textproduct: Duluth

KEY MESSAGES

- Isolated showers and a few, non-severe storms through early evening in far northern Minnesota, the Minnesota Arrowhead, and northwest Wisconsin.

- Scattered showers and storms with a cold/occluded front on Friday, with the best thunderstorm coverage along and south of the US Hwy 2 corridor.

- There is a 5 to 10% chance of strong to severe storms Friday afternoon and evening south of US Hwy 2 in northeast Minnesota and in northwest Wisconsin. Main hazards would be hail up to 1 inch in diameter and wind gusts to 50 mph.

- Temperatures gradually warming each day into next week, but generally slightly below normal with highs in the mid 60s to mid 70s and low temperatures in the 40s to around 50 most nights. For comparison, normal highs are mid to upper 70s and normal lows are upper 40s to mid 50s.

DISCUSSION

Issued at 1254 PM CDT Thu Jun 18 2026

Rest of Today - Tonight:

In the wake of a surface cold front, seasonably cooler air remains over the Northland with highs topping out in the mid-60s to low 70s this afternoon, warmest in NW WI. Weak shortwave troughing energy aloft moving through the region along with cold air advection will keep isolated to widely scattered showers and a few general storms going through early this evening for the MN Arrowhead and portions of NW WI. Rainfall amounts will be isolated and largely a few hundredths of an inch or less, though any storms could produce a quick tenth or two of an inch (20% chance). Northwest wind gusts to 15-25 mph diminish towards sunset this evening with winds becoming light and variable to calm overnight. Also expect some patchy fog development tonight given calming winds and clear skies, particularly for areas that see any rain today. Widespread fog or dense fog are not expected.

Friday:

A week mid/upper-level shortwave trough moves through as surface low pressure slides along the international border and brings a cold/occluded front west to east across the Northland. PWATS around 0.8-1.0" along with surface dew points around 50-55F will provide enough moisture for scattered rain showers and thunderstorms to develop on Friday along and ahead of the surface front. High-res model forecast instability continues to trend higher for the afternoon through mid-evening hours, with MLCAPE of 200-500 J/kg in most of NE MN and 300-800 J/kg in the Brainerd Lakes east into NW WI. The combination of higher instability in the south combined with 25-40 kt of bulk shear, steeper low-level lapse rates, and marginal mid-level lapse rates around 6-6.5 deg C/km would support an isolated, marginally strong to severe wind gust/hail threat with any discrete storms that develop (5-10% chance). The hazards with the strongest storms would be wind gusts up to 50 mph, hail up to 1" in size, frequent lightning, and locally heavy downpours. Thunderstorm intensity wanes towards sunset, so the window of strong to severe storm potential is mainly in the 1 PM - 9 PM timeframe. Precipitation then ends west to east in the evening to overnight hours Friday night. Probabilities for >0.25" of rainfall on Friday are 50-70% for much of NE MN along and west of the US Hwy 53 corridor, highest in north-central MN. These same areas have a 20- 40% chance for >0.5" of rainfall, mainly tied to locations where thunderstorms move through.

Outside of showers and storms, expect increasing cloud cover on Friday, then some clearing in north-central MN towards sunset as the cold front moves through. Expect daytime wind gusts to around 15 mph and high temperatures in the mid 60s to low 70s.

This Weekend:

Surface high pressure moving east from the Dakotas slides through the Upper Midwest on Saturday and east into the Great Lakes on Sunday. This will lead to a predominately drier air mass over the Northland. With that said, a cut-off low aloft that has been churning near the northeast Manitoba/far northwest Ontario border will eventually dig southeast towards Lake Superior sometime late Saturday or Sunday, though ensemble members and deterministic mid- range models are in disagreement on how quickly the low moves and how far south it digs, as is typically the case with these cut-off lows. Therefore, we can't completely rule out some isolated rain shower potential (10-40% chance) mainly in the MN Arrowhead on Saturday or to a lesser extent on Sunday, but precipitation coverage and amounts should be limited in nature due to the overall drier air mass in place.

Temperatures warm a few degrees for this weekend with highs in the mid 60s to mid 70s and partly cloudy to mostly sunny skies. Northeast winds on Sunday should produce slightly cooler temperatures near Lake Superior and the Twin Ports.

