157
FXUS63 KDLH 231738
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1238 PM CDT Sat Aug 23 2025

.KEY MESSAGES...

- Cooler, fall-like temperatures are expected this weekend into
  early next week with highs in the 50s and 60s through Monday.

- Patchy frost is possible, especially Monday and Tuesday
  morning, for inland locations away from Lake Superior.

&&

.DISCUSSION...
Issued at 222 AM CDT Sat Aug 23 2025

A noticeable shift to more fall-like weather is underway across
the Northland following the passage of an overnight cold front.
This will set the stage for an unseasonably cool weekend, with
high temperatures struggling to climb out of the upper 50s to
mid-60s, accompanied by overnight lows dipping into the mid to
upper 30s and low 40s. Diurnally unstable with cyclonic flow
aloft associated with an upper-level trough will likely generate
scattered to widespread light rain showers across the area both
today and Sunday. As this cooler air mass settles in and high
pressure begins to build early next week, our attention turns to
the potential for frost. The primary forecast challenge will be
Sunday night into Tuesday morning. While deterministic guidance
from the National Blend of Models (NBM) keeps lows near 40
degrees, this solution appears to have a warm bias, running
warmer than 75% of the probabilistic data and even comprises the
upper whisker in rural areas on Tuesday morning. Consequently,
we expect low temperatures will likely drop into the 30s (even
the upper 20s may be possible for the typical cold spots) for
most locations away from the moderating influence of Lake
Superior. A Frost Advisory may be needed if current trends hold.

Beyond this early week chill, the weather pattern is expected
to become quite benign as a large ridge and an expansive area of
surface high pressure build into the region, leading to an extended
period of dry conditions. The next chance for rain arrives late
in the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1238 PM CDT Sat Aug 23 2025

Widespread VFR to MVFR cloud cover is in place across the
Northland this afternoon along with scattered showers. Showers
will continue through sunset before diminishing, although they
may linger through the night along the International Border.
Ceilings are expected to lower to MVFR during the early morning
hours before lifting again by mid to late morning Sunday. Winds
will remain breezy into tonight before weakening a bit and then
ramping back up after sunrise. Showers will be possible again
by late Sunday morning, but shouldn`t be as numerous or
widespread as today.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 222 AM CDT Sat Aug 23 2025

Northwest winds will be flirting with Small Craft Advisory
gusts (20-25 kts) through late Sunday. Meanwhile, waves along
portions of the South Shore and Outer Apostle Islands will build
to 3 to 5 feet. Some shower activity during the afternoon today
and tomorrow, but tstorms are not expected.

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...Small Craft Advisory until 7 PM CDT Sunday for LSZ121-140>148-
     150.

&&

$$

DISCUSSION...Wolfe
AVIATION...BJH
MARINE...Huyck