Latest Duluth Area Text Forecast Discussion product from NWS:
762
FXUS63 KDLH 232058
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
258 PM CST Sun Nov 23 2025
.KEY MESSAGES...
- Unseasonably warm weather Monday with increasing clouds and
maybe a little rain late-afternoon.
- A wintry system will bring rain starting around Monday evening into
Tuesday, changing to snow Tuesday afternoon and evening and
ending for most places by Wednesday evening. Accumulating snow
and blustery winds are likely for many places.
- Lake-effect snow is expected to increase in northern Iron
County Wednesday and Wednesday night, then taper off going
into Thursday evening. Heavy snow amounts are possible.
- Cold temperatures are expected from Wednesday onward.
- Another impactful winter system may affect the upper Midwest
this weekend, which could cause post-Thanksgiving travel
impacts.
&&
.DISCUSSION...
Issued at 257 PM CST Sun Nov 23 2025
Some warm air advection today is fueling clouds for much of the
region this afternoon. We might see a little clearing up north
tonight into Monday, but otherwise we will probably have at least
some clouds around.
On Monday, we start to see influences from our incoming storm system
from the south. Models continue to back off on the start time of
rain in our region. It is quite possible that we remain completely
dry on Monday and don`t see the initial round of rain arriving from
the south until sometime later Monday night, probably in northwest
Wisconsin. In fact, pretty much all of the synoptic forcing for that
looks like it will be largely confined to Wisconsin, so most of
northeast Minnesota might even stay dry until precipitation starts
associated with the second west-to-east tracking low that will pass
through Tuesday and Wednesday. At this point, it looks like this
second low will essentially overtake the first on Tuesday, tying in
with the deformation rain band and spreading moisture through a
TROWAL westward to the north and northwest quadrants of what will
become one stronger low once they merge.
While models had waffled quite a bit from Friday to Saturday, they
are showing more consistency into today regarding an area of strong
vertical ascent ahead of the upper level low, which will pass
through the region Tuesday afternoon and night. This is what we
are watching for the potential for accumulating snow. There
have been some high QPF amounts in global ensemble members that
I still hesitate at buying into at face value. We should see a
~6 hour period where the strong vertical ascent could produce
some efficient dendrite growth and snowfall rates that could be
in the 0.5 to 1 inch per hour area (maybe even locally higher
briefly). But, the low will be passing through fairly swiftly,
so duration of heavy snow rates will be a limiting factor in
producing very high QPF and thus snowfall amounts. Snow-to-
liquid ratios are also in question as we will be starting with
wet/heavy snow in the evening as cold air advection develops
behind the low`s passage and temperatures start to fall below
freezing. Snow-to-liquid ratios should be pretty low initially,
then gradually increase into the evening and overnight. In the
heart of the heaviest snow during the evening, we should
definitely have saturation through the DGZ and some pretty
efficient dendrite production (i.e. big snowflakes that can
accumulate quickly). But, this isn`t the most efficient-looking
thermal profile I`ve seen, and SLRs will probably be closer to
10-15:1...maybe a smidge higher. Lingering wraparound light snow
into Wednesday morning may approach the "light and fluffy"
consistency, and with wind gusts increasing to around 25-35 mph
and temperatures staying below freezing, some blowing snow may
occur. I`m not as concerned about ptype issues Tuesday afternoon
and evening since most of the precipitation will be moving in
coincidentally around sunset, and a fairly smooth transition
from rain to snow seems likely. Areas around the Brainerd Lakes
are maybe the most uncertain for snowfall amounts relative to
ptype issues. If it stays warm enough with the onset of this
precipitation in the afternoon, there could be a bit more rain
there before it eventually transitions to snow, which could eat
into amounts a bit.
Despite there still being a fair amount of forecast uncertainty,
there are some pieces that appear to be coming together. For
example, most ensembles have a swath of precipitation associated
with this second and overtaking low tracking somewhere through our
CWA. There is even a bit of clustering going on with total QPF
amounts around 0.5 to 0.6" at Duluth and Brainerd per SREF plumes
(though there are still plenty of outliers). This gives a bit of
increasing confidence that this area of precipitation may pass
through the Brainerd Lakes to Duluth and into western Lake Superior
areas. There is now a lot less clustering (and thus higher
uncertainty) up north towards International Falls. There are plenty
of ensemble members that take the main axis of precipitation through
the Iron Range or into northwest Wisconsin, so still plenty of
change that could still happen, but at least we`re starting to see
somewhat of a trend starting to emerge.
For QPF and snow amounts, I mentioned that some ensemble members
have had some high QPF amounts that I am not so sure about. My main
concern is the fairly quick movement of this low Tuesday evening and
night, so while some higher amounts are certainly possible, I`m
leaning towards the mean and favoring totals in the 0.5 to 0.7"
ballpark with locally higher amounts for QPF. Translating this to
snow amounts, given the variable SLRs, most places are likely to see
advisory-level snowfall amounts and several 6"+ totals are certainly
possible if some of those higher ensemble members come out to be
correct.
