856
FXUS63 KDLH 170717
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
217 AM CDT Fri Jul 17 2026

.KEY MESSAGES...

- Smoky conditions early this morning, with some improvement for
  portions of the Northland today. Additional smoky conditions
  return this weekend.

- Hot temperatures and increased humidity once again in our
  southern and western counties today where a Heat Advisory has
  been issued.

- Two rounds of showers and storms are expected today. Severe
  weather most likely in the afternoon/evening. A quarter to
  half inch of rain possible where rain falls, with pockets to
  0.75 inches possible right along the International Border.

- Another system will move through early next week with more
  chances for showers and storms late Sunday into Monday
  followed by stronger winds and potential near-critical fire
  weather concerns for Monday and Tuesday.

&&

.DISCUSSION...
Issued at 216 AM CDT Fri Jul 17 2026

Today - Tonight:

Early this morning, a low-level jet is interacting with weak
shortwave energy aloft near and just north of the International
Border to kick off scattered showers and storms as noted by
regional radar imagery. This area of elevated convection has
access to 1000-1800 J/kg of MUCAPE along with effective shear of
30-40 kt. High-resolution models keep the bulk of this
precipitation across far northern Minnesota into northwest
Ontario through the current overnight through late morning
hours today, with the potential for mainly small hail, though
isolated quarter size hail can`t be completely ruled out. A
secondary threat of gusty winds also cannot be completely ruled
out, but given the elevated nature of the storms this should be
a lesser threat. Rainfall amounts with the morning round will
likely be 0.1-0.3" for most locations in far northern Minnesota,
though some pockets up to around 0.75" near the International
Border are possible where several storms in the cluster move
over the same location. While the rainfall would be helpful for
ongoing wildfires, it does not appear heavy or widespread enough
to mitigate fire concerns. Additionally, there is concern that
any lightning from these storms could potentially create more
wildfire starts.

Southwest winds develop ahead of a cold front today, which
should help push the densest smoke northeastward and lead to
clearer skies in our southern and western counties today. This
should result in high temperatures climbing into the upper 80s
to low 90s for all but the immediate Lake Superior/Arrowhead
vicinity and far northern Minnesota. Increasing dewpoints into
the mid 60s to low 70s today should also combine with these hot
temperatures to produce heat index values in the low to upper
90s. As a result, Heat Advisories have been issued for very late
this morning into evening generally along and south of US-2 in
northeast Minnesota and northwest Wisconsin.

By the mid to late afternoon, scattered showers and storms are
expected to develop along and ahead of the cold front as the
capping inversion breaks. This second round of storms should
have access to 1000-2000 J/kg of MLCAPE in addition to 30-40 kt
of effective shear, modest mid-level lapse rates (6-7 C/km), and
strong Downdraft CAPE due to steep low-level lapse rates. This
sets a parameter space where storms will be capable of large
hail and damaging wind gusts, and a lower-potential threat of a
tornado or two (2% chance). While brief downpours are possible
with any storm, coverage of rainfall will be limited and heavy
rain is not expected. Most of the active convection in the PM
hours today will also be south of the active wildfires. Storms
and the cold front track southeast into northwest Wisconsin this
evening before pushing south of the area tonight. Expect warm
temperatures to linger into tonight, with lows around 60-66F.

This Weekend:

In the wake of today`s cold front, high pressure moves into the
region for Saturday and most of Sunday, bringing dry and
primarily sunny conditions, outside of any smoke that is. With
winds being out of the northwest tonight and north on Saturday,
wildfire smoke is likely to make it`s way back into portions of
the Northland. We have dropped high temperatures a couple
degrees on Saturday (low to upper 80s) to account for decreased
solar insolation due to smoke. A shift to southwest winds on
Sunday may once again give reprieve from some of the wildfire
smoke for portions of the Northland, with high temperatures
climbing a few degrees again into the mid to upper 80s. Mostly
sunny skies on Sunday gradually see cloud cover increase later
in the day ahead of another approaching low pressure system and
cold front. While winds won`t be overly strong either day,
minimum relative humidity each afternoon into the 35-45% range
along with hotter temperatures could lead to some elevated fire
weather concerns.

Early to Mid-Next Week:

Shortwave energy diving southeast out of the Canadian Prairies
Sunday night into Monday will likely bring a return of scattered showers
and thunderstorms to the Northland. A strong cold front will
move northwest to southeast across the area during this
timeframe, and, depending on exact timing, could bring strong to
severe thunderstorm potential for portions of the Northland
Monday afternoon and evening with a favorable instability/shear
combination along and ahead of the cold front. In addition to
thunderstorm potential, this also poses concern for additional
near-critical fire weather conditions due to strong winds and
a 40-70% chance for wind gusts of 30 mph or more with and behind
the front on Monday and Tuesday. Drier air behind the front late
Monday and on Tuesday could push minimum relative humidities to
30-40% depending on the degree of drying, as well.

