190
FXUS63 KDLH 272340
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
640 PM CDT Wed Aug 27 2025

.KEY MESSAGES...

- Scattered showers with isolated non-severe thunderstorms to
  continue this evening, especially in the Arrowhead and north-
  central Wisconsin.

- Patchy frost will be possible on Thursday night into Friday morning,
  most likely in the higher elevations of north-central
  Wisconsin.

- Conditions from Thursday into early next week will be dry and
  overall quiet. The next chance for widespread rain arrives mid
  next week.

&&

.DISCUSSION...
Issued at 349 PM CDT Wed Aug 27 2025

Showers and isolated thunderstorms continue to move across the
Arrowhead this afternoon and evening as a shortwave and cold
front moves northwest to southeast across the region. The cold
front is currently moving south across northwest Ontario, and
should enter the Borderlands early this evening, continuing
south overnight. Precipitation chances will be mainly ahead of
this front, along with gusty southwest winds. Behind the front,
winds veer to north, then northeasterly by Thursday morning. We
have not managed to build much CAPE this afternoon, and we have
some other factors keeping the thunderstorm chances low, and am
not too surprise to see little in the way of lightning this
afternoon. Patchy to areas of fog will be possible tonight in
the wake of the cold front as skies clear and high pressure
begins to build in, especially for areas that have gotten
precipitation today.

Cooler temperatures are expected tomorrow behind that front,
with highs only in the mid 60s to low 70s. CAA from Lake
Superior is expected tomorrow as strong northeast winds develop
following the cold frontal passage. This will likely cool high
temps to the low 60s or even upper 50s for areas immediately
downwind of Lake Superior.

Frost will be possible for parts of the area Thursday night
into Friday morning. The most likely location to see this patchy
frost will be the higher elevations of north-central WI, where
skies will be clear for the longest and winds will be lightest.
Current probability of temps less than 40 degrees in this area
is around 60%. Suspect the straight NBM may be bias corrected
too warm given the trends in the past few weeks, so have pushed
the forecast closer to the 25th percentile for overnight low
temps tonight through Friday night with that ridge of high
pressure and drier air in control of our weather.

As the ridge of high pressure at the surface slides off to the
east through the weekend, some weak shortwaves may pass across
the area on the west side of the main upper low over Quebec.
There are some indications of precipitation in the area on
Friday, but I suspect there will not be enough moisture and we
will be dry instead. There should not be any widespread
precipitation chances Saturday or Sunday due to this, with the
influence of the high pressure lingering and a general lack of
moisture. Temperatures should be near normal through the
weekend.

Our next chance for rain comes in the Tuesday night-Wednesday
time frame, as a strong upper low drops into the Upper Midwest.
Near normal temperatures continue through next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 623 PM CDT Wed Aug 27 2025

Scattered thunderstorms continue in northwest Wisconsin as a
cold front slowly drops southward through the region this
evening, expect only scattered rain showers in northern
Minnesota through this evening. As the better instability pool
in Wisconsin shifts southeastward over the next few hours those
scattered general thunderstorms turn over mainly to rain
showers. Areas of fog are expected to create MVFR to IFR
visibility overnight 08-13Z, with slowly lifting ceilings 12-15Z
tomorrow morning. Expect gusty northeasterly winds for Lake
Superior terminals after 12Z Thursday that linger into tomorrow
evening hours.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 349 PM CDT Wed Aug 27 2025

Breezy southwest winds today will diminish this evening before
a cold front moves across western Lake Superior and causes winds
to veer around to the northeast by Thursday morning. Will be
allowing the Small Craft Advisory currently in effect expire at
4 pm as those winds are decreasing. However, behind the front
northeast winds will increase on Thursday, causing building
waves into the southwest arm of the lake. Will be hoisting Small
Craft Advisories beginning early Thursday morning and
continuing through much of the day. Winds diminish again in the
late afternoon and evening, allowing conditions to improve once
again. Winds diminish for Friday into the weekend with gusts
under 10kts, with waves of 1 foot or less.

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 from 4 AM to 4 PM CDT Thursday for
     LSZ143>146.
     Small Craft Advisory from 4 AM to 10 PM CDT Thursday for
     LSZ147-148-150.

&&

$$

DISCUSSION...LE
AVIATION...NLy
MARINE...LE