979
FXUS63 KDLH 151747
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1247 PM CDT Wed Jul 15 2026

.KEY MESSAGES...

- Lingering heat today through Friday with a bit less humid
  conditions. Heat Advisories may still be needed through the
  remainder of the week.

- Near-critical fire weather conditions are possible today.
  Smoke is expected to bring poor air quality to most of the
  region into at least Thursday.

- Better chances for showers and thunderstorms arrive Thursday
  into Friday.

- Very limited visibility on Lake Superior with a dense marine
  smoke advisory in effect for the ongoing wildfire smoke.

&&

.UPDATE...
Issued at 255 AM CDT Wed Jul 15 2026

The frontal boundary that worked southward overnight has setup
across central Minnesota and into northwest Wisconsin. This is
seeing a decreasing in dewpoints from north to south, with this
trend forecast into today. A line of non-severe thunderstorms
has formed on the northern periphery of this boundary early this
morning and is forecast to continue from Bemidji to Duluth into
the commute hours...slowly moving southward into the Brainerd
Lakes in this time. This frontal-associated convection is shown
to die off by mid-morning today in high-res guidance. Towards
the afternoon hours today, there is a 10-20% chance of high-
based rain showers and skirting the International Border. Any
precipitation is expected from a tenth of an inch or less in
localized spots into this afternoon. Given the uncertainty in
coverage and amounts of rainfall from these afternoon showers,
there are minimal locations that have actual rain showers
mentioned in the deterministic forecast though.

Daytime temperatures today and Thursday were cooled up to a few
degrees for the smoke moving southward and helping to dampen
the daytime MaxTs for most areas. This resulted in a South Shore
counties being dropped from the Heat Advisory and Sawyer County
being changed to a Heat Advisory today in place of the previous
Extreme Heat Warnings. All other Heat headlines remain in place.

Light winds under 10 mph are expected today as minimum relative
humidity down to 28-38 percent is forecast. A Special Weather
Statement was issued for the Iron Range and northward in far
northern Minnesota to continue to highlight a possible near-
critical fire weather potential this afternoon and evening given
these moderately dry conditions after the last few days of
critical fire weather conditions.

There remains a 20-30% chance of rain showers north of the Iron
Range late Wednesday night into Thursday morning, but mainly
west of US Hwy 53 for the Borderlands. The much higher rain
chances east of US Hwy 53 into the interior Arrowhead begin
Thursday night when a quarter-inch to half-inch of rainfall is
forecast by Friday evening.

The previous Air Quality Alerts from MNPCA and WiDNR remain in
effect as they were last evening. Smoke is modeled into all
parts of the region except northern Itasca County and
Koochiching County today. The latest air quality current
conditions and forecasts can be found on the MNPCA website and
the WiDNR websites to help keep informed about the coming days
air quality conditions.

&&

.DISCUSSION...
Issued at 304 PM CDT Tue Jul 14 2026

High pressure was centered over the Mid-Mississippi Valley early
this afternoon and extended eastward to the Mid-Atlantic. It also
stretched northwestward into the Northern Plains and Canadian
Prairies. A cold front extended from northern Quebec southwestward
across southern James Bay, northwestern Ontario, and into northern
Minnesota and North Dakota. This front will move south this
afternoon and into tonight before stalling out across central
Minnesota and northern Wisconsin. There isn`t a strong push of
cooler air behind the front, but winds will turn northwesterly as it
passes and help scour out the very high dewpoints that have been in
place. Ahead of the front, highs will again be in the 90s with 60s
and low 70s dewpoints keeping dangerous heat conditions in place. An
Extreme Heat Warning remains in place for almost all of the
Northland into this evening. There remains a small chance (30%
or less) of an isolated shower or thunderstorm ahead of the
front. CAMs were a bit more robust with this activity overnight,
but have backed off in more recent runs. However, a line of
storms did develop around midday along the front, but quickly
fizzled out.

Critical fire weather conditions remain in place across northern
areas with dewpoints crashing in the wake of the cold front.
This has dropped RH values into the 20 to 30 percent range with
northwesterly winds at 5 to 15 mph. A Red Flag Warning remains
in effect in this area. With the drier air continuing to push
southward behind the front tonight, RH recovery is expected to
be poor with values topping out in the 50-60% range north of US
2. Near-critical fire weather conditions will be seen across
almost all of the Northland tomorrow with afternoon RH values
falling into the 20 to 35% range. Winds will be northerly to
northeasterly at 6 to 12 mph.

As winds become northwesterly behind the cold front tonight,
wildfire smoke is expected to spread to the southeast over Lake
Superior and then turn southwesterly across northwest Wisconsin
into the Twin Ports and east-central Minnesota Wednesday. Smoke
is expected to be rather thick across northeastern Minnesota
and much of northwestern Wisconsin are forecast to reach Maroon
(Hazardous to all) to Purple (Very Unhealthy to Everyone)
levels. Air Quality Alerts have been issued for all of the
Northland through at least Thursday.

