319
FXUS63 KDLH 270625
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
125 AM CDT Fri Jun 27 2025

.KEY MESSAGES...

- An area of rain and a few thunderstorms will lift
  northeastward across the Northland this afternoon and tonight.
  Additional rainfall amounts of 1 to 2 inches are forecast
  over northwest Wisconsin with lower totals farther west.

- There is a 10 to 20 percent chance of flash flooding over
  portions of Sawyer, Price, and Iron counties tonight.

- Strong to severe thunderstorms are possible late Friday night
  through Sunday evening.

- Warm and humid weather is expected this weekend.

&&

.DISCUSSION...
Issued at 345 PM CDT Thu Jun 26 2025

Tonight:

A shortwave trough axis stretched from southwest Manitoba to
eastern Nebraska this afternoon. A nearly stationary boundary
has begun to move northward in response to strengthening
southerly winds over eastern Iowa and deepening low pressure
over northwest Iowa. An area of rain and embedded thunderstorms
was found over the northern two-thirds of Minnesota and west-
central Wisconsin.

Expect the rain to spread northeastward with time tonight.
Elevated instability will spread northward into northwest
Wisconsin this evening and a few thunderstorms are likely over
that area tonight. Severe weather is not anticipated. Much of
northwest Wisconsin received rainfall yesterday and soils have
less capacity to absorb more rain today. The potential for
thunderstorms causing locally enhanced rain rates may lead to
localized flash flooding. There is a 10 to 20 percent chance of
flash flooding over portions of Sawyer, Price, and Iron
counties. Rain amounts tonight of up to one-half inch are
forecast over portions of the Arrowhead into central Minnesota
while another 1 to 2 inches is forecast over northwest
Wisconsin.

Friday:

High pressure develops for Friday with increasing sunshine
expected. Temperatures will climb into the upper 60s to upper
70s. Temps will be coolest Ashland, Iron, and Price counties
where rain-laden soils and loitering cloud cover will limit
heating response.

Strong northeast winds over western Lake Superior will continue
the risk of rip currents for the beaches of Duluth and
Superior.

Friday night and Saturday morning:

Southerly flow will bring plenty of warm and moist air into the
Northland for the weekend. An initial shortwave trough and a
strengthening low-level jet across the Dakotas Friday
evening/night may prompt an MCS to develop in North Dakota or
the southern portions of Saskatchewan and Manitoba. If the MCS
does develop, the low-level jet may sustain the complex as it
propagates eastward overnight. Storms may move into the
Northland from the west during the early morning hours of
Saturday, between 3 and 7 AM. There remains a "Marginal" (1 out
of 5) risk of severe storms early Saturday morning. The main
threat will be damaging wind gusts, although a few hailstones of
dime to penny size are also possible. The storms will continue
to propagate eastward across the Northland late Saturday morning
through early afternoon.

Previous discussion for Saturday afternoon through early next
week below...

As we go into Saturday afternoon, instability will be on the
increase (MUCAPE rising to ~2-3 kJ/kg into late Saturday
afternoon/night) with ~30-40 kt of 0-6 km shear. The question
will be how soon a cap can bust for storms to develop given the
potential for morning convection, which may keep things stable
perhaps well into the afternoon. The best synoptic forcing may
be displaced over the Dakotas/Minnesota border with a weak
occluded front may be. But with all that said, if the cap can be
busted, soundings initially look favorable for all hazards;
large hail and damaging winds being the main threats, but with a
tornado or two not out of the question. As is often the case,
this could start with some discrete convection, then become a
bit more organized into Saturday evening/night, but there`s
still a lot of unknowns about how everything will come together.

On Sunday, a cold front passing through will probably trigger
another round of thunderstorms, possibly strong to severe, with
northwest Wisconsin being the most likely place to be affected.
With the front passing through, this looks like it would be
mostly a hail/wind situation than anything else, but it`s really
too soon to be very precise about the nitty-gritty details.

With the storm talk out of the way, the southerly flow is still
expected to bring hot and humid temperatures to the Northland
both Saturday and Sunday. At this point, it`s looking slightly
less favorable that widespread Heat Advisories will be needed,
with some of that uncertainty owing to aforementioned storm
potential, which could cool things off a bit. Still, heat
indices approaching or hitting 90 degrees with highs in the 80s
and dew points in the 60s to low 70s will lead to some
unpleasant conditions for those sensitive to or generally
disliking hot weather.

Early next week:

We had previously been advertising mainly quiet weather, but at
least on Monday, there is potential for a trough to pass
through with west to northwest flow. This could lead to some
wraparound-style showers and perhaps storms (most likely non-
severe). Tuesday may be quieter, but then perhaps a cold front
going into Wednesday to keep things interesting. In general,
temperatures are looking to be around to a bit above average
early to mid-week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1225 AM CDT Fri Jun 27 2025

Light rain showers will eventually exit to the northeast over
the next several hours into the early morning, with areas of
MVFR to IFR fog mixed in with the rain. Then, expect ceilings to
lower to LIFR to IFR for most terminals into the early morning
hours in low stratus and fog aside from INL/far north-central
Minnesota. HYR and possibly DLH could even touch VLIFR ceilings
at times with IFR fog. Otherwise, visibilities in areas of fog
will be more MVFR elsewhere. Gradually see visibilities and
ceilings improve towards mid to late morning, with VFR
conditions returning for most terminals by mid to late
afternoon. INL is expected to remain VFR throughout the TAF
period.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 123 AM CDT Fri Jun 27 2025

Update: Issued a Small Craft Advisory for the remainder of the
North Shore through mid-morning. Gusty winds approaching 25 kt
have been observed and are expected to persist through just
after sunrise. No other changes since the previous discussion.

Previous Discussion:

Strong and persistent northeast winds will
continue today and Friday and will gradually weaken Friday
afternoon. Dangerous wind and waves is forecast overnight
through Friday morning and Small Craft Advisories were extended.
A few thunderstorms are possible tonight from Port Wing to
Saxon Harbor. Cloud-to-water lightning is the main threat. There
is another chance of thunderstorms Saturday morning and
Saturday evening into the overnight. A few storms may be strong
to severe.

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 10 AM CDT this morning for
     LSZ140>148.
     Small Craft Advisory until noon CDT today for LSZ150.

&&

$$

DISCUSSION...Huyck/JDS
AVIATION...Rothstein
MARINE...JDS/Huyck