454
FXUS63 KDLH 300522
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1222 AM CDT Wed Jul 30 2025

.KEY MESSAGES...

- Canadian wildfire smoke spreads south over the Northland
  starting today, with reductions to air quality and visibility.
  Air Quality Alerts are in effect for all of the Northland
  through at least Wednesday evening.

- Seasonable temperatures and drier conditions through at least
  early this weekend.

- Chances for showers and storms return late this weekend into
  early next week.

&&

.DISCUSSION...
Issued at 119 PM CDT Tue Jul 29 2025

Today - Saturday:

Slightly cooler and less humid conditions are in store for today
under northwest flow aloft as surface low pressure to our south
and east continues to track away from the Northland. Expect
high temperatures in the mid 70s to low 80s in the MN side of
the Northland and upper 70s to low/mid 80s in northwest WI, with
dewpoints decreasing as the day progresses, particularly later
this afternoon and evening. There will be diurnal cumulus today
as well as some mid-level clouds coming in, but with better
mid-level cloud coverage this evening through tonight as very
weak shortwave energy moves through the northwest flow. Dry air
in the lower levels of the atmosphere should prevent
precipitation from reaching the ground this evening and tonight,
so the forecast was kept dry with less than 10% precipitation
chances. Low temperatures tonight will be much more pleasant
ranging from the upper 40s to low 50s along and north of the
Iron Range to mid 50s to around 60F south of there.

The primary weather concern today into late this week will be
Canadian wildfire smoke spreading south across the Northland as
northwest flow aloft sits across the region and seasonably
strong surface high pressure. The high pressure has forecast
MSLP of 1024-1028 mb, which is in the 99+ percentile of NAEFS
climatology for this time of year, leaving winds light for much
of the workweek which will limit smoke dispersion. The smoke
will lead to reductions in air quality and visibility. Air
Quality Alerts from the MPCA remain in effect until Wednesday
evening in the MN portion of the Northland, and may need to be
extended later into the week. Air Quality Alerts from the
Wisconsin DNR remain in effect until midday on Thursday in the
northwest WI portion of the Northland. See those alerts for more
details.

As the center of the surface high pressure shifts east/southeast
of the Northland Friday into Saturday, southerly surface winds
should help with mitigating smoke concerns. Temperatures for
this timeframe remain seasonal in the 70s to around 80F along
with rain-free weather.

Late Weekend - Early Next Week:

A pattern shift is poised to return to the Upper Midwest again
Sunday into early next week as dewpoints will rise back up into
the 60s again with the southerly return flow advecting moisture
northward into the region. Temperatures don`t look to be as hot
as what we saw this past weekend, however. Ensemble and
deterministic model guidance during this timeframe does show
periods of returning shower and thunderstorm chances as a few
shortwave troughs move through the region, but timing,
placement, and coverage of the precipitation is still lower
confidence due to the spread amongst model guidance at this
time range. With that said, there doesn`t appear to be any
appreciable signals for strong to severe thunderstorm potential
until at least Tuesday of next week--as is also noted in the
CSU, NSSL, and NCAR machine-learning severe storm probability
guidance--given a general lack of forecast instability for
severe storms in the Northland.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1222 AM CDT Wed Jul 30 2025

High pressure settles in across the Northland leading to an extended
period of quiet weather. Flight restrictions will be driven by
poor visibility at times due to wildfire smoke from Canada.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 1249 AM CDT Tue Jul 29 2025

Winds, including gusts, are expected to be at or less than 15 kts
and waves of around a foot or less through late this week as a
high pressure approaches and moves over western Lake Superior.
The strongest of these winds should be Wednesday afternoon and
evening in the head of the Lake and along the South Shore as
winds blow in out of the northeast. Waves could briefly jump to
1 to 2 feet at the head of the Lake from the funneled winds Wednesday
afternoon and evening. Temperatures will be more seasonable, as
well.

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...Rothstein
AVIATION...Britt
MARINE...Rothstein