Area Forecast Discussion
Issued by NWS Duluth, MN

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044
FXUS63 KDLH 060839
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
339 AM CDT Sun Jul 6 2025

.KEY MESSAGES...

- Seasonal temperatures much of the week with a brief warm up
  Thursday.

- Showers and storms return Monday into Tuesday. A few of these
  storms could become strong with gusty winds and small hail
  Monday afternoon and evening.

- Additional shower and thunderstorms chances during the latter
  half of this week into Saturday, some of which could also
  become strong to severe at times.

&&

.DISCUSSION...
Issued at 338 AM CDT Sun Jul 6 2025

Today - Tonight:

A largely pleasant day is in store for most of the Northland
today in the wake of yesterday`s cold front as more seasonable
high temperatures in the 70s are expected for most. A lake
breeze today will keep the North Shore, Twin Ports, and portions
of northwest WI cooler with highs in the mid to upper 60s.
Humidity will be noticeably lower today with dewpoints in the
50s for most and then dropping into the 40s for dewpoints with
the lake breeze. Some Canadian wildfire smoke aloft should also
mix down to the surface today into this evening, reducing air
quality and visibility at times. The best potential looks to be
along and north of the Iron Range.

A weak shortwave mid/upper level trough sliding through a zonal
flow pattern later this afternoon into early tonight may produce
some light, stray rain showers/sprinkles (10-20%) for far
northern MN, though dry air near the surface should keep it
mostly as virga. Little to no accumulations expected.

Monday - Tuesday:

A stronger mid/upper-level shortwave trough slides through the
Northern Plains on Monday and through northern MN Monday night
into early Tuesday. Cloud cover increases ahead of this system,
with a tongue of 1.25-1.5" of PWAT values nosing into the
Northland, which should be a catalyst for shower and
thunderstorms in the Northland Monday afternoon into Tuesday.
While most of the rainfall is poised to fall Monday evening into
Monday night, the instability/shear profile Monday afternoon and
evening looks sufficient for a few stronger storms to develop.
0-6km shear around 30-40kt and 800-1400 J/kg of MUCAPE should be
enough to produce some semi-organized storm clusters, with
isolated gusty winds (40-50 mph) and near severe hail
(pennies/nickel size) as the main threats given rather modest
low and mid-level lapse rates, along with brief localized heavy
rain. Strong storm potential wanes with eastward extent, so the
best potential should be across north-central/northeast MN into
the St. Croix River Valley.

Look for high temperatures both days to be in the 70s to lower
80s, and slightly cooler near Lake Superior.

Wednesday - Next Weekend:

We see a brief warming trend for Wednesday into Thursday as a
shortwave ridge aloft moves across the Upper Midwest, which
should push temperatures into widespread 80s away from Lake
Superior on Thursday. Can`t rule out some mid-upper 80s with
heat indices around 90F in north-central MN on Thursday as the
crest of the ridge axis is moving through and the highest
dewpoints (mid/upper 60s) would be present. Some mid-level
shortwave vorticity and a 30 knot low-level jet Wednesday
night/Thursday morning could kick off some showers and storms
in north-central MN, but weak shear and instability should keep
these as non-severe.

More potent moisture advection should then occur later Thursday
into Friday ahead of a strengthening upper-level
shortwave/low as it crosses the southern Canadian Prairies,
bringing PWATs of 1.5-2" into the Upper Midwest once again.
Still some decent spread in timing/intensity/track differences
among global ensembles with this system, so confidence on exact
details on severe thunderstorm and heavy rainfall/flooding
potential remains lower at this time. With that said, early
indications are that the instability/shear parameter space for
Friday/Friday evening could support a severe weather threat
should this system track across our area at the optimal time.
Regardless, expect a return of precipitation chances (50-70%)
late Thursday into early Saturday.

Temperatures moderate behind this late week system, with highs
back to seasonal values in the 70s to around 80 next weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1248 AM CDT Sun Jul 6 2025

A cold front has moved through the Northland with drier air
working into the region in the wake of the front. Some areas
that saw rain yesterday could see some areas of MVFR to IFR fog
during the current overnight, particularly KHYR. However, as the
drier air continues to work in, winds could stay just elevated
enough to prevent more than just isolated fog development.
Outside of this fog potential, VFR conditions are expected for
the remainder of the period with diurnal cumulus developing
today with some Canadian wildfire smoke mainly staying aloft. A
few showers could affect the KINL vicinity later this afternoon
into evening, but drier air near the ground may just evaporate
any rain before it reaches the ground.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 338 AM CDT Sun Jul 6 2025

Dense fog along the western Lake Superior waters has lifted, so
the Dense Fog Advisory was cancelled. Winds turn northeasterly
today at 5-15 kt and gusts to 15-20 kt, becoming strongest
along the South Shore and at the head of the Lake where wave
heights around 2-3 feet develop today. Winds become light and
variable tonight with lower waves before becoming northeasterly
again Monday at 5-10 knots with gusts of 10-15 kt. Chances for
showers and thunderstorms then return late Monday afternoon into
early Tuesday. Additional thunderstorm chances return late this
week for late Thursday into Saturday.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Beach Hazards Statement from 7 AM CDT this morning through
     this evening for MNZ037.
WI...Beach Hazards Statement from 7 AM CDT this morning through
     this evening for WIZ001.
MARINE...None.

&&

$$

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