841
FXUS63 KDLH 051914
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
214 PM CDT Sun Oct 5 2025

.KEY MESSAGES...

- Warm and windy today with scattered showers and isolated, non-severe
  storms. Elevated fire weather conditions persist until early
  evening.

- Cooler temperatures arrive Monday with frost possible Monday
  night and likely Tuesday night. Widespread below-freezing
  temperatures are also possible Tuesday night.

- Slightly warmer temperatures with mostly dry weather late this
  week into next weekend. There are some low-end rain chances
  Thursday into Thursday night and again late this weekend.

&&

.DISCUSSION...
Issued at 213 PM CDT Sun Oct 5 2025

Today - Tonight:

A strong surface low moving across northwest and far north-central
Minnesota into northwestern Ontario has an attendant cold front
draped from northwest Minnesota southwestward into the Central
Plains as of early this afternoon. A strong pressure gradient
associated with this low pressure and cold front will keep very
gusty south to southwest winds going across the Northland the
rest of today at 15-25 mph with gusts of 30-40 mph. Some of the
gusts may approach 45 mph at times, but widespread 45+ mph winds
aren`t expected to occur, so no Wind Advisories have been
issued. Ahead of the front, high temperatures top out in the mid
70s to around 80F this afternoon with minimum relative
humidities (RH) down to as low as 35-40%. The combination of
strong winds, fairly low RH, and drying fuels will keep elevated
fire weather conditions going through the rest of the
afternoon. Winds shift quickly to westerly behind the cold front
later this afternoon and northwest this evening as the front
moves east through the area, with gusts gradually weakening this
evening into tonight. We will need to watch for some stronger
winds/gusts to 30-40 mph lingering a bit longer into tonight
along portions of the North Shore behind the cold front due to
strong cold air advection in northwest winds accelerating some
downslope winds. This cold advection will bring in much cooler
low temperatures in the upper 30s to mid 40s tonight across the
Northland.

As for precipitation: Ahead of the cold front early this afternoon,
some narrow lines of showers are located in the PWAT/moisture
axis across the Minnesota Arrowhead into northwest Wisconsin.
These pre-frontal showers will continue to shift east through the
rest of this afternoon and evening, with coverage being highest
in northwest Wisconsin. Also expect some isolated showers to
develop along the cold front later this afternoon and evening
as the front moves east through the area. The pre-frontal
showers should also be accompanied by some non-severe
thunderstorms this afternoon and evening, again with the best
coverage in northwest Wisconsin. While effective bulk shear is
50-60 kt, limited instability (MLCAPE of 100-400 J/kg) should
keep storms from becoming organized. However, given the strong
non-thunderstorm winds already in place, the showers and storms
could occasionally mix down higher wind gusts to 50 mph through
this evening. Rainfall amounts should remain fairly limited
with most locations seeing less than 0.10", but portions of
north-central Wisconsin could see localized amounts of 0.3- 0.7"
given the better coverage of showers and storms. Precipitation
ends for most of the Northland early overnight, though a few
spotty showers could move into the International Border tonight
into the first half of Monday morning associated with some mid-
level vorticity and upper-level divergence.

Monday - Tuesday Night:

A more fall-like and drier pattern sets up for the early portion of
this week as surface high pressure`s influence takes over the
region. High temperatures will be near normal in the mid-50s to mid-
60s both days, though overnight low temperatures will be dipping
into the 30s both Monday and Tuesday night, leading to frost
concerns for inland areas away from Lake Superior. Currently, it
looks more like areas of frost on Monday night and widespread frost
for Tuesday night. There is also a decent potential for a fairly
widespread freeze Tuesday night in the wake of a passing dry cold
front with probabilities of below-freezing low temperatures reaching
40-80% for areas not immediately near Lake Superior.

Wednesday - Early Next Week:

Shortwave ridging moves into the Upper Midwest midweek and generally
remains over the area in a more broad fashion into next weekend,
keeping high temperatures about 5-15F above normal (60s to around
70F), with even some low 70s next weekend. There may be an embedded
shortwave trough moving through the ridge late week that could bring
some very light rain chances (10-30% chance). Otherwise, we remain
rain-free until next Saturday night/Sunday at the earliest,
with mid-range ensemble guidance hinting at a better potential
for rainfall early next week with another shortwave trough and
associated surface cold front that could push temperatures
cooler behind the front once again.

Given the general dry conditions and lack of rain this week into
next weekend, we will need to watch for any days with overlapping
low humidity and windier conditions for continued fire weather
concerns.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1250 PM CDT Sun Oct 5 2025

Gusty SSW to SW winds from 25 to 35 kt, occasionally
approaching 40 kt, continue this afternoon with winds sharply
shifting west then northwest behind a west to east moving cold
front later this afternoon and evening. Winds stay gusty this
evening into early overnight, but wind gust intensity will be
gradually weakening throughout that timeframe. Westerly winds
with gusts of 15-20 kt set up for daytime Monday.

Showers and possibly a few thunderstorms persist mainly ahead of
the front, but some late afternoon/evening isolated shower
development is possible along the front as well. Best
thunderstorm potential (isolated) will be in northwest Wisconsin
at HYR, but remains around 30% chance, so has been highlighted
by a PROB30 group. MVFR ceilings are fairly high confidence
behind the front at INL late this afternoon and evening, and
can`t rule out some post-front rain showers there as well later
this afternoon and early evening. There is also a 10-20% chance
for a stray shower near INL tonight into early Monday morning,
but the potential is too low to include in the TAF with this
update.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 213 PM CDT Sun Oct 5 2025

Very gusty southwest winds have developed today, with most of
the western Lake Superior nearshore waters in a Gale Warning
until mid-evening. Winds will be quickly turning westerly to
northwesterly this evening into tonight behind a passing cold
front. Scattered showers and perhaps an embedded storm or two is
possible the remainder of the afternoon into early evening. No
severe storms are expected. Gusty winds and high wave heights
will continue into tonight. Additionally, Gale Warnings from
Taconite Harbor to Grand Portage were extended into tonight due
to a signal for enhancement of downslope winds with gusts up to
40 kt behind the cold front starting late this evening. The Gale
Warnings will need to be followed up by Small Craft Advisories
into tonight, as well. Winds are expected to remain a little
lighter at Sand Island to Bayfield to Chequamegon Bay to Saxon
Harbor, where Small Craft Advisories remain in effect into
tonight. There is still a small chance that some brief wind
gusts to 35 kt could be possible through the rest of this
afternoon around Saxon Harbor.

Winds back to southwesterly on Monday with gusts of 10-20 kt,
strongest near Grand Portage. Winds turn more westerly on Monday
night into midday Tuesday with gusts of 15 kt to locally 25 kt,
strongest near Grand Marais to Grand Portage, which could create
hazardous conditions for smaller vessels. Winds weaken and veer
northwesterly late Tuesday behind a dry cold front passage.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 4 AM CDT Monday for LSZ121-147-148.
     Gale Warning until 4 AM CDT Monday for LSZ140-141.
     Gale Warning until 10 PM CDT this evening for LSZ142>146-150.

&&

$$

DISCUSSION...Rothstein
AVIATION...Rothstein
MARINE...Rothstein