Duluth, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

185
FXUS63 KDLH 200540
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1240 AM CDT Thu Aug 20 2026

.KEY MESSAGES...

- Showers and thunderstorms arrive on Thursday, with a few severe
  storms possible in portions of eastern MN and northwest WI on
  Thursday afternoon and evening. The primary hazard is large
  hail up to 1.5 inch in diameter.

- Scattered showers on Friday afternoon and evening in far
  northern Minnesota.

- Nice weekend gives way to an additional round of strong
  thunderstorms possible Monday PM in north-central Minnesota
  and again Tuesday for much of the region.

&&

.DISCUSSION...
Issued at 150 PM CDT Wed Aug 19 2026

For the rest of the day, expect quiet, dry, and pleasant conditions
across the Northland with seasonal temperatures in the mid to upper
70s. A shortwave will move into the area tonight, bringing
increasing cloud cover west to east tonight. The minimum
temperatures tonight for the Arrowhead and inland northwest
Wisconsin remain expected to be on the chilly side dipping
towards 40 F again...further warmer in the north-central
Minnesota counties though into the 50s.

A warm front lifts through the Upper Midwest late tonight into
Thursday morning and brings about increasing rain shower
chances will early Thursday morning. Isolated general
thunderstorms develop Thursday daytime hour, first in the
Brainerd Lakes area. By Thursday late afternoon, sufficient
bulk shear approaching 50 knots and 1000 to 1500 J/kg of CAPE
within an progged 1.5 to 1.7 inches of precipitable water favor
a few severe thunderstorms first possible in the late Thursday
afternoon hours, but mainly during the evening hours, lasting
into the early overnight hours. Large hail to 1.5 inches in
diameter is the most likely hazard, with damaging wind gusts
being the secondary hazard. The area of most potential is south
of the Iron Range towards the Twin Ports in the early evening
and then areas further southward along the Interstate 35 and US
Hwy 53 corridors in the mid to late evening hours. Localized
rainfall up to 1.5 inches is possible from the strongest
thunderstorms late Thursday evening, but most areas are more
likely to receive 0.25 to 0.5 inches. While the most favored
timing window for severe weather Thursday is 4-9 PM strong
thunderstorms past 9PM to Midnight cannot be ruled out.

A cold front will drop through the area late Thursday night into
Friday morning and bring a return to northwest flow across our
region. A weak pool of instability will arrive by Friday
afternoon and combine with ongoing daytime showers to produce
some general thunderstorms, primarily focused from the Minnesota
Borderlands into the Minnesota Arrowhead region.

Behind the cold front, high pressure will build into the Northland
and provide a very nice and pleasant weekend. Abundant sunshine and
comfortable temperatures in the 70s are expected for both Saturday
and Sunday. The progressive pattern continues into early next week
as the next round of more widespread thunderstorms is forecast for
Monday afternoon and evening. Strong thunderstorms are again
possible Monday afternoon and evening for north-central
Minnesota. For Tuesday a primed environment may have finally
setup over the Northland for another round of strong to
potentially severe weather chances.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1240 AM CDT Thu Aug 20 2026

Showers with isolated thunderstorms currently located in western
Minnesota will move east into the area early this morning as low
pressure moves into the Upper Midwest. Visibility and cigs are
largely expected to be VFR as this morning convection moves through,
although periods of MVFR visibility will be possible under
thunderstorms. There will likely be a brief lull between this
morning convection and additional development occurring this
afternoon. A few storms may become strong to severe this
afternoon and evening, especially in northwest WI, with large
hail and damaging winds being potential hazards. As
precipitation comes to an end tonight, patchy MVFR to IFR fog
will potentially develop.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 138 PM CDT Wed Aug 19 2026

Southwest winds around 10 to 15 knots will continue across the
far North Shore near Grand Portage. A weather system will
approach tonight, bringing chances for rain showers and
thunderstorms Thursday into Thursday night. A few strong storms
capable of producing small hail are possible Thursday afternoon
and evening for the Twin Ports into the South Shore. Winds will
become west to northwesterly by the weekend behind a cold front.

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

&&

.FIRE WEATHER...
Issued at 142 PM CDT Wed Aug 19 2026

Dry conditions will persist for the rest of the day with minimum
relative humidity values dropping as low as 25 percent, especially
over northwest Wisconsin. However, west to northwest winds being
limited to around 5 to 10 mph will keep the overall fire
weather threat minimal. A wetting rain is possible for many
areas Thursday into Thursday night as showers and thunderstorms
cross the region. Thursday evening a few severe thunderstorms
are possible for the Brainerd Lakes to Twin Ports and
southeastward across much of northwest Wisconsin. Additional
shower chances are expected Friday for the region, but wetting
rainfall is not expected; a few general thunderstorms are
possible Friday in far northern Minnesota. A wind shift from
south to north will occur Thursday night into Friday behind a
passing cold front.

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