093
FXUS63 KDLH 221121
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
621 AM CDT Tue Sep 22 2026

.KEY MESSAGES...

- Widespread frost this morning away from Lake Superior with
  some locations falling to freezing or just below. Another
  round of frost expected Wednesday morning, but not as
  widespread.

- Persistent northeasterly winds will keep the threat for rip
  currents in place at Twin Port beaches today and may linger
  into Wednesday as well.

- Precipitation chances return late Wednesday into Thursday
  with the potential for scattered light showers.

&&

.DISCUSSION...
Issued at 241 AM CDT Tue Sep 22 2026

Early this morning, widespread frost is occurring across much
of the Northland away from Lake Superior, as clear skies and
light winds have allowed temperatures to drop into the low 30s
and even a few upper 20s as of 2 AM. A Frost Advisory remains in
effect until 8 AM. Stratus has formed in the upslope flow off
Lake Superior, so far affecting mainly southern Lake and east-
central St. Louis counties. This area of stratus is slowly
expanding, and where it spreads, will stall the radiational
cooling. Otherwise, we are seeing warmer temperatures near both
Lake Superior and some of our inland lakes. After the chilly
start this morning, we should be able to burn off the stratus
fairly early, and then we should see plenty of sunshine for the
rest of the day. High temperatures should rise into the upper
50s near the lake to the low to mid 60s further inland. Easterly
winds will become gusty this afternoon, particularly near Lake
Superior where gusts of 15 to 25 mph are expected.

Tonight will not be as cool as this morning- the ridge of high
pressure will slide east during the day today, allowing return
flow to set up tonight. We are still expecting overnight lows in
the mid 30s to low 40s, leading to another threat of frost,
mainly for inland areas. During the day on Wednesday Southerly
return flow will strengthen on the backside of the departing
high pressure system, allowing afternoon temperatures to climb
into the mid to upper 60s across the region, though we can still
expect upper 50s along the North Shore. Clouds will gradually
increase through the day ahead of an approaching upper level
trough. Winds will shift to the southeast and become a bit
breezier by the afternoon.

Precipitation chances finally return to the area Wednesday
night into Thursday as a potent shortwave moves across the area
from the southwest. Showers will spread from west to east across
the Northland, mainly during the overnight hours, and continue
through Thursday. The atmosphere remains quite dry in the lower
levels, which may limit overall rainfall amounts, but a wetting
rain of at least a tenth of an inch is possible, mainly for
northern Minnesota. By Thursday night, the shower activity will
exit, leaving us with mostly cloudy skies overnight.

Friday we will still be in that southerly return flow, which
should help boost our temperatures into the 60s to near 70
nearly everywhere. We will likely still be under mostly cloudy
skies, but no rain is currently expected.

Looking ahead to the upcoming weekend, temperatures will remain
in the near to above normal category, with upper level ridging
in place over the region. Highs by Sunday and Monday should once
again reach the mid 60s to lower 70s, with the warmest
temperatures across northwest Wisconsin. The forecast does
remain a bit unsettled as additional weak disturbances move
across the region. This will result in off and on chances for
precipitation Saturday through Monday, though no significant
widespread heavy rain or severe weather is anticipated at this
time.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 621 AM CDT Tue Sep 22 2026

Fog with some stratus is affecting several terminals this
morning, with KHIB in LIFR conditions as of issuance time.
Expect gradual improvement through 14z, when they should return
to VFR. KBRD and KDLH have some stratus and fog at some nearby
sites, but these have stayed away so far this morning. Have
included a tempo group for an hour or two to account for these
conditions. Once this morning stratus and fog clears, VFR
conditions are expected through at least 03z tonight. Winds will
be easterly at generally 10kts or less. We are seeing some
indications of stratus and fog developing once again after 08z
tonight, and have included some IFR/MVFR conditions at the sites
most likely to be affected, KDLH and KHIB.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 319 AM CDT Tue Sep 22 2026

High pressure centered over eastern Ontario will maintain
east/northeast winds over Lake Superior today and tomorrow. The
strongest winds will be in the western arm and along the South
Shore both days, where we expect sustained winds of 15 to 20
knots with gusts approaching 25 knots. A Small Craft Advisory
has been issued for several hours this afternoon and early
evening for these areas. Another round of hazardous conditions
may develop again tomorrow, but for a shorter time frame and for
a smaller area. Winds veer to the east to southeast Wednesday
afternoon.

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

&&

.FIRE WEATHER...
Issued at 241 AM CDT Tue Sep 22 2026

Minimum relative humidity values will drop into the 35 to 45
percent range for the Wisconsin Pine Barrens, while remaining
above 45 percent for the rest of northwest Wisconsin and all of
northeast Minnesota. Easterly winds will gust to around 15 to 20
mph near Lake Superior, with lighter winds expected inland.
Wednesday will see slightly higher humidity values. Rain chances
return to the area Wednesday night into Thursday, though
widespread significant wetting rains are not expected for most
of the area.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Frost Advisory until 8 AM CDT this morning for MNZ010>012-018-
     019-025-026-034>038.
     Beach Hazards Statement through this evening for MNZ037.
WI...Frost Advisory until 8 AM CDT this morning for WIZ001>004-
     006>009.
     Beach Hazards Statement through this evening for WIZ001.
MARINE...Small Craft Advisory from 2 PM this afternoon to 10 PM CDT
     this evening for LSZ143>146-148-150.

&&

$$

DISCUSSION...LE
AVIATION...LE
MARINE...LE
FIRE WEATHER...LE