Early Next Week:

Fairly good agreement in the pattern aloft for early next week as a mid/upper-level trough currently (i.e. today/Thursday) over the Gulf of Alaska dives southeast across British Columbia on Friday and the southern Canadian Prairies this weekend. That system then slides east/southeast through southern Saskatchewan, Manitoba, and the Upper Midwest through the first half of next week. An associated low pressure system also moves through during the same timeframe, with a cold front extending south through the High Plains on Monday, to western MN by Tuesday, and through our region sometime late Tuesday into Wednesday. Ahead of this system, northeast surface winds are likely on Monday before becoming southerly on Tuesday. Temperatures remain pretty consistent in this timeframe in the upper 60s to mid 70s, with slightly cooler temperatures near Lake Superior. Warm advection/isentropic ascent ahead of this front should bring in widespread showers and embedded storms on Tuesday from west to east, then along and ahead of the front late Tuesday into early Wednesday as the front moves through. Still a bit early to pin down potential for strong or severe weather with this system, but the origin of this system in the Pacific northwest combined with a lack of adequate Gulf moisture from our south favors a more limited instability setup and weaker storms. Cyclonic flow behind the departing low/front on Wednesday would also support lingering scattered shower and storm chances.

Late Next Week and Beyond:

Models diverge in the mid/upper level pattern for the latter half of next week into next weekend, but the latest CPC outlooks for late June favor slightly above normal precipitation with near normal temperatures favored.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1254 PM CDT Thu Jun 18 2026

BKN MVFR ceilings early this afternoon at HIB and DLH before SCT to BKN ceilings rise to VFR for the remainder of the afternoon. Scattered showers continue at INL this afternoon and may occasionally make their way near HIB before diminishing this evening. Also expect scattered showers and isolated storms in the Minnesota Arrowhead and north-central Wisconisn, but precipitation should mainly stay east of HYR this afternoon. West to northwest wind gusts to 15 to 25 knots persist through early evening before becoming light and variable to calm tonight. VFR conditions prevail in mostly clear skies tonight into early Friday morning, though there is a 10% chance for patchy fog tonight. Probability of fog was too low to include in the current TAF update. Rain showers begin to move in from the west Friday morning ahead of an approaching cold front, becoming scattered showers and thunderstorms Friday afternoon. BRD and HIB have the best potential to see rain showers move in very late in the current 18Z TAF period late Friday morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1254 PM CDT Thu Jun 18 2026

Westerly winds at 5 to 15 kts today become northwesterly at 5 to 15 kts for this evening and tonight. Isolated showers and a few non-severe thunderstorms will be possible this afternoon into this evening along the North Shore, primarily east of Taconite Harbor. Winds back to southwesterly on Friday at 5 to 15 kts, with some gusts of 15 to 20 kts from Grand Marais to Grand Portage Friday afternoon. Winds become westerly at 5 to 10 kts Friday night. Scattered showers and non-severe thunderstorms will be possible again during the afternoon and evening hours in the western arm of Lake Superior, with the best chance for any thunderstorms near the Twin Ports. Southwest winds develop again for Saturday at around 10 kts or less.

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

FIRE WEATHER

Issued at 1254 PM CDT Thu Jun 18 2026

Scattered light rain showers across far northern Minnesota, the Minnesota Arrowhead, and northwest Wisconsin for this afternoon into early evening. Isolated, non-strong or severe storms will occur at times, too. Expect only a few hundredths of an inch of rain where precipitation does fall, and locally 0.1-0.2" where a thunderstorm moves overhead. Min RH remains at or above 40% across the areas today and recovers to 85-100% tonight.

Better coverage of scattered to widespread showers storms are expected on Friday along and ahead of a cold/occluded front, especially for north- central Minnesota, the Brainerd Lakes, and east into northwest Wisconsin. Around or less than 0.1" expected for the Arrowhead and far northern Minnesota, but 0.1-0.4" elsewhere. Areas that see storms could see localized amounts in excess of 0.5", as well. A few storms could be strong to severe in the Brainerd Lakes east to northwest Wisconsin. Hail up to 1", wind gusts to 50 mph, frequent lightning, and locally heavy downpours are the hazards with the strongest storms. Min RH is once again expected to be at or above 40% on Friday.

Mainly conditions return for Saturday, but RH values are currently forecast to dip to 35-50% across the area. 20-50% chances for isolated showers and an embedded weak storm or two remain on Saturday in the tip of the Arrowhead. Winds will also be lighter into the weekend at 5 to 15 mph out of the northwest on Saturday and northeast on Sunday, with daytime winds strongest in the afternoon both days. Temperatures will be in the 60s and lower 70s through Saturday then warming into primarily the low to mid 70s for Sunday into next week.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...None.