textproduct: Duluth

KEY MESSAGES

- Rain with scattered thunderstorms expected through this evening, especially in east-central Minnesota and northwest Wisconsin.

- Cooler and quieter conditions for the weekend.

- Isolated chance for showers Saturday afternoon along the North Shore. Afterwards the next chance for showers and storms is late Monday into Tuesday.

DISCUSSION

Issued at 1258 PM CDT Fri Jul 31 2026

This afternoon into tonight: Low pressure is passing through Iowa and southern Minnesota today with the bulk of the attendant synoptic rain to our south. We have had more thunderstorm activity up here this morning due to some convergence and a small amount of instability. That has resulted in some pretty good rainfall totals in the 1-3 inch range for a few areas, but this hasn't necessarily been widespread. Convection has really dropped off recently and we're left with mostly a broad area of light to moderate rain with a few embedded heavier showers. There hasn't been any lightning out there in a couple hours. With very limited instability now, this will likely be the case for another few hours early this afternoon. Later on, on the northern edge of the synoptic rain, we may expect a bit of redevelopment of some thunderstorms in northwest Wisconsin with some afternoon heating. Models still want to redevelop a few showers and perhaps storms along and around the North Shore as well, owing to some midlevel convergence. Any storms will remain sub-severe, and flooding concerns at this point are very minimal. Rainfall rates have at times been pretty impressive this morning, but with current rates winding down, even a brief uptick in rates this afternoon is not likely to cause much issues. Expect low pressure to move off to the east tonight, and any lingering showers and storms should end this evening from west to east.

Saturday through Tuesday: Ridging develops on Saturday aloft with drier air filtering in. There could be a few showers that develop Saturday afternoon in or around the Arrowhead with a weak embedded shortwave passing by aloft and some surface convergence possible as we get an east-northeast lake breeze and more northerly winds inland. Temperature-wise, we get more seasonable with highs in the 70s to low 80s. The 70s are expected around Lake Superior with onshore flow.

The onshore flow will persist into Sunday around Lake Superior, but inland, wind direction will switch to more east to southeasterly as surface high pressure to our north moves east and we get some return flow. Sunday's highs will be pretty similar to Saturday, but nighttime lows in north-central Minnesota start to climb a bit with warm air advection developing as we go into Monday.

Widespread low 80s are looking likely on Monday with pretty uniform southerly flow except onshore right by Lake Superior. A cold front is expected to move through Tuesday, and ahead of that Monday night, showers and thunderstorms are likely to develop. At this time, it's looking most likely that any severe threat will be over in eastern North Dakota into northwest Minnesota based on timing and diurnal instability. If that trend changes such that the front moves faster, that could put a little of our area (e.g. Brainerd Lakes towards International Falls) at a greater risk for seeing a few stronger storms. In general, we might have potential for up to 1.5 kJ/kg of MUCAPE and 30-40 kt 0-6 km shear which could promote a few strong to severe storms, but more likely is that this threat will be largely to our west and we will get the leftovers with some rain and general thunderstorms moving through Monday night. Strong winds and perhaps some hail will be the main threats if any stronger storms were to happen, but it's a pretty low (<10%) chance at this time.

Showers and storms will gradually continue east on Tuesday, lingering into the Arrowhead and northwest Wisconsin potentially. Cooler temperatures with highs in the 70s are expected on Tuesday following the front.

Wednesday through Friday: Another relatively cool and quiet day on Wednesday with highs likely in the 70s. Flow aloft is looking like it will become more quasi-zonal with several passing waves. We may have some more rain chances around Thursday into Thursday night, then perhaps again around Friday into Friday night.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 1258 PM CDT Fri Jul 31 2026

Main concern for this afternoon is rain out there mainly affecting BRD/HYR/DLH. Expect MVFR conditions. Some redeveloping thunderstorms are possible later this afternoon into this evening at DLH/HYR, so expect some varying visibilities with VFR and MVFR conditions at times. Winds will gradually become predominantly northwesterly at MN terminals, but more variable at HYR. Speeds should be pretty light overnight. There is a good signal for some fog, possibly dense, at DLH/HYR where most of the rain has been falling. Expect that there will be rapid fluctuations in visibility and possibly ceilings overnight with MVFR/IFR conditions at times. The fog will lift around the 12-13z window with VFR conditions at all terminals Saturday morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1258 PM CDT Fri Jul 31 2026

Light southwest winds will gradually switch over to northeast overnight. Speeds will increase into the afternoon with gusts expected to be from 15-20 kt and wave heights in the 1-2 ft range. We will have to keep an eye on these trends though, because it's possible that winds and waves could end up just a bit higher such that some small craft advisories may be warranted around the head of the lake (probability ~25%). A similar situation is expected on Sunday with high pressure over Lake Superior. Winds become more southerly inland on Monday, but remain more northeast on the water. We will probably again have 15-20 kt gusts with a small risk for seeing some gusts to 25 kt.

Showers and isolated thunderstorms are expected through this evening. Strong to severe storms are not expected.

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

FIRE WEATHER

Issued at 1258 PM CDT Fri Jul 31 2026

Rain continues for east-central Minnesota into northwest Wisconsin through this evening. Additional widespread amounts are expected to be light, less than a quarter inch, but several locations should pick up locally higher amounts with some heavier showers and possibly a few thunderstorms possible this evening in east-central Minnesota into northwest Wisconsin.

On Saturday, there's a ~20-30% chance for a few showers mainly around the Arrowhead during the afternoon. Rainfall amounts are expected to be light.

Otherwise, pretty quiet weather Saturday through Monday. Light north winds Saturday, southeast winds in northern MN Sunday with some gusts in the 20 mph range, and south winds with gusts around 15-25 mph Monday pretty much everywhere (best chances on the MN side though). While min RH values are generally expected to reach the 40-50% range, it wouldn't be surprising if there are some lower amounts due to lack of rainfall in northeast Minnesota. We will have to monitor trends and see what happens on Saturday, as this will be telling for Sunday and Monday's conditions, which will likely be similar.

A cold front Monday night will likely bring some rain and thunderstorms. There is potential for a wetting rain for many areas.

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.