textproduct: Duluth

KEY MESSAGES

- Areas of smoky conditions continue through the weekend, although not as widespread as the previous couple of days.

- Rain and storm chances return Sunday with the best chances being Sunday night into Monday. Strong to severe storms will be possible.

- Strong northwest winds on Tuesday may lead to more widespread coverage of smoke across the Northland

UPDATE

Issued at 143 AM CDT Sun Jul 19 2026

High pressure was leading to mainly clear skies across the Upper Midwest early this morning. A few isolated showers were seen on radar across north-central Minnesota, but this activity was decaying as it entered the Northland. Areas of smoke were evident across northwest Wisconsin and along the North Shore, leading to reduced visibilities. Warm temperatures are expected today with highs in the 80s and lower 90s. With a Moderate Heat Risk over most of the area along with Wet Bulb Globe Temperatures reaching into the lower 80s, a Heat Advisory has been issued for most of the Northland. Did not include the southern Lake zone, but Heat Advisory conditions will be seen from Knife River to Two Harbors with slightly cooler conditions east of Two Harbors.

In terms of chances for showers and thunderstorms later today, CAMs have been keying in on a cluster of storms developing this afternoon across northwestern Ontario and then moving southeast late this afternoon across the Arrowhead then across Lake Superior. Additional storms will be possible across the Arrowhead behind this cluster through the remainder of the evening. Additional storms will then be possible through the overnight hours. Any of these storms through the day and overnight may be strong to severe with damaging wind gusts to 60 mph and large hail being the primary threats. A Marginal Risk for severe storms from the SPC is in place across the entire Northland for today. Little changes to the forecast for Monday and beyond with another round of strong to severe storms expected Monday ahead of a cold front with all modes of severe weather possible.

DISCUSSION

Issued at 150 PM CDT Sat Jul 18 2026

Today:

Some lingering smoke in the morning hours will be possible across NW WI, the Twin Ports and the Arrowhead. Southwest to westerly winds will begin to stream across the region as high pressure scoots to the east. Smoke and air quality conditions will improve through the afternoon.

An upper level ridge will be in place over the region but an embedded shortwave is expected to ride along its edge and could produce some light rain showers (20% chance) across the International Border in the afternoon. The better chances for precipitation look to arrive in the overnight hours via an occluded system traversing across Manitoba and into Ontario. Placement and exact timing of the bands of precipitation remain contested when comparing the available high res guidance. Warm sector precipitation can always get tricky with where the best forcing of ascent will line up. Most of the guidance seems to be keying in on a strong shortwave that ejects out of the Northern Plains ahead of an upper level jet. MUCAPE in excess of 1000 J/kg with an EML will help to grow some elevated storms with damaging winds and large hail being the primary threat Sunday night into Monday morning.

Monday/Tuesday:

Continued shower and storm chances for Monday as the low pressure system in Canada meanders to the southeast. It's associated cold front will also slide through the region leading to a wind shift from out of the southwest to out of the west. Pending placement of the cold front we will see strong to severe storms develop once again. The convective parameter space looks increasingly favorable for Monday with high MLCAPE and strong upper level shear available for supercell growth. Increased low level helicity may also support a tornado threat to go along with the hail and damaging winds. SPC has a marginal risk (1/5) for MN and a slight risk (2/5) for NW WI.

Tuesday should be a dry forecast but an increasing pressure gradient over the region will lead to strong northerly winds. This may lead to another round of widespread Air Quality Alerts as smoke plumes from the wildfires could engulf the region once again.

Midweek

Winds weaken on Wednesday as high pressure moves over the region. Next chances for precipitation arrive on Thursday behind the departure of the high pressure. Not a lot of consistency among the suite of 12Z deterministic guidance but there are signals for a few ridge runners within our northwest flow to spawn some rain. For now we are carrying PoPs of 20-30% through Friday with Friday having more widespread coverage.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 640 AM CDT Sun Jul 19 2026

There are a few areas of showers out there, and a stray rumble or two of thunder can't be ruled out. These may affect HIB/DLH within the next 1 to 3 hours briefly. Otherwise, expect primarily VFR conditions through the day and early evening. Winds may become blustery at times with some gusts from 15 to 20 kt from the west to southwest. There is a ~10% chance that there could be stray showers through the day today with warm advection ongoing, but very low confidence on where or if showers will pop up. A warm/occluded front will bring a better chance for rain and thunderstorms overnight. Strong winds and hail can't be ruled with isolated coverage. MVFR visibilities due to smoke may be possible mainly at HYR today.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 143 AM CDT Sun Jul 19 2026

Winds will be southwesterly today at 5 to 15 knots, highest near the Twin Ports and near Grand Portage. Winds then go light and variable tonight before increasing Monday from the southwest at 5 to 15 knots with gusts to 20 to 25 knots in the western arm of the lake and along the North Shore from Grand Portage to Grand Marais. A cold front then move across western Lake Superior Monday afternoon and turns winds northwesterly, still at 5 to 15 knots with gusts to 20 to 25 knots in the western arm and along parts of the North Shore. Conditions hazardous to small craft will be possible Monday and Monday night. Thunderstorms may move across the lake later this afternoon into this evening with additional storms late tonight and again on Monday. Smoke along the North Shore east of Taconite Harbor and along the South Shore east of the Bayfield Peninsula may lead to visibility reductions at times today into tonight.

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

FIRE WEATHER

Issued at 143 AM CDT Sun Jul 19 2026

Warm and dry conditions will prevail today with highs in the 80s and lower 90s with afternoon RH values falling into the 35 to 45% range over most of the region. Winds will be southwesterly at 5 to 15 mph. Chances for showers and thunderstorms will be seen this evening and overnight. Some of the storms overnight may be strong to severe with damaging winds and large hail as the main threats. Monday will see highs in the 80s with afternoon RH values generally around 40% and higher. Additional showers and thunderstorms will be possible with strong to severe storms possible across the Minnesota Arrowhead into northwest Wisconsin. All modes of severe weather will be possible Monday afternoon before changing to a mainly damaging wind threat Monday evening. Rainfall amounts will be around a tenth to 0.35 inches with heavier amounts in excess of an inch possible in thunderstorms. Winds Monday will be southwesterly at 5 to 15 mph with gusts to 20 to 25 mph. A cold front will move through during the late afternoon and early evening turning winds northwesterly behind it. These northwesterly winds will continue for Tuesday with gusts to 25 mph.

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 8 PM CDT this evening for MNZ010>012-018-019-025-026-033>038. WI...Heat Advisory from 11 AM this morning to 8 PM CDT this evening for WIZ001>003-006>008. MARINE...None.