Warm, summer-like, temperatures continue today. Highs will be
  in the 80s with a few values near 90. Slight cool down for
  Wednesday and Thursday before heat returns Friday.

- A few clusters of thunderstorms are expected this afternoon
  and evening generally along and south of US-2 in Minnesota and
  Wisconsin. The isolated to scattered nature of the storms
  warrants a 10-30 percent chance of rain at this time. A few
  storms may be strong to severe with hail of penny to half-
  dollar size (0.75 to 1.25 inch diameter) and wind gusts of 40
  to 60 mph.

- Prominent lake breeze Wednesday will provide cooler
  temperatures near Lake Superior. The Brainerd Lakes should see
  temps in the middle and upper 80s with upper 60s and 70s
  closer to Lake Superior.

- Fire weather concerns increase later this week under high
  pressure and warm temperatures.

&&

.DISCUSSION...
Issued at 349 AM CDT Tue May 26 2026

Synopsis:

Split upper-level flow will persist through the weekend into
early next week. A deep 300 mb trough along the Pacific coast
will become a cutoff low by tonight. The northern stream of the
subtropical jet will be displaced northward into far northern
Canada as a negatively-tilted ridge builds over the Plains and
Canadian Prairie Provinces through the weekend. An upper-level
trough will dig into eastern Canada and New England. Several jet
streaks will rotate through the flow late this week. Several
areas of surface high pressure will progress southeastward from
far northern Canada through Ontario toward New England. The
upper-level ridge will persist into early next week.

Today and tonight:

Rising mid-level heights over the upper Midwest today will
provide weak subsidence above a slow-moving and diffuse cold
front over the Northland. Ample sunshine and southerly flow
south of the front will create very warm temperatures today,
likely the warmest temperatures of the week. Highs will climb
into the upper 70s along the South Shore to the upper 80s to low
90s farther inland. Temperatures will be cooler along the
Canadian border, north of the cold front. Southerly winds will
keep the Arrowhead a bit on the cooler side thanks to cool air
advection from Lake Superior. These values are near record highs
for Brainerd and Hibbing today. International Falls could run
at another high temperature record if temps trend warmer than
forecast. Near-critical RH values of less than 25% are forecast
from near Walker and Longville northeast to Ely and Sea Gull
Lake. Winds should be light over those areas around 5 to 10 mph.

Along and south of the cold front light southerly winds will
continue Theta-E advection with dewpoints in the upper 50s to
low 60s. The combination of heat and moisture will lead to
MLCAPE values of 1000-2000 J/kg by late afternoon amidst 0-6 km
bulk shear values of 25-30 knots. Mid-level lapse rates of -6.5
to -7 C/km are forecast with a noticeable layer of drier air in
the mid-levels. Given the diffuse nature of the cold front,
several clusters of thunderstorms are forecast for this
afternoon. Uncertainty in the location of the storm develop
means PoPs are generally in the 10-30% range as of this morning.
Widespread storms are not anticipated.

One potential enhancing factor is the presence of a
convectively generated shortwave trough evident in GOES-East
Band 8 water vapor imagery over southeast South Dakota,
northeast Nebraska, and northwest Iowa. Additional storms
developed farther west toward Pierre SD since 08Z. That
shortwave trough should propagate northeastward toward central
Minnesota and northwest Wisconsin through early afternoon and
could counteract the broad subsidence from rising mid-level
heights. Should that wave move into central Minnesota and
northern Wisconsin, there would be a localized increase in bulk
shear which would support better organized storms. If the
shortwave arrives too early or propagates easterly instead of
northeast, the weak bulk shear combined with moderate
instability would support pulse storms capable of penny to half-
dollar size (0.75 to 1.25 inch diameter) hail and downburst
wind gusts of 40 to 60 mph. Trends will need to be monitored
through the day to re-evaluate this threat.

Wednesday:

The surface boundary sags still farther south as Canadian high
pressure pushes south toward the Great Lakes. Winds for all of
the area will turn east to northeast. A slightly tighter
pressure gradient will translate into stronger northeast winds
over western Lake Superior, with gusts up to 25 mph. This will
generate a prominent lake breeze with temperatures to cool
significantly, with 60s and lower 70s near the lake, while areas
farther inland remain hot in the 80s, though not as warm as
Tuesday. Isolated showers and thunderstorms remain possible on
Wednesday afternoon in the general vicinity of the boundary to
our south.

