014
FXUS63 KDLH 200801
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
301 AM CDT Wed Aug 20 2025

.KEY MESSAGES...

- Patchy dense fog this morning.

- Sunny and warm weather today and Thursday

- A slow-moving cold front crosses late Thursday through Friday
  and will bring a chance for showers and storms. A few storms
  may be strong to severe.

- Behind the front expect much cooler temperatures for the
  weekend with highs in the 60s and lows in the 40s.

&&

.DISCUSSION...
Issued at 257 AM CDT Wed Aug 20 2025

Patchy dense fog is the main concern early this morning, but it will
gradually burn off, leading to a sunny and pleasant Wednesday. It
is quite transient and therefore have only covered any problem
areas with SPS`s which seems like a good call given the oscillatory
nature of the phenomena.

The quiet weather will be short-lived, as warmer air builds in for
Thursday with highs in the low to mid 80s. A slow-moving cold front
approaching late in the day will bring the potential for showers
and thunderstorms. While a few storms could become strong to severe
with hail and wind, the overall severe threat is marginal as the
storms arrive in Koochiching County around sunset losing diurnal
heating. Initially shear and CAPE are sufficient for strong to
severe storms, but EHI values quickly fade after sunset reducing
the threat. There may be a little LLJ enhancement overnight to
compensate for the lack of instability. The Storm Prediction Center
has maintained a Marginal Risk (level 1 of 5) for portions of
our area to account for this conditional threat for both
Thursday and Friday. One thing to keep an eye on is the
potential for heavy rainfall with PWATS near 2 inches and a slow
moving cold front with upper level flow parallel to the front.
On a positive note, the MPCA says that the Canadian wildfires
have diminished in intensity due to recent rainfall, and
therefore there should be significantly less smoke and better
air quality following the Thursday/Friday cold front relative to
the rest of this summers cold fronts.

A significant pattern change arrives for the weekend as the front
ushers in a much cooler, fall-like air mass with breezy northwest
winds. Highs will drop into the 60s and low 70s. An upper-level
low will keep a chance for scattered showers in the forecast from
Friday night through Sunday. Some lake-enhanced rain showers will
also be possible, especially along the South Shore, as the cold
air passes over the relatively warm waters of Lake Superior. This
cooler pattern will persist into Monday before temperatures begin
to moderate by Tuesday.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1234 AM CDT Wed Aug 20 2025

MVFR stratus is trying to break up...any clearing skies and
calm to very light winds tonight should result in radiational
fog/low stratus tonight through early/mid Wednesday morning.
There is a thin band of advection fog off of Lake Superior that
is affecting the I-35 corridor as of 0530Z. Models show a
widespread signal for IFR to LIFR conditions in fog tonight
across the region. Expect this fog to dissipate and low stratus
to scatter out into Wednesday morning, with MVFR ceilings
hanging around longest at KHYR. VFR conditions return late
Wednesday morning after fog and low stratus dissipate.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 257 AM CDT Wed Aug 20 2025

Light and variable winds through tonight with high pressure
settling in. Winds will trend a bit breezier Thursday night into
Friday with southwest winds becoming northwest as a cold front
passes through. Scattered non-severe showers and storms will be
possible Thursday night. Wind gusts are expected to hover
around 15 kt Thursday night into Friday. NW wind gusts to 20-25
kt are possible going into Saturday for most nearshore zones as
more cooler air moves in from the north.

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...None.

&&

$$

DISCUSSION...Wolfe
AVIATION...Wolfe
MARINE...Wolfe