503
FXUS63 KDLH 122324
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
624 PM CDT Sat Jul 12 2025

.KEY MESSAGES...

- Smoke is expected to persist through Monday with perhaps a
  brief break for some places Sunday afternoon.

- The next best chances for showers and storms is Sunday night
  and again Monday night into Tuesday. Occasional shower/storm
  chances the rest of the week.

- Warm weather with highs in the 80s expected Sunday and Monday
  with cooler weather into next week.

&&

.DISCUSSION...
Issued at 1245 PM CDT Sat Jul 12 2025

Smoke:

Plenty of haze and smoke is expected through the weekend due to
prevailing west/northwest winds today, becoming southwest Sunday.
Visibilities will be variable as smoke coverage varies, but
generally between 3-6 miles and occasionally down to 1-2 miles while
plumes of smoke continue to advect through the region roughly from
west to east. Air quality alerts are in effect through Monday for
all of Minnesota and Wisconsin. Find air quality information through
Minnesota Pollution Control Agency (https:/www.pca.state.mn.us/air-
water-land-climate/air-quality) and Wisconsin DNR
(https:/dnr.wisconsin.gov/topic/AirQuality).

This afternoon and tonight:

Aside from the smoke, we have a post-cold frontal air mass in place
today and an upper-level trough that will be moving off to the
east/northeast into tonight. Aside from a few showers and perhaps a
rogue thunderstorm in the Arrowhead through this afternoon, dry
weather is expected. Low-level flow will become more west/southwest
tonight with warm air advection developing due to broader ridging to
our west. A weak shortwave will pass through tonight, but with dry
air expected, there shouldn`t be any rain with it.

Sunday:

On Sunday, expect warm air advection through the day that will cause
some rather toasty temperatures around the mid 80s pretty much
region wide. Again, a pretty dry airmass, so maybe a few
cumulus clouds developing, but otherwise just a warm summer day.
We might even get a little break from the smoke Sunday
afternoon with southwest winds pushing it away just for a bit.

Sunday night:

A cold front is then expected to pass through Sunday evening, and as
it does, there could be just enough instability present to promote
some scattered showers and storms, mainly in northwest Wisconsin.
Right now, convective parameters look actually semi-decent for a few
stronger storms (up to 1.5 kJ/kg MUCAPE; 0-6 km shear ~40 kt; PWAT
just over an inch), so we`ll have to keep an eye on that, but that
all depends if ingredients come together just right. If there are
any storms, they should be in and out of the region pretty quickly
Sunday night. Lack of synoptic forcing sitting under the right exit
region of a jet aloft (leading to some sinking air) could be an
inhibiting factor. After the front passes, we`ll probably see some
more smoke moving in.

Monday:

We get a bit more zonal flow into Monday with some more warm air
advection at/near the surface. So despite a "cold" front, it`s still
going to be a warm Monday with highs in the 80s.

Monday night into Tuesday:

Into Monday night, it`s looking like we`ll get an upper-level wave
passing through with some fairly strong frontogenesis associated
with a cold front that should pass through going into Tuesday. Some
pretty deep moisture with PWATs >1.5" may be possible along with pre-
frontal southwesterly flow aloft that could promote at least some
training potential of thunderstorms that may develop ahead of the
front Monday night. There`s a lot of model disagreement with other
convective parameters as the strongest (likely elevated) instability
may not be perfectly aligned with better bulk shear. So in terms of
potential for strong to severe storm potential, confidence is pretty
low at this time. But in any case, we may see some storms Monday
night and into Tuesday with cooler air advecting in from the north.

Wednesday through Friday:

Some cooler air is looking to settle in Wednesday into Thursday.
Some places may see highs only reaching the 60s. A slightly wavy
quasi-zonal flow pattern for a few days may keep rain/storm chances
in the forecast at times through the end of the week.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 623 PM CDT Sat Jul 12 2025

Visibility restrictions from the Canadian wildfire smoke is expected
to continue through tomorrow morning. The latest RRFS guidance shows
some relief from the smoke tomorrow afternoon but another cold front
coming through Sunday evening may bring another surge of smoke.
Gusty west winds will taper off after sunset. Winds will slightly
back to the southwest tomorrow and increase in speeds in the
afternoon once again. As the cold front slides through tomorrow
evening we may see some storms develop along the boundary. Lack of
moisture advection keeps the probabilities low a this point in
time.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 152 PM CDT Sat Jul 12 2025

Southwesterly winds are expected tonight through midday Monday.
Winds will strengthen in speed on Sunday, and there is a
~20-30% chance that there could be some gusts up to 25 kt, but
more likely topping out at around 20 to 21 kt Sunday afternoon.
Wind speeds decrease Sunday night and become a bit more variable
in direction with generally light speeds Monday night into
Tuesday. There is a small chance (15-20%) for some non-severe
storms Sunday evening. Additional chances for storms are
expected (30-40% chance) Monday night into Tuesday.

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...JDS
AVIATION...Britt
MARINE...JDS