Isabella, Minnesota Weather Forecast Discussion

422
FXUS63 KDLH 110930
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
430 AM CDT Thu Sep 11 2025
.KEY MESSAGES...
- Dense fog this morning will dissipate by late morning. Expect
  another round of dense fog tonight and Friday morning.
- There is a 10 to 30 percent chance of thunderstorms north of
  US-2 Friday morning. The risk of storms shifts east into the
  Arrowhead, western Lake Superior and northwest Wisconsin by
  late afternoon through the evening. A few storms may be strong
  Friday morning over north-central Minnesota.
- Above normal, summer-like, temperatures this weekend with
  highs in the low 70s to low 80s away from Lake Superior.
- On and off chances for showers and thunderstorms return late
  Sunday and continue through the first half of the week.
&&
.DISCUSSION...
Issued at 430 AM CDT Thu Sep 11 2025
Dense fog spread inland from Lake Superior overnight with
radiational fog found farther inland. Dense Fog Advisories
remain in effect until 11 AM. Anticipate visibility of 1/4 mile
or less. Light drizzle was falling near Lake Superior where
northeasterly to southeasterly winds were creating upslope flow.
Expect the drizzle and fog to dissipate later this morning and
give way to mostly sunny skies.
High pressure over Ontario and low pressure over the northern
Plains will provide an ideal pressure gradient orientation for
strong northeast winds to develop over the southwest arm of Lake
Superior. The strong winds of 15 to 20 mph will build waves of
2 to 4 feet. The wind direction and wave action will create a
risk of rip currents this afternoon and evening. A Beach Hazards
Statement was issued from 1 PM until 10 PM. Wind and waves will
likely make swimming conditions challenging Friday into next
week.
Showers and storms are forecast to develop over the northern
Plains this afternoon and will be carried eastward on the nose
of a nocturnal low-level jet. The storms are forecast to move
across northern Minnesota from late tonight through late morning
Friday. Storm chances will be highest along the Canadian border
from about 5 AM until 10 AM Friday morning. This is also the
time of the greatest risk of strong to severe storms. Hail as
large as quarters and wind gusts as strong as 60 mph are
possible Friday morning.
The low-level jet will gradually weaken through the day.
Isentropic ascent is will continue keeping a 10 to 30 percent
chance of showers and storms in the picture over northeast
Minnesota through the day. The veering low-level jet will shift
the precipitation risk into northwest Wisconsin and the
Arrowhead by Friday evening.
A mid-level ridge will build over the Upper Mississippi River
Valley region this weekend into early next week. Southerly
theta-e advection will persist in the lower altitudes. Thus a
stretch of above normal temperatures are forecast this weekend
into early next week. Highs on Friday will reach the middle 60s
near Grand Marais to around 80 degrees farther inland. Saturday
and Sunday will seem summery with highs in the upper 60s to low
and middle 80s. Those values are near normal for portions of
the North Shore to around 15 degrees above normal for areas
inland from Lake Superior.
Several rounds of showers and storms are possible Sunday
through early next week as several shortwave troughs propagate
northward along the western periphery of the mid-level ridge. A
few of these storms could be strong, although the overall risk
of severe storms is low (less than 5%).
A pattern shift is forecast around midweek as a substantive
cold front moves southeastward out of the Canadian Prairies into
the Plains and western Great Lakes. Temperatures will trend
near normal for the second half of next week. Highs Thursday are
forecast in the middle 60s to low 70s.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 108 AM CDT Thu Sep 11 2025
Another night of fog and low ceilings across the area.
Visibility reports have fluctuated at the terminals this
evening. Added in BCFG to account for partial coverage of fog at
the airports which may or may not be coincident with the
observation equipment. Visibility and ceilings will improve
through late this morning. Expect VFR by 16Z. DLH poses a
slightly greater challenge. Fog over Lake Superior may advect up
the hill to the airport, thus visibility and ceiling reductions
may persist later than currently forecast.
Fog will redevelop around or after 12.06Z.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 430 AM CDT Thu Sep 11 2025
High pressure near Hudson Bay and low pressure over the
northern Plains will work together to create strong northeast
winds over the southwest arm of Lake Superior this afternoon and
tonight. Winds will be strongest near the Twin Ports at around
15 to 20 knots. A Small Craft Advisory may be needed for this
afternoon and tonight. Winds will be from the northeast over the
rest of Lake Superior though wind speeds will be lower, around
5 to 10 knots. Waves near the Twin Ports will build to 2 to 4
feet. Winds will gradually weaken tonight before strengthening
again Friday. A few thunderstorms are forecast over western Lake
Superior Friday and Friday night. The greatest risk of storms
will be from Silver Bay to Grand Portage and eastward over the
open waters. A few storms may be strong with hail to penny size,
wind gusts to 30 knots, and occasional cloud-to-water
lightning.
Northeast winds persist into the weekend. Generally lower
pressure will remain over the Plains and higher pressure will be
found over Ontario. Saturday into early next week is shaping up
to be quite warm over northern Minnesota and northwest
Wisconsin, which will create a strong thermal gradient along the
shore during the day. Thunderstorms over the northern Plains
will strengthen the low pressure over that area, which will
tighten the pressure gradient over Lake Superior and lead to
strong northeast winds Saturday into next week. Small Craft
Advisories may become necessary.
Additional rounds of storms are forecast Sunday through much of
next week.
For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Dense Fog Advisory until 11 AM CDT this morning for MNZ010>012-
     018>021-025-026-033>038.
     Beach Hazards Statement from 1 PM CDT this afternoon through
     this evening for MNZ037.
WI...Dense Fog Advisory until 11 AM CDT this morning for WIZ001>004-
     006>009.
     Beach Hazards Statement from 1 PM CDT this afternoon through
     this evening for WIZ001.
MARINE...Dense Fog Advisory until 1 PM CDT this afternoon for LSZ121-
     140>148-150.
&&
$$
DISCUSSION...Huyck
AVIATION...Huyck
MARINE...Huyck

NWS DLH Office Area Forecast Discussion