Shaw, Minnesota Weather Forecast Discussion

071
FXUS63 KDLH 152342
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
642 PM CDT Mon Sep 15 2025
.KEY MESSAGES...
- Isolated showers and storms are possible this afternoon and
evening. A strong to severe storm or two can`t be ruled out, mainly
along the Canadian Border.
- Warm to hot temperatures through Wednesday, then cooling off a bit
late-week into the weekend.
- On-and-off shower and storm chances through the week and into the
weekend.
&&
.DISCUSSION...
Issued at 1247 PM CDT Mon Sep 15 2025
A narrow corridor of clouds and showers has set up in the vicinity
of a warm front. Instability has been building pretty quickly
during the early afternoon after getting rid of the morning
stratus and fog. The question for this afternoon is whether or
not some of this instability can be realized in the form of some
strong to severe thunderstorms. Working in favor of it is a
well-above-normal air mass and plenty of instability (~2000
J/kg or more locally expected at peak heating this afternoon)
and favorable effective bulk shear around 40 kt. Working against
it is a largely capped environment except perhaps around the
International border. CAMs have been pretty limited in producing
convection this afternoon as a result, but we remain with a
chance regardless with the aforementioned ingredients in place
(in other words, the models could have it wrong). Generally
speaking, if storms do pop up, they are likely to be pretty
isolated in coverage. But with that said, a storm or two capable
of producing some 60 mph wind gusts and/or hail up to ping pong
ball size can`t be ruled out, especially along and near the
International border where the cap is most likely to break. This
threat could linger into the evening a bit. Outside of that, we
will have the warm temperatures this afternoon.
Tonight, we may have some more fog developing in basically the same
places it did this morning. Overall probabilities for dense fog and
coverage of fog in general are looking less comparatively. The
higher terrain around the Twin Ports and possibly up the North
Shore, as well as the usual low spots up around the Iron Range, may
be the best contenders for some areas of dense fog Tuesday morning,
but there isn`t enough confidence that it will be widespread enough
to warrant any Dense Fog Advisories at this time.
Into Tuesday, it`s looking like a hot day around the Northland with
highs topping out in the 80s nearly everywhere, and even some mid
80s around Hinckley/Grantsburg. There should be some robust
instability developing in the afternoon and some low-end favorable
wind shear around 30 kt for thunderstorms. But, most models keep us
pretty capped through the afternoon. That said, there could be a bit
of upper-level waves passing through that could trigger some storms
in the evening. There could be a very brief couple hour window where
the cap could diminish and there could be some surface-based CAPE
that could be realized before temperatures cool off in the evening.
So, while chances for storms are relatively low (20-30% chance),
we`ll have to keep an eye out for a stray strong to severe storm in
the evening.
The last warm/hot day will be Wednesday, and we could see some areas
of showers and storms during the day as well. Shear looks overall
weak, but at least some instability possible mainly in northwest
Wisconsin. A stacked low may develop over the Dakotas around this
time, so we`ll be sitting on the warm air advection side of that,
though surface winds become more northeasterly with surface high
pressure to the north bringing in some cooler and drier air near the
surface.
For Thursday and Friday, temperatures are expected to cool off a
bit, especially around Lake Superior with the onshore flow. Various
upper-level lows should be hanging around and keeping some on-and-
off chances for showers going...perhaps a storm or two. Over the
weekend, we may slowly revert back to a southerly flow pattern.
Temperatures should be closer to seasonal averages, but may be a
touch warmer than average. The upper level pattern looks a bit wavy,
so shower chances should stick around.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 641 PM CDT Mon Sep 15 2025
A band of clouds with the potential to host showers and storms
generally extends from northwest WI north into the MN Arrowhead
this evening. A few showers and storms have developed along this
band earlier today, and there may be additional showers/storms
this evening, gradually becoming less likely tonight. Should
storms develop, they may bring a short period of IFR
visibilities and MVFR ceilings. Initially breezy conditions this
afternoon will gradually weaken this evening. Winds aloft of
30-40kts should produce LLWS for KDLH, KHIB and KINL overnight.
Winds veer to the southwest at 5 to 10 kts for Tuesday. Fog is
expected again tonight, DLH/HIB have the best chances for a
period of IFR fog in the morning hours. It is expected to lift
and mix out during the morning. Aside from that, VFR conditions
through the period.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 145 PM CDT Mon Sep 15 2025
Areas of fog are possible tonight, but there is only a ~30% chance
for seeing visibilities below half a mile, so no headlines will be
issued. Winds are expected to become light and variable tonight and
become light from roughly the southeast on Tuesday. Winds remain
light and variable Wednesday as well, then more persistent
east/northeast winds are expected Thursday and Friday with some
conditions that may be hazardous for small craft on Friday. There
will be on-and-off chances for isolated to scattered showers and
thunderstorms through the weekend. Severe weather is not expected at
this time, though a stronger storm or two capable of some gusty
winds or small hail is possible this afternoon and Tuesday
evening.
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 until 10 PM CDT this evening for
     MNZ037.
WI...Beach Hazards Statement until 10 PM CDT this evening for
     WIZ001.
MARINE...None.
&&
$$
DISCUSSION...JDS
AVIATION...LE
MARINE...JDS

NWS DLH Office Area Forecast Discussion