544
FXUS63 KDLH 181141
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
641 AM CDT Fri Sep 18 2026

.KEY MESSAGES...

- Showers will spread across the region today and linger into
  Saturday morning. The heaviest rainfall (30-50% of 1") will be
  south of a line from near Pine River to Sandstone to Hayward
  to near Phillips.

- Dangerous swimming conditions expected for the beaches of the
  Twin Ports at times today through Monday.

- Areas of frost are possible each night from Sunday through
  Wednesday night.

&&

.DISCUSSION...
Issued at 357 AM CDT Fri Sep 18 2026

TODAY AND SATURDAY...

Early this morning surface high pressure was centered over
northern Ontario with developing low pressure over northeast
Colorado. Light rain and a few thunderstorms were observed on
regional radar over eastern South Dakota, southwest Minnesota,
and northwest Iowa. The precipitation was associated with a 700
mb trough and enhanced isentropic ascent ahead of the
developing low pressure system. Areas of fog developed over
portions of northeast Minnesota since about 9 PM. High stratus
streaming northward ahead of the low pressure system is expected
to limit additional cooling. Winds will also gradually increase
through sunrise. The combination of these factors will allow
fog to dissipate.

The rain will gradually spread northward through the day while
combating northerly dry air advection aloft. The dry air
associated with the anticyclonic circulation around the Ontario
high pressure will limit the northward reach of rainfall today.
Forecast rain totals in our area of responsibility haven`t
changed much from yesterday afternoon`s forecast. There is still
40% chance or more of 0.5-1.0 inches of rain south of a line
from near Pine River to Sandstone to Hayward to near Phillips.
Meanwhile the 40% chance of a tenth of an inch of rain wasn`t
much farther north indicating the tight gradient of rainfall
expected. That area was south of a line from near Park Rapids to
near Cromwell to near Glidden to near Woodruff. The distance
between the 40% chance of a tenth of an inch and the 40% chance
of 1 inch of rain are separated by only 40 miles!

Winds over the southwest arm of Lake Superior will turn
northeasterly and strengthen today. The wind direction and
resultant waves will pose a high risk of rip currents for the
beaches of the Twin Ports. A Beach Hazards Statement goes into
effect at 1 PM. Rip current risk will diminish as winds relax
this evening and should no longer be a concern by 1 AM Saturday.
Winds and waves build again on Saturday and the rip current
risk is expected to be high once again.

By 7 AM Saturday the high pressure over Ontario will propagate
east into Quebec while the surface low over the Plains advances
into the Midwest. Rain will taper off during the morning
Saturday except for a small area generally along and south of
WI-70 in northwest Wisconsin.

Temperatures today and Saturday will straddle normal. Highs
will be in the upper 50s to middle to upper 60s.

SUNDAY THROUGH LATE NEXT WEEK...

The upper-level pattern will become less progressive Sunday
through next week. A large area of high pressure will slowly
migrate eastward across the Canadian Prairies and northern
Ontario. Precipitation chances become negligible during the
period. There are a few concerns with that evolution. Several
days of strong northeast winds over western Lake Superior will
keep a risk of rip currents in play for the beaches of the Twin
Ports. Sunday appears to be the day with the highest waves.
Areas of frost are possible each night through Wednesday. Monday
night may be the coldest of the stretch and there are portions
of northeast Minnesota and northwest Wisconsin with a 20% chance
of temperatures less than 32 degrees. As of this morning the
forecast included clouds Sunday night which would limit frost
potential. High temperatures will generally be near normal with
values in the upper 50s to the mid and upper 60s.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 641 AM CDT Fri Sep 18 2026

Light rain showers will gradually spread northward into BRD,
DLH, and HYR today. Ceilings will trend lower at all sites
except INL. Look for MVFR to IFR visibility as rain showers pass
over the afore mentioned terminals. HIB may be far enough north
to experience partial clearing tonight allowing fog to form. A
southeasterly low-level jet is forecast this afternoon and
tonight over HYR and BRD. Wind speeds in the jet will reach
35-40 kt. Surface wind speeds are high enough to preclude a
mention of LLWS, though it may need to be added with later
updates.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 357 AM CDT Fri Sep 18 2026

Winds will become northeasterly early this morning. Wind speeds
and gusts will increase. The strongest winds will be found over
the southwest arm of Lake Superior near the Twin Ports. Gusts
up to 25 knots are possible along portions of the North Shore
from late this morning through this evening. A Small Craft
Advisory is in effect from Grand Marais to Duluth to Port Wing.
Winds and waves relax late tonight and will strengthen again
during the late morning and early afternoon Saturday. Another
Small Craft Advisory may be needed. Northeast winds weaken again
Saturday evening and then increase quickly on Sunday. There is
a 30% chance of a few hours of gales to 35 knots from Silver Bay
to Duluth and over the eastern portions of the Apostle Islands
to Saxon Harbor Sunday. Several more days of diurnal
strengthening and weakening northeast winds are forecast Monday
and Tuesday. Additional headlines will likely be needed.

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

&&

.FIRE WEATHER...
Issued at 357 AM CDT Fri Sep 18 2026

No fire weather concerns. Min RHs through the forecast period
remain above 35% throughout the next 7 days, with daily
temperatures generally in the 60s to low 70s. Rain will spread
in from the south today and depart Saturday morning, delivering
up to 0.75" across our southern tier counties, with a sharp
northern cut-off in totals. Drier conditions and light winds
return for Sunday into early next week.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Beach Hazards Statement from 1 PM CDT this afternoon through
     late tonight for MNZ037.
WI...Beach Hazards Statement from 1 PM CDT this afternoon through
     late tonight for WIZ001.
MARINE...Small Craft Advisory from 10 AM this morning to 10 PM CDT this
     evening for LSZ141>145.

&&

$$

DISCUSSION...Huyck
AVIATION...Huyck
MARINE...Huyck
FIRE WEATHER...Huyck