The front looks to stall out across central Minnesota with
northwest flow persisting aloft. As various shortwaves round the
trough axis and move through the region along with upward motion
across the stalled front/warm front, there will be low chances
for showers and thunderstorms Wednesday into Thursday. Highs
Wednesday will range from the middle 80s north to lower 90s
south. With not much cooling tonight and highs again in the 90s
tomorrow, have extended the Extreme Heat Warning for our
southern tier of counties, aside from Price, with a Heat
Advisory for the next tier north and Price County. Areas north
of there do not have any headlines at this time with highs in
the 80s and much less humid. Highs Thursday look similar with
perhaps a bit more humid conditions to the south and additional
headlines may be needed. A lake breeze is expected to develop
Thursday with northeasterly winds across Lake Superior. This
will keep areas near Lake Superior in the 70s and lower 80s and
bring an increased chance for rip currents to Twin Ports
beaches.

A stronger shortwave will propagate through the Upper Midwest
late Thursday into Friday and bring an area of low pressure
through the region. This will bring better chances for showers
and thunderstorms during this time, but questions remain as to
where the best rainfall will occur. Some models keep the best
rainfall across Canada in addition to timing differences. With
this package, the Arrowhead has the best chance of seeing at
least 0.50 inches from this system. Beyond that, there are hints
of a stronger system for the Sunday into Monday timeframe with
an upper low passing to our north. Temperatures will remain
above normal through the weekend in the 80s before trending
closer to normal heading into next week with highs in the 70s
and 80s.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1240 PM CDT Wed Jul 15 2026

VFR conditions will be interrupted by smoke from the wildfires
in the BWCA. Smoke will lead to MVFR/IFR visibilities. There
will be a brief improvement for most, if not all, terminals this
afternoon/evening, but is expected to return overnight. North to
northeast winds will veer to the east throughout the TAF period
and will largely remain below 10 kts.

&&

.MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 546 AM CDT Wed Jul 15 2026

Dense Marine Smoke Advisory issued for all of western Lake
Superior as the smoke is being observed to create visibilities
less than 1 nm. After this first round of smoke moves through
the Twin Ports to South Shore, a bit of improvement in
visibilities may occur this afternoon. This caused the Advisory
to be split into two different segments...one ending at Noon
today for Silver Bay to the Twin Ports and along the South
Shore. The other parts of the North Shore though were set to end
at 4 PM Thursday as there is much higher confidence in multiple
periods of visibility less than 1 nm are likely.

Another issuance though could easily be needed for the Twin
Ports and South Shore again tonight as model guidance helps
create moderate confidence in another round of limited
visibilities again this evening to tonight.


Previous Discussion 227 AM

Light winds today in the southwest arm and the Saxon Harbor
under 10 knots. Westerly winds remain though between Grand
Portage and Isle Royale though this afternoon and may still gust
to 20 knots given the terrain funneling. No headlines are
currently in effect though. Those northeast winds increase in
speed for the southwestern arm of the lake Thursday and are
likely to create conditions hazardous to small craft Thursday
afternoon and evening. Gusts to 25 knots are forecast and waves
may build to 3 feet in the Twin Ports.

Expect reduced visibility over most waters today and at least
Thursday, potentially into the end of the work week as the
wildfires in MN and Ontario continue.

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

&&

.FIRE WEATHER...
Issued at 251 AM CDT Wed Jul 15 2026

The frontal boundary that worked southward overnight has setup
across central Minnesota and into northwest Wisconsin. This is
seeing a decreasing in dewpoints from north to south, with this
trend forecast into today. A line of non-severe thunderstorms
has formed on the northern periphery of this boundary early this
morning and is forecast to continue from Bemidji to Duluth into
the commute hours...slowly moving southward into the Brainerd
Lakes in this time. This frontal-associated convection is shown
to die off by mid-morning today. Towards the afternoon hours
today, there is a 10-20% chance of high-based rain showers and
skirting the International Border. Any precipitation is expected
from a tenth of an inch or less in localized spots into this
afternoon. Given the uncertainty in coverage and amounts of
rainfall from these afternoon showers, there are minimal
districts that have actual rain showers mentioned in the
deterministic forecast though.

Daytime temperatures today and Thursday were cooled up to a few
degrees for the smoke moving southward and helping to dampen
the daytime MaxTs for most areas. This forecast change resulted
in an increase of a few percent for the afternoon MInRHs today.
Even with this though, light winds under 10 mph are forecast
today as minimum relative humidity down to 28-38 percent is
forecast as well. A Special Weather Statement was issued for the
Iron Range and northward in far northern Minnesota to continue
to highlight a possible near-critical fire weather potential
this afternoon and evening given these moderately dry conditions
after the last few days of very hot temperatures.

Recovery RHs tonight are forecast in the 75-85% range, a notable
increase from the last few days. There remains a 20-30% chance
of rain showers north of the Iron Range late Wednesday night
into Thursday morning, but mainly west of US Hwy 53 for the
Borderlands. The much higher rain chances east of US Hwy 53 into
the interior Arrowhead begin Thursday night when a quarter-inch
to half-inch of rainfall is forecast by Friday evening.

Air Quality Alerts are in effect through Thursday in Wisconsin
and Friday in Minnesota given the wildfire smoke.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory until 9 PM CDT this evening for MNZ033-034-036-
     038.
WI...Heat Advisory until 9 PM CDT this evening for WIZ006>009.
MARINE...Dense Smoke Advisory until 4 PM CDT Thursday for LSZ121-
     140>148-150.

&&

$$

UPDATE...NLy
DISCUSSION...BJH
AVIATION...KML
MARINE...NLy
FIRE WEATHER...NLy