071
FXUS63 KDLH 122347
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
647 PM CDT Sat Sep 12 2026

.KEY MESSAGES...

- Breezy west to northwest winds continue this afternoon with
  the potential for lake effect rain showers near the
  International Border tonight into early Tuesday morning.

- Patchy frost will be possible Sunday night into early Monday morning
  for portions of northwest WI and the MN Arrowhead.

- Widespread showers with embedded thunderstorms are expected on
  Monday into Monday night. Rainfall amounts of 1" or greater
  are likely (50-60% chance) for areas south of the Iron Range.

&&

.DISCUSSION...
Issued at 150 PM CDT Sat Sep 12 2026

Northwest flow is occurring across the region this afternoon
following a cold frontal passage that occurred earlier today. In
this post-frontal environment, gusty winds have been ongoing and
scattered to broken cloud cover has been occurring as lobes of
vorticity at 500mb propagate through and low-level lapse rates
remain moderately steep. An isolated sprinkle is not out of the
question this afternoon, especially north of the Iron Range.

The strong winds being seen this afternoon are expected to ease
overnight, as high pressure gradually builds in from the west and a
weak, shallow nocturnal inversion develops. One thing of note
overnight will be the potential for lake effect rain showers in the
lee of large inland lakes near the International Border, such as
Lake of the Woods and Rainy Lake. The ongoing northwest winds will
provide CAA to the region into tonight, lowering 850mb temps to
within a degree or two of 0 degC by early Sunday morning. With lake
sfc temps still being in the 60s, hi-res model soundings suggest the
potential for several hundred J/kg of lake induced CAPE to develop
early Sunday morning. In addition, the arrival of a 500mb shortwave
on early Sunday morning will help provide synoptic lift. This
shortwave will aid in the development of lake effect rain showers,
which was included in far northern MN where 850mb temps are
expected to be coldest.

With the exception of lake effect rain showers on Sunday morning
near the border, Sunday is shaping up to be a dry and sunny day
across the CWA. Temperatures will certainly feel much more like
fall, with highs in the upper 50s to mid 60s. Northwest winds remain
breezy on Sunday, albeit a bit lighter than what is being observed
today. On Sunday night, mostly clear to clear skies are expected to
drop temperatures into the 30s across a large portion of the CWA.
Patchy frost will be possible in inland northwest WI and in the MN
Arrowhead. If forecast trends hold, Frost Advisories will likely be
needed.

The fall-like pattern is anticipated to change on Monday, as deep
low pressure propagates into the northern Great Plains and brings
attendant sfc fronts through the CWA. With this weekend`s high
pressure propagating downstream into the lower Great Lakes, this
will allow for southerly flow to advect Gulf moisture north into the
CWA. PWATs of 1-2" are possible, which would be in the 90th
percentile or greater of climatology for the upper air site in
International Falls. At this time, the ECMWF EFI is only showing QPF
in the 60-70th percentile, which does decrease confidence in very
heavy rainfall. The current QPF forecast maintains the NBM solution,
which brings a broad 0.3 to 1.0" across the CWA on Monday into
Monday night. Heaviest rainfall is forecast over northwest
Wisconsin, where there is a Marginal risk for excessive rainfall and
just a sliver of a Slight risk in southern Price County. Severe
weather is unlikely as the better thermodynamic environment remains
south of the area.

High pressure is favored to return following the early week low
pressure system, with a trend of warmer temps for the latter half of
the week. High temps from Tuesday into next weekend are forecast to
be largely in the 60s to low 70s. Additional rain chances arrive
both on Wednesday night into Thursday morning and again on Friday
into Saturday as flow aloft remains relatively zonal, allowing
shortwaves to propagate through the Upper Midwest.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 647 PM CDT Sat Sep 12 2026

Breezy northwest winds will decrease under 10 kt within the next
hour or two. As colder air moves in tonight, there is a ~20%
chance for some light rain showers at INL. Visibility and
ceilings are likely to remain VFR, but brief MVFR ceilings or
visibilities with passing showers can`t be ruled out later
tonight. Elsewhere, expect some clouds to be around tonight, but
VFR ceilings are expected. On Sunday, winds will become a little
blustery from the northwest during the midday to afternoon
hours. Otherwise, VFR conditions with mostly sunny skies.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 150 PM CDT Sat Sep 12 2026

Small Craft Advisories remain in effect today into tonight, dropping
off from west to east starting this evening. West to northwest winds
with gusts of 20 to 30 knots are expected to continue through this
afternoon with highest waves of 3-4 feet occurring in the outer
Apostle Islands. Winds will begin easing overnight into Sunday
as high pressure moves into the area.

Another period of hazardous marine conditions are anticipated to
return on Monday into Tuesday as a strong low pressure system moves
through the region. Additional Small Craft Advisories are very
likely. There is also a 30 to 60 percent chance for gale force wind
gusts from the southwest to west, most likely to occur on Tuesday
morning into early Tuesday afternoon. A Gale Watch may be needed if
trends persist.

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

&&

.FIRE WEATHER...
Issued at 150 PM CDT Sat Sep 12 2026

Strong west to northwest winds continue this afternoon following a
cold front that moved through earlier today. Partly cloudy to
overcast skies are occurring in the wake of this front, with the
potential for an isolated sprinkle this afternoon in far northern
MN. There will be a chance for lake effect rain showers in the lee
of Lake of the Woods and Rainy Lake tonight into Sunday morning,
although precipitation amounts will likely be light. On Sunday,
sunny skies are expected for most locations as high pressure
gradually builds.

These sunny skies will not be persisting long, as widespread showers
and thunderstorms arrive on Monday and linger into Monday night. At
least 0.3" of rain is forecast across the region, with a 50 to 60%
chance for rainfall amounts of 1" or greater for areas south of the
Iron Range and in northwest Wisconsin. In addition to widespread
rain, expect strong southeast winds on Monday, which will shift to
westerly and remain elevated on Tuesday.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 8 PM CDT this evening for LSZ121-
     141>148.
     Small Craft Advisory until 4 AM CDT Sunday for LSZ140-150.

&&

$$

DISCUSSION...Unruh
AVIATION...JDS
MARINE...Unruh
FIRE WEATHER...Unruh