Late this week through early next week:

The surface high pressure builds drifts southward over the
forecast area beginning Thursday. Ridging aloft should keep the
weather dry and mostly sunny. The surface high pressure will
slowly weaken Thursday into early Friday as it sags southward.
Northeast winds and a prominent, though slightly weaker, lake
breeze is forecast Thursday before winds turn southerly for
Friday. There are indications we may get some diurnally driven
or weak shortwaves to kick off some low chances for showers and
storms (10%) Friday or Saturday. The ensembles have us dry for
now, but would not be surprised to add some PoPs back in at some
point. Friday should trend warmer again. Saturday and Sunday
will see another area of surface high pressure drifting south
from near Hudson Bay to Ontario. The tightening pressure
gradient will support another lake breeze on northeast winds
keeping areas near Lake Superior cooler while areas farther
inland will experience continue warm temperatures. The dry and
warm conditions Friday and Saturday and the absence of
widespread rainfall will increase concerns about near-critical
fire weather conditions with low RH values possible.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1232 AM CDT Tue May 26 2026

Mostly clear skies are expected early this morning with winds
being light and variable. There is a 30% chance for areas of
MVFR to IFR fog developing in KDLH, KHIB, and KBRD by sunrise.
Once daytime heating begins, expect fog to dissipate and
conditions to become VFR. Scattered showers and thunderstorms
will potentially be developing in the late afternoon into
evening around KBRD and KHYR along a slow moving cold front.
Farther north, dry air behind the cold front is expected to
inhibit shower and thunderstorm development.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 349 AM CDT Tue May 26 2026

Light winds this morning will gradually strengthen from the
east and northeast through the morning. Wind speeds will
increase to 5 to 12 knots. A few gusts to 15 to 18 knots are
possible. The strongest winds will be found in the southwest arm
of Lake Superior. There is a 5-10% chance of isolated storms
this afternoon, generally south of a line from Two Harbors to
Outer Island to Ontonagon. Occasional cloud-to-water lightning,
locally heavy rain which will reduce visibility to less than 1
mile at times, and small hail up to half-inch diameter. Strong
high pressure over far northern Canada will sag southward into
far northern Ontario Wednesday and Thursday. The pressure
gradient will tighten over western Lake Superior and will create
stronger northeast winds of 5 to 18 knots. The strongest wind
will be in the southwest arm of Lake Superior. Wind gusts will
of 15 to 25 knots are forecast. Conditions may become hazardous
for smaller vessels near the Twin Ports and east of Madeline
Island south to Saxon Harbor. Waves near the Twin Ports and
between Oak Point and Saxon Harbor will build to 2 to 4 feet.
Northeast winds will persist Thursday and may also produce
conditions hazardous to small craft, although the risk is
smaller than Wednesday. Saturday will bring another period of
stronger northeast winds.

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

&&

.FIRE WEATHER...
Issued at 349 AM CDT Tue May 26 2026

Dry, near-critical relative humidity values between 20 and 30
percent are forecast this afternoon from near Walker and
Longville to Ely and Sea Gull Lake. The low humidity values will
be accompanied by east winds of 5 to 10 mph. A nearly
stationary front will slowly sag southward from northern
Minnesota early this morning to a Walker to Duluth to Ontonagon,
MI line by late morning and slightly farther south through the
afternoon. South of this boundary winds will be from the south
at 5 to 10 mph. Winds turn east to northeast on Wednesday and a
prominent lake breeze develops, keeping the lakeside cooler
while dry relative humidity values of 25 to 35 percent are
forecast further inland. Similar conditions are forecast
Thursday before warmer temperatures, lower RH, and southerly
winds return Friday.

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

&&

.CLIMATE...
Issued at 349 AM CDT Tue May 26 2026

Hot, summer-like temperatures today and Friday could produce
temperatures nearing daily record highs at several climate
sites. Below are the sites where forecast high temperatures are
within 3 degrees of their record values.

Record High Temperatures:

Tuesday, May 26:

      Forecast    Record
      --------    ------
KBRD: 89 ........ 92 in 2018
KHIB: 86 ........ 88 in 1978

Friday, May 29:

      Forecast    Record
      --------    ------
KHIB: 86 ........ 88 in 1999 and 2006

&&

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

&&

$$

DISCUSSION...Huyck
AVIATION...Unruh
MARINE...Huyck
FIRE WEATHER...Huyck
CLIMATE...Huyck