All of that above was focused on the main synoptic forcing, but we
also have lake-effect to talk about. As snow starts to end Wednesday
morning for most places, the South Shore will "clear up stormy" as
snowfall rates start to ramp up Wednesday. Strong cold air advection
will develop, initially enhancing the synoptic snow along the South
Shore Wednesday, then translating to mainly pure lake-effect going
into Wednesday afternoon and night. Lake-to-850 hPa temperature
differences should be around 15 to 20 degrees celsius, which should
be very favorable for heavy lake-effect snow. The caveat may be wind
direction, which may become slightly more west than north Wednesday
afternoon and evening, which may confine the heaviest bands to
northwest Iron County. But there and then, wind shear should be
pretty minimal and copious over-lake instability could easily result
into some 1-2" per hour snowfall rates. There`s still some variation
among ensemble members for total QPF, but most are over an inch and
with SLRs likely to be >15:1, I think the snow should fall heavy and
accumulate easily. This is the place that I actually lean on the
higher end of QPF from ensemble solutions. Latest NBM probabilities
for 12"+ of snow are ~90% and are around 60-70% for 18"+ of snow.
This, in my opinion, may be a smidge high, but still the potential
is there for significant amounts of lake-effect snow.
Winter Storm Watch Rationale: With confidence increasing on this
upcoming system, we have decided to issue Winter Storm Watches for
much of the region. We are looking at current forecast snowfall
amounts that are a little above and below the usual 6" storm total
threshold for considering a watch. We decided to be generous in
coverage of these for several reasons: 1) This is the first
accumulating snow for much of the region, 2) It is happening during
pre-Thanksgiving holiday travel, 3) Storm track may change a bit,
and we want to have watches out for areas where we are reasonably
confident that the heaviest amounts could fall, and 4) There is
still uncertainty and potential for higher amounts to occur should
some of the higher QPF solutions among ensembles ring true.
Confidence is about 50% for most places, except higher along the
South Shore. It is likely that several areas under a watch may end
up with an advisory and not a warning, but we want to "watch" all of
these areas until we can narrow down places where conditions may
warrant a warning.
There may be a few lingering light snow showers on Thanksgiving and
lingering lake-effect along the South Shore, but by and large, snow
should be tapering off. The main story thereafter is that it`s going
to be cold! Whatever snow falls is going to stick around.
The weather pattern will remain active, and there is potential for a
large winter storm to impact some parts of the upper Midwest going
into the weekend. There may be even more that follow with a
southwest-to-northeast oriented storm track setting up. At this
time, it looks like storm tracks are generally favoring areas
southeast of the Northland, but these tracks could certainly shift.
At the very least, those with travel plans to/from places southeast
of here should keep a close eye on the the forecast.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1143 AM CST Sun Nov 23 2025
Aside from higher broken to overcast ceilings, the weather is
pretty quiet out there. Expect predominantly VFR conditions
through the period. This evening, as warm air advection
continues, there may be a little LLWS at places like HIB/INL and
possibly HYR. This will be just a brief ~3 hour period though,
and if winds remain a little breezy close to the surface, LLWS
could fail to develop. There is a bit of a signal for some fog
just after sunrise Monday with a low-level inversion expected.
Some MVFR visibilities can`t be ruled out at times.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 257 PM CST Sun Nov 23 2025
Winds are expected to shift to southwesterly overnight and
become a bit blustery with gusts up to 20 kt. Localized and
brief gusts to 25 kt can`t be ruled out around the outer Apostle
Islands, but confidence is not high enough to issue a headline
at this time.
Winds briefly decrease on Monday before switching to
northeasterly ahead of a low pressure system Monday night. Winds
are then expected to increase into Tuesday. Widespread gusts to
around 25 to 30 kt. Gales are possible (up to 40% chance) late
Tuesday night through Wednesday night. Gusty winds will decrease
slightly thereafter, but likely remain strong with gusts to 20
to 30 kt through early Friday morning. Small Craft Advisories
are likely to be needed, and Gale Warnings may be needed.
Through this time, rain changing to snow is expected as well.
For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Winter Storm Watch from Tuesday morning through Wednesday
morning for MNZ010-018-025-026-033>036.
Winter Storm Watch from Tuesday afternoon through Wednesday
evening for MNZ011-012-019>021-037.
WI...Winter Storm Watch from Tuesday evening through Wednesday
evening for WIZ001-002.
Winter Storm Watch from Tuesday evening through late Wednesday
night for WIZ003-004.
MARINE...None.
&&
$$
DISCUSSION...JDS
AVIATION...JDS
MARINE...JDS
NWS DLH Office Area Forecast Discussion
