078
FXUS63 KDLH 091135
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
535 AM CST Sun Nov 9 2025

.KEY MESSAGES...

- Moderate to heavy lake effect snow is expected today through tonight
  in the higher elevations of Iron and Ashland Counties with an
  additional 3 to 8 inches of snow possible. A Winter Weather
  Advisory remains in effect until 6 AM Monday.

- Outside of the South Shore lake effect snow belt in Iron and Ashland
  Counties, light snow showers will be possible today into
  tonight with accumulations expected to be under an inch.

- A quieter pattern settles over the region this upcoming week
  with temperatures becoming unseasonably warm.

&&

.DISCUSSION...
Issued at 416 AM CST Sun Nov 9 2025

Conditions early this morning across the Northland have been winter-
like as a positively-tilted shortwave trough propagates south into
the Upper Midwest. This shortwave trough is being ejected from upper-
level low pressure located over Hudson Bay, which is associated with
a polar airmass centered around northern Ontario and Hudson Bay.
Northerly winds providing cold air advection have resulted in
unseasonably cold temperatures this morning, with low temps on track
to be in the teens across most of the CWA. Aloft, 850mb temps will
be similarly chilly with guidance showing values around -13 to -15
degC as this polar airmass advects into the area later this morning.

The main story in the near term forecast is moderate to heavy lake
effect snow expected to occur today through tonight along portions
of the South Shore, aided by the synoptic lift provided from the
shortwave propagating through. The aforementioned 850mb temps of
-13 to -15 degC will be moving over a relatively toasty Lake
Superior with latest observations revealing a sfc water temp of
around 7 degC. This delta-T of around 20 degrees will result in lake
induced CAPE as high as 1000 J/kg later this morning into the
afternoon. Expanding beyond just 850mb temps, hi-res model soundings
also reveal steep low-level lapse rates increasing the depth of lake
induced convection up to around 15,000 ft. These very favorable
thermodynamic conditions, combined with the expected northerly winds
will likely result in decent snow accumulations for Iron County and
eastern portions of Ashland County.

Highest lake effect snow accumulations are expected to be in the
higher terrain of northern Iron County, where orographic enhancement
will help to further amplify snow totals. Additional snowfall today
through tonight will be around 3 to 8 inches in the Penokee Range,
with lesser amounts away from the higher terrain. Snowfall rates
late this morning into the afternoon will potentially exceed 1" per
hour at times (30% chance), leading to greatly reduced visibility
and slippery road conditions. A Winter Weather Advisory remains in
effect for Iron and Ashland Counties until 6 AM Monday morning.

Outside of the South Shore lake effect snow belt, light snow showers
and flurries are likely today through tonight as the shortwave
provides weak synoptic lift and low-level moisture remains
marginally favorable. Accumulations outside of the lake effect snow
belts will very likely remain below an inch with a 90+% chance for
<1" of total snowfall. Expect both flurries and lake effect snow to
come to an end across the CWA on Monday as the shortwave propagates
downstream into the mid-Mississippi River valley and drier air moves
in.

Once snow comes to an end on Monday, a fairly quiet pattern is
likely to settle over the CWA for this upcoming week as an upper
level ridge gradually slides from the West Coast into the central
CONUS. Temperatures will begin a warming trend on Tuesday, with high
temps increasing into the mid 30s to mid 40s. By Friday, when the
ridge axis is forecast to be located over the Upper Midwest, high
temps will likely be in the mid 40s to low 50s for most of the CWA.
Precip chances this upcoming workweek will be fairly minimal,
outside of a 20-25% chance for light snow showers Monday night into
Tuesday morning with little to no accumulation. Additional
chances for precip potentially arrive next weekend. Overall,
while this weekend was a taste of winter, conditions later this
week will be a reminder that fall isn`t quite ready to leave
yet.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 535 AM CST Sun Nov 9 2025

Light snow showers are expected this morning into the afternoon,
with a band of locally heavier snow showers currently moving south
towards KDLH early this morning. Visibility will largely be VFR,
except for MVFR to IFR visibility occurring in association with
the heavier snow showers. Areas of MVFR cigs will continue this
morning into the early afternoon, trending towards VFR this
evening across the region. Expect gusty northwest winds today,
easing this evening into tonight. Early tomorrow morning, MVFR
cigs will be possible in KINL and KHIB.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 416 AM CST Sun Nov 9 2025

North to northwest winds will increase today to 10 to 20 knots with
gusts of 20 to 30 knots at times. These winds will lead to waves of
2 to 5 feet along the South Shore, including the northern half of
the Apostle Islands. Small Craft Advisories remain in effect through
tonight with winds diminishing on early Monday morning. Lake-effect
snow showers along the South Shore may lead to reduced visibilities
today, especially near Saxon Harbor. Tuesday will see winds become
southwesterly at 5 to 15 knots with gusts to 20 to 25 knots, with
Small Craft Advisories likely needed into at least Wednesday. Winds
Wednesday will be more westerly and stronger, with a 10-30% chance
for gales during this time.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...Winter Weather Advisory until 6 AM CST Monday for WIZ003-004.
MARINE...Small Craft Advisory until 6 AM CST Monday for LSZ121-140>148-
     150.

&&

$$

DISCUSSION...Unruh
AVIATION...Unruh
MARINE...Unruh