635
FXUS63 KDLH 291130
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
630 AM CDT Sun Jun 29 2025

.KEY MESSAGES...

- Isolated strong to severe storms are possible mainly in
  northwest Wisconsin this afternoon and evening.

- Lingering non-severe showers and thunderstorms on Monday.

- Mainly quiet weather from Tuesday onward.

&&

.DISCUSSION...
Issued at 332 AM CDT Sun Jun 29 2025

A line of thunderstorms is moving into north-central Wisconsin
and the UP this morning with lingering stratiform rain and a
weak MCV behind it. This should all exit the region within a few
hours. Behind all this, the air should be pretty stable, and
thus PoPs have been trimmed for the morning. We should end up
with some partial sunshine for the mid-to-late morning hours
with pretty quiet weather overall.

The main focus for some thunderstorm development this afternoon
will be northwest Wisconsin as a weak upper level trough swings
through along with a weak cold front. Convective parameters are
looking only marginally suggestive of severe weather potential.
We should have some good instability developing (a couple
thousand J/kg or so), but wind shear is looking like it`ll
generally be below 30 kt through the afternoon. We may still end
up with a few quick storms capable of large hail and damaging
winds with low-end severe criteria (e.g. quarter size hail or
so, and ~60 mph winds). They will probably be rather unorganized
and with severe threats being pretty short lived. We`ll still be
hanging on to 90th percentile PWATs around 1.5", but without
much broad coverage of storms, flooding threats look pretty
minimal (~5% chance). SPC has a marginal risk for severe weather
covering northwest Wisconsin, along with a marginal risk for
excessive rain from WPC. These outlooks are consistent with what
we are expecting for impacts, which should be isolated.

There is a somewhat conditional threat for fog, and perhaps some
dense fog, particularly over northwest Wisconsin tonight. The
more rain that falls during the day, the more low-level moisture
will be available for fog development. But even absent of that,
winds should lighten up and there should be some partially clear
skies, so that gives about a 50% chance for fog and some locally
dense fog.

On Monday, an upper level trough is still expected to pass
through, and with some low-end favorable instability (up to 1
kJ/kg MUCAPE), we will probably see some showers and non-severe
thunderstorms. These will probably be a combination of diurnally
and synoptically forced. They will probably organize themselves
such that there will be periods of rain/thunder and periods
where there is sunshine, particularly Monday afternoon in peak
diurnal heating.

Tuesday through Thursday, we settle into a west/northwest flow
pattern with broader ridging to the west. This is looking to be
a generally quiet weather period, though there are some hints
that there could be a weak passing upper level wave that could
bring some showers around Wednesday or so. As the ridge axis and
attendant surface high pass through Wednesday-Thursday, we may
get a southerly flow pattern for the end of the week, which
could bring more warm air and moisture advection north. We could
see some warmer temperatures and perhaps more thunderstorm
chances with that.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 630 AM CDT Sun Jun 29 2025

Some fog looks like it may persist for an hour or so at BRD/HIB.
After that, mainly VFR conditions expected today with
occasionally breezy conditions with gusts up to 15 kt at some
terminals. There is a possibility for some isolated to scattered
thunderstorms this afternoon, though timing of these and whether
or not they will directly impact terminals on the Minnesota side
is highly uncertain. The best chances for storms this afternoon
will be at HYR (50-60% chance). There is about a 5% chance that
any storms may be strong to severe there as well, with large
hail and damaging winds being the main threats. There should be
some partially clearing skies this evening, and while VFR
conditions should prevail, there is ~50% chance that there could
be some dense fog developing, mainly around HYR, later this
evening and overnight.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 332 AM CDT Sun Jun 29 2025

Aside from some lingering gusty and erratic winds as
thunderstorms pass through, winds are expected to settle to
light southwesterlies just after sunrise. Wind gusts are
expected to pick up to around 15 kt this afternoon. Isolated
thunderstorms are possible this afternoon and early evening as
well. A storm or two capable of producing some large hail to
quarter size or wind gusts to 50 kt can`t be ruled out, but it`s
only a 5% chance. Winds will remain southwesterly predominantly
into Monday, and some gusts to around 20 kt are possible.
Additional non-severe storms are possible on Monday (50%
chance).

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...JDS
MARINE...JDS