551
FXUS63 KDLH 240757
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
257 AM CDT Tue Jun 24 2025

.KEY MESSAGES...

- Rainfall chances return Wednesday and persist into Friday.
  Heavy rainfall possible across inland northern Wisconsin.

- Seasonable temperatures, then warmer this weekend.

- Next round of strong to maybe severe storms is possible
  Saturday and Sunday PMs somewhere in the Upper Midwest.

&&

.DISCUSSION...
Issued at 257 AM CDT Tue Jun 24 2025

High pressure today creates a day of sunny skies and seasonable
temperatures in the 70s, all under no rain or storm chances.
With this high pressure and sunny skies though, very low
relative humidity values are forecast across the Northland this
afternoon ranging from 25 to 35 percent. The recent rainfall and
very light winds today though create very minimal fire weather
concerns in the region.

Easterly winds increase over the Big Lake Wednesday as low
pressure deepens in the Central Plains and high pressure
strengthens over northeast Ontario. Expect onshore flow to help
cool parts of the South Shore and much of far northeast
Minnesota Wednesday.

As that low pressure lifts northward Wednesday daytime, a near-
stationary warm front forms over central Wisconsin. South-
southeasterly moisture advection over the stationary boundary
creates a setup for heavy rainfall potential for inland parts of
northern Wisconsin Wednesday evening to Thursday night. The
main areas of concern for the Northland would be light rainfall
along and north of US Hwy 2 and moderate to heavy rain for the
I-35 corridor of eastern MN and across inland northwest and
north-central Wisconsin. The best forcing occurs over inland
northern Wisconsin Wednesday evening to sunrise Thursday morning
which creates concern for areas of heavy rainfall mainly south
of WI Hwy 77. As the low pressure lifts through eastern MN and
central WI Thursday afternoon, another round of heavier rainfall
may occur into Thursday night. In total, there is a 40-70%
chance of greater than 1 inch of rainfall for south of WI Hwy
77, and even higher totals south of WI Hwy 70 where a 30-50%
chance of greater than 2 inches is present. At this time being
on the northern periphery of rainfall, expect a very tight
gradient in the heaviest of rainfall into Thursday night for
areas closer to the MN Hwy 210 through WI parts of US Hwy 2
corridors. The primary impacts for areas along and south of WI
Hwy 70 are likely to be ponding of water with lower-end (15-25
percent) chances of minor flooding into Friday morning.

Expect cool temperatures areawide on Thursday with the rain
showers, even more notable easterly onshore flow and mostly
cloudy skies.

A return to warmer southwesterly flow and a better setup for
strong to maybe severe weather pattern return for this weekend.
Temperatures look to be warmest Saturday in the upper-80s, but
could reach into the low-90s for northern Minnesota. Medium-
range global guidance points to a couple of shortwaves that may
move through the southern Canadian Plains Saturday and Sunday
which combined with Gulf moisture advection, pre-frontal MUCAPE
ranging well-above 1500 J/kg, and modest shear creates another
environment that points towards strong to maybe severe weather
somewhere in the Upper Midwest...just whether this is the
Northland or not has yet to be noted.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1226 AM CDT Tue Jun 24 2025

VFR conditions prevail this TAF period under light northwest
winds shifting southerly after 12-18Z inland and easterly along
Lake Superior shorelines.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 239 AM CDT Tue Jun 24 2025

Light northwest winds under 10 knots shift southerly this
afternoon while remaining light, and then further shift easterly
overnight Tuesday night. Those easterly winds are very likely to
be strongest in the southwestern arm Wednesday, gusting to 20
knots in the afternoon and may create waves of 1-3 feet.
Thursday is looking to be likely to need some limited coverage
Small Craft Advisories as easterly winds increase in speed with
gusts in the range of 20 to 25 knots currently forecast.

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...NLy
AVIATION...NLy
MARINE...NLy