Tornado Warning 12, NWS Duluth, MN

Area Forecast Discussion
National Weather Service Duluth MN
342 PM CDT Fri Jul 24 2026

.KEY MESSAGES...

- Scattered strong to severe thunderstorms are possible late
  this afternoon and evening. Large hail to golf ball size is
  the main threat, but damaging wind gusts and perhaps a tornado
  can't be ruled out.

- Hot weather with temperatures in the upper 80s and 90s are
  likely this weekend and early next week. A Heat Advisory is in
  effect for Saturday and an Extreme Heat Watch was issued for
  most of the Northland Sunday.

- Another round of showers and storms are forecast Sunday
  afternoon and night. A few strong to severe storms are
  possible.

- Isolated to scattered showers and storms over the next week
  are forecast. Widespread measurable rainfall is not expected,
  although areas that see thunderstorms may pick up half an inch
  to 2 inches of rain.

&&

.DISCUSSION...
Issued at 342 PM CDT Fri Jul 24 2026

Stratus remained in place over much of the Northland this
afternoon in response to a broad area of isentropic ascent ahead
of an approaching shortwave trough. Thunderstorms percolated
along the Canadian border west of Baudette this morning and
recently began to intensify. Will keep an eye on these storms as
the propagate eastward into north-central Minnesota. The
stratus limited temperatures to the upper 60s to middle 70s for
most locations today which likely has negative effect on
instability at the moment. Skies are clearing south of the area
of storms and rapid heating may develop as the clearing moves
into western Itasca and western Koochiching counties.

High-res guidance has been of little use so far today as the
models are under-representing the ongoing convection. They have
been consistent in developing another round of strong
thunderstorms over far northeast North Dakota and northwest
Minnesota between 22Z and 25.00Z and propagating them eastward
into north-central Minnesota. Recent regional radar mosaic
revealed strengthening storms along and north of an outflow
boundary from earlier convection. Southerly low-level flow is
amplified in this area per the latest SPC RAP mesoanalysis.
There is divergence at 850 mb in that area with stronger
southwesterly flow over northwest Ontario and strong convergence
at 700 mb. These factors will continue to support storm
redevelopment through early evening. Hodographs reveal favorable
veering in the 0-6 km layer for storm-scale organization with a
long, straight hodograph above ~4 km, which will support
efficient mass evacuation. Look for embedded supercells
initially with the potential for large hail and perhaps a
tornado this afternoon into early evening. Cold pool
consolidation will lead to upscale growth and a transition to a
hail and wind threat.

We will need to be mindful of training storms and the potential
for excessive rainfall. KMVX storm total precip from 1205Z
until 2007Z reveals a narrow stripe of more than 3 inches of
rain.

Heat and humidity return starting Saturday and will persist
through early next week. We issued a Heat Advisory for Saturday
over most of the Northland and an Extreme Heat Watch for Sunday.
Additional heat headlines may be needed Monday and Tuesday.

In addition to the heat Saturday, there is a risk of a storm or
two breaking through the cap. In the event storms develop, they
will be capable of large hail and damaging wind. As of this
afternoon, the risk of storms is less than 10% for any given
location.

Sunday will bring another potential for showers and storms,
some of which may be severe. An elevated mixed layer is forecast
to advect eastward over the region which will limit storm
potential initially. Strong heating beneath the cap will result
in an area of 3000-4000 J/kg of MUCAPE. There is a small chance
a few storms may break through the cap in the afternoon. The
more likely evolution will be storms developing near a cold
front in southern Manitoba and northeast North Dakota and moving
into north-central and central Minnesota during the evening. If
storms form in the afternoon, very large hail and damaging
winds are possible. With the later round of storms, damaging
winds will be the main threat.

Temperatures cool a bit behind the front Monday. Heat headlines
may be needed once again. For the remainder of next week,
temperatures will be in the 80s and low 90s until Friday.
Additional heat headlines may be needed. There will also be
periodic chances of rain and storms, mainly focused Wednesday
night and beyond.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 106 PM CDT Fri Jul 24 2026

MVFR CIGS will persist this afternoon. DLH and HYR are expected
to see ceilings lower to MVFR early this afternoon. An area of
showers and storms over far northwest Minnesota will propagate
eastward into INL around 20Z. Additional showers and storms are
forecast to develop tonight and will move eastward across
northern Minnesota through 25.09Z. BRD has the lowest chance of
precipitation. In the wake of the showers/storms early Saturday
morning, there will be a period of MVFR ceilings before
conditions improve.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 252 PM CDT Fri Jul 24 2026

Gusty southwest winds linger into tonight. Winds are expected
to gust between 20 and 30 kt through most of tonight. As such,
Small Craft Advisories remain in effect and gradually end
tonight and early Saturday morning. The last segment to end
will be near Grand Marais to Grand Portage, where the gusty
winds may last the longest into Saturday morning.

In addition to strong southwest winds in general, there is a
chance for showers and thunderstorms this evening and overnight,
which may result in gusty and erratic winds and perhaps some
small hail.

Winds will calm down on Saturday, become light and variable
Saturday night, then become light from the northeast on Sunday.
There is another chance of showers and storms Sunday, some of
which may be strong to severe. Wind gusts of 40 to 60 knots and
hail to quarter size is possible.

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

&&

.FIRE WEATHER...
Issued at 252 PM CDT Fri Jul 24 2026

Showers and scattered thunderstorms are forecast generally
north of US-2 tonight. Rainfall amounts of 0.10-0.25 inches are
forecast. Areas affected by stronger storms may see more than an
inch of rain. A few storms may be strong to severe with wind
gusts of 40 to 60 mph. Saturday will be hot. Heat Advisories are
in effect for much of the Northland. Afternoon RH values will
dip to 35-50%. Portions of NW WI where clouds and showers linger
will see higher RH values. Winds will be mainly from the
northwest at 5-10 mph with gusts to 20 mph. There is a 10%
chance of an isolated storm or two Saturday afternoon over
north-central MN. Sunday will be warmer. An Extreme Heat Watch
is in effect where the worst conditions are forecast. Another
round of showers and storms is forecast during the afternoon
through the night. A few of those storms may be strong to
severe. Not as hot on Monday, though Heat Advisories will likely
be needed. Next week will see afternoon RH values in the 35-50%
range each day.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory from 11 AM to 9 PM CDT Saturday for MNZ010-018-
     019-025-026-033>038.
     Extreme Heat Watch from Sunday morning through Sunday evening
     for MNZ018-025-026-033>038.
WI...Heat Advisory from 11 AM to 9 PM CDT Saturday for WIZ001-002-
     006-007.
     Extreme Heat Watch from Sunday morning through Sunday evening
     for WIZ001>003-006>008.
MARINE...Small Craft Advisory until 7 AM CDT Saturday for LSZ121-
     146>148-150.
     Small Craft Advisory until 10 AM CDT Saturday for LSZ140.
     Small Craft Advisory until 4 AM CDT Saturday for LSZ141>145.

&&

DISCUSSION...Huyck
AVIATION...Huyck
MARINE...Huyck
FIRE WEATHER...Huyck

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