Expect high temperatures in the mid 80s to low 90s on Monday and
then cooling to the mid 70s to around 80F by the Tuesday-
Wednesday timeframe. While temperatures will be more seasonal,
there is not a strong signal for widespread or notable rainfall
by mid to late next week, so concerns remain for continued
drying in the region.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1245 AM CDT Fri Jul 17 2026

MVFR to LIFR visibilities and MVFR to IFR ceilings in smoke
continue into this morning. Scattered showers and storms are
near KINL to start the TAF period, with better potential towards
10-14Z associated with a cluster of convection moving east-
southeast out of southern Manitoba. Could see some small hail
and erratic, gusty winds for any storms that move directly over
the terminal, but the bulk of storms could stay just north of
the International Border. KHIB may also be on the far southern
extent of these showers/storms as they move east into the
Arrowhead this morning. Can`t rule out brief visibility
improvements to the smoke as the convection moves through.
Scattered shower and storm development is also possible mid
afternoon into this evening along and ahead of a west to east
moving cold front. Still some uncertainty as to where storms
exactly develop, but the best coverage and potential (30-50%
chance) would be in northwest Wisconsin/KHYR. Small hail,
erratic winds, and brief heavy downpours/MFVR conditions would
be possible with any of these storms.

Winds shift to southwesterly this morning and then veer to
northwesterly from west to east across the area as the cold
front moves through this afternoon and evening. The southwest
winds ahead of the front should aid in clearing and some improvement
of smoke conditions, especially at KBRD and KHYR mid to late
this morning, KINL by early afternoon, and KHIB/KDLH later this
afternoon.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 216 AM CDT Fri Jul 17 2026

A Dense Smoke Advisory remains in effect for all nearshore
waters until 7 PM CDT today as widespread wildfire smoke
continues to reduce visibilities to 1 nautical mile or less.
Northeast winds linger much of the day today, with some
afternoon gusts to around 15-20 kt near the head of the Lake
this afternoon and 1-2 ft waves. Showers and storms are
possible over portions of the North Shore this morning and
western Lake Superior late this afternoon and evening. A few of
the storms could be strong to severe with gale force winds and
large hail. Winds turn northwesterly behind a cold front this
evening and tonight with gusts to 10-20 kt, strongest along the
North Shore. Winds turn southerly and light for the remainder of
Saturday and southwesterly at 5-15 kt on Sunday, with reduced
visibility in smoke likely to continue at times when wind
directions do not have a southerly component.

For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.FIRE WEATHER...
Issued at 216 AM CDT Fri Jul 17 2026

Wildfire smoke will continue to linger through tonight. Today,
increasing temperatures and southwest winds are expected, but
minimum relative humidity stays at 40-60% as dewpoints increase
into the 60s to low 70s. Scattered showers and storms are
expected this morning in far northern Minnesota into the
Arrowhead and on a widely scattered basis along and ahead of a
cold front mid-afternoon into this evening. The morning storms
could produce small to quarter size hail and erratic, gusty
winds. The afternoon/evening storms could produce strong to
severe storms with large hail, damaging wind gust potential, and
a lower chance for a tornado or two (2% chance). Rainfall
amounts for far northern Minnesota will generally be 0.1-0.3",
with localized amounts to 0.75" possible near the International
Border. Light northerly winds of 5-10 mph with daytime gusts of
10-15 mph and southwest winds of 6-12 mph with 12-18 mph gusts
on Sunday combine with minimum RH of 35-45% to potentially
produce pockets of elevated fire weather conditions. A strong
cold front Sunday night into Monday will veer winds
northwesterly with gusts to around 30 mph Monday into Tuesday
and minimum RH values of 30-40% Monday and Tuesday, especially
behind the cold front. While scattered showers and storms are
likely with and ahead of the cold front, widespread heavy rain
is not expected and the drier conditions and strong winds behind
the front could lead to near-critical fire weather conditions.
High pressure also develops into mid-next week, keeping rain-
free conditions going for several days next week.

See the Fire Weather Forecast product for a more thorough
breakdown of fire weather conditions.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory from 11 AM this morning to 9 PM CDT this evening
     for MNZ018-025-026-033>038.
WI...Heat Advisory from 11 AM this morning to 9 PM CDT this evening
     for WIZ001>004-006>009.
MARINE...Dense Smoke Advisory until 7 PM CDT this evening for LSZ121-
     140>148-150.

&&

$$

DISCUSSION...Rothstein
AVIATION...Rothstein
MARINE...Rothstein
FIRE WEATHER...Rothstein