666
FXUS63 KDLH 311839
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
139 PM CDT Thu Jul 31 2025

.KEY MESSAGES...

- Smoke and haze are expected to persist for much of the region
through Saturday. Air Quality Alerts remain in effect.

- Near seasonal temperatures and quiet weather (aside from smoke)
into this weekend.

- Isolated to scattered shower and storm chances increase Sunday
  into next week.

&&

.DISCUSSION...
Issued at 138 PM CDT Thu Jul 31 2025

Skies are mostly clear to partly cloudy this afternoon, at least as
far as clouds go, but there are plenty of hazy skies and smoke in
the air. The flow is northwesterly aloft, which is keeping a steady
stream of smoky air making its way into the Northland from Canadian
wildfires, and high pressure centered over northern Minnesota is
producing plenty of subsidence and light north to northeast winds.
This is all essentially creating a high pressure "pool" of smoky air
that will be very slow to go anywhere over the next couple days.
Minnesota Pollution Control Agency has maintained an Air Quality
Alert through 5 PM Saturday and the Wisconsin DNR has issued an Air
Quality Alert through noon Friday. For more details, visit
https://airquality.wi.gov for Wisconsin or
https://www.pca.state.mn.us/air-water-land-climate/air-quality-and-
health for Minnesota.

High pressure at the surface is expected to very slowly move
east/southeast Friday into Saturday, so aside from the smoke, we can
expect some sunshine, quiet weather, and generally seasonable
temperatures through Saturday. As the surface winds become southerly
on the back side of the high pressure on Saturday, we may start to
see some gradually improving conditions as far as the smoke is
concerned.

The upper level pattern starts to become a bit more wavy going into
Sunday. In addition, PWATs increase to around 1.0" to 1.5". As a
whole, rain chances will be increasing. At this time, thunder
chances look pretty low-end with little instability (<500 J/kg),
marginally favorable low-level lapse rates (5 to 8 C/km) and not
favorable mid-level lapse rates (4-5 C/km). Thunder can`t be
completely ruled out, but it just doesn`t look likely at this time.

A similar trend continues into Monday with continued southerly
advection of moisture, but not-very-organized synoptic forcing or
fronts that appear obvious at this time that could act as a catalyst
for storms. With that said, we`ll see some increasing instability as
a whole (albeit with weak shear), so a growing chance for a few
storms mixed with some scattered areas of showers. A strong storm or
two can`t be ruled out, but there`s a lot of uncertainty at this
time given weak forcing in general.

The rest of the week, it`s looking like a generally active weather
pattern with on-and-off chances for showers and storms as several
upper level waves may pass through with periodic episodes of
southerly warm air and moisture advection. There is nothing jumping
out as particularly high concern or impact, but there could be
some storms here and there across the region. At the very least,
perhaps predominantly southerly flow could lead to less smoke
in the air.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1244 PM CDT Thu Jul 31 2025

High pressure will keep the weather quiet through the period.
However, visibility concerns are the main hazard of note, and
MVFR visibilities are generally expected through the period as
waves of smoke and haze essentially spiral around the region.
While there could be some temporary VFR visibilities, current
regional observations are generally MVFR and near-surface smoke
in the models are not expected to change much. There may be
potential for a bit of fog tonight at some terminals as well, so
some locally lower visibilities are possible with smog.
Probabilities for visibilities less than 1 mile are less than 10
percent at this time. Light and variable winds are expected
through the period.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 138 PM CDT Thu Jul 31 2025

High pressure is expected to keep winds light and variable tonight,
then becoming southwesterly Friday through Sunday. While most places
will see gusts topping out around or just above 10 kt, the Outer
Apostle Island and areas around Grand Marais to Grand Portage may
see some higher gusts at times. Up to or just above 15 kt in these
areas Friday afternoon and possibly some gusts approaching 20-25 kt
around Grand Portage Saturday afternoon, which could be hazardous
for small craft. Wave heights generally around a foot or less
through the next few days, except 1 to 3 ft from Grand Marais to
Grand Portage, especially Friday and Saturday afternoons. Quiet
weather except for some lowered visibilities to 2 SM at times due to
smoke in the air from Canadian wildfires.

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...None.

&&

$$

DISCUSSION...JDS
AVIATION...JDS
MARINE...JDS