192
FXUS63 KDLH 132047
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
347 PM CDT Sun Jul 13 2025

.KEY MESSAGES...

- A few showers or storms are possible along a weak front that
  moves through the area this afternoon and evening. Severe
  storms are not expected.

- Northwesterly winds behind the front will usher another plume
  of Canadian wildfire smoke into the area tonight through
  tomorrow.

- Additional rain and storms are possible Monday night through
  Wednesday as a slow moving cold front moves through the
  region, with cooler temperatures to follow.


&&

.DISCUSSION...
Issued at 124 PM CDT Sun Jul 13 2025

This Afternoon and Tonight:

Increased southwesterly flow has pushed smoke concentrations out
of the area this afternoon, improving visibilities and air
quality across the Northland. This break will be short-lived as
the next round of Canadian wildfire smoke is already entering
northwest Minnesota behind an approaching front. As this front
pushes southward, isolated showers and storms are possible, but
expect coverage to be low. Forcing is rather weak along the
front with a limited cu field south of the Canadian border (per
latest satellite imagery) as the upper level trough axis is
already east of the area. Instability parameters - SBCAPE
around 2000J/kg and bulk shear of 30kts - could be enough to
overcome the poor lapse rates, drier mid levels, and weak mid
level height raises for a few storms to develop this afternoon
and evening. Will cap coverage at 20-25%. Canadian wildfire
smoke will return to the Northland behind the front, reducing
air quality through Monday.

Zonal flow aloft over the area Monday keeps conditions warm,
with highs in the 80s for much of the area. A stronger midlevel
trough begins to cross the Rockies, with a surface low moving
into the Central Plains and an inverted trough extending
northeastward into the Northland. This establishes a low level
convergence zone to our northwest and a focus for showers and
storms Monday, that expand into north central MN during the
afternoon. This inverted trough/surface convergence boundary
shifts over the area Monday night and remains as a series of
waves trip over the boundary, finally clearing northwest WI
Wednesday night. Waves of moderate to heavy rainfall are possible
as moisture transport along the boundary pushes PW values to
near 2 inches Monday night into Tuesday. There is some
uncertainty on where exactly the boundary sets up, being the
focus for training waves of heavy rainfall. Where this does
happen will result in an increased chance of localized flooding,
with 1-2 inches of widespread rainfall expected, and local
amounts of 3-5 inches. There will also be a chance of strong to
severe storms, most likely Tuesday into Tuesday night, as better
forcing aloft arrives and lapse rates improve. Instabilities
increase during the afternoon, with modest bulk shear values.
Limiting factors would be the overall moist profiles and the
possibility of a weak cap around 700mb preventing significant
core growth.

Cooler temperatures arrive behind the front with highs in the
60s to lower 70s for Wednesday through the end of the week.
Lingering rain showers end Thursday morning as surface ridging
builds across the area. Rain chances return for Friday and
Saturday, as some weak shortwaves move through the broad
cyclonic flow aloft.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1220 PM CDT Sun Jul 13 2025

Visibility reductions from Canadian wildfires will improve
through the afternoon, as winds increase from the southwest,
ahead of an approaching cold front. Wind gusts of 18-22kt are
possible.

That cold front will slide through the area late this afternoon
and this evening. A few showers or storms are possible along the
front, but coverage is not great enough to include at any
particular taf site. The cold front this evening may bring
another surge of smoke behind it tonight and some reduced
visibilities once again.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 124 PM CDT Sun Jul 13 2025

Breezy southwest winds along the North Shore and head of the
lake diminish this evening, and gradually turn to the south to
southwest overnight. Speeds increase to 5-7kts Monday with gusts
of 20kts, mainly from Grand Marais and Grand Portage. Winds become
more variable in direction with generally light speeds Monday
night into Tuesday. Isolated storms are possible this afternoon
and evening with additional chances for storms (30-40% chance)
Monday night into Tuesday, increasing to 70-80% during the day
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...Small Craft Advisory until 8 PM CDT this evening for
     LSZ140>146.

&&

$$

DISCUSSION...HA
AVIATION...HA
MARINE...HA