textproduct: Duluth

KEY MESSAGES

- Isolated rain showers and thunderstorms are possible today, otherwise expect a calm, slightly warmer July day.

- Warming up for Monday and Tuesday with a chance of showers and thunderstorms, possibly severe, Monday evening.

- Increasingly favorable setup for heavy rainfall somewhere in the Northland late Tuesday through the day Wednesday. Scattered flood flooding is possible with some isolated severe storms.

UPDATE

Issued at 303 AM CDT Sun Jul 5 2026

Upper level ridging continues to nose into the Upper Midwest today which should make for a partly cloudy day with light winds as high pressure becomes the more dominant theme. We do still have some lingering moisture and minor instability hanging around today, which could prompt some meandering scattered rain showers, and possibly a non-severe thunderstorm or two for the I-35 corridor into NW WI this afternoon.

Most of Monday's sensible weather will likely be controlled by that nose of upper level ridging as we see temperatures rising back into the mid to highs 80s with southerly winds. However, at the same time a low is expected to strengthen over Hudson Bay with a cold front draped down into northern Minnesota which could develop precipitation in NW MN Monday PM which may then propagate eastward across the Northland. The best synoptic forcing is to the north of the International Border, which does lend some uncertainty to the situation thanks to mid-level capping to the south that could limit precipitation development. Should storms be able to fire however, substantial instability and modest shear could help prompt a couple isolated severe storms capable of producing damaging winds and large hail.

That cold front as it passes over the area through the day Tuesday looks to help lay the groundwork for the next disturbance as the aforementioned ridging shifts a little more east and shortwave disturbances continue to propagate through the westerly flow over the Northern Plains. Pattern recognition suggests an overall Maddox Frontal Pattern sets up late Tuesday through the day Wednesday as the cold front morphs into a west to east oriented stationary one somewhere across MN-WI-Upper Michigan. A very moist airmass, deep warm cloud layers, and fairly slow winds/Corfidi vectors should add up to producing an area of potentially very heavy rainfall. However, the placement of that rain could be semi dependent on the leading disturbances in the day before and model guidance places it anywhere from the International Border to the Twin Cities. Where it does end up, localized heavy rain in excess of 3-4" with scattered flash flooding and isolated severe storms could be possible. Wednesday will be a day to keep an eye on as it gets closer.

DISCUSSION

Issued at 1119 AM CDT Sat Jul 4 2026

Happy Fourth of July to the Northland. The main focus for today will be shower and thunderstorm chances. Outflow boundaries will be the trigger mechanisms for storms today. Because of this, we have upped PoPs to have a minimum of 20 percent across the Northland given the nature of the environment. A few of these storms could become strong to severe, with damaging wind gusts up to 60 mph, hail up to quarter size, and heavy downpours that could lead to localized flooding. The best environment for stronger storms is across north-central Minnesota where buoyancy is highest while a local minima exists in the Arrowhead east of Silver Bay. We could also see some appreciable rainfall amounts out of these storms, with the HREF max and LPMM products suggesting very localized totals of 3"+, location dependent on exactly where storms fire. Many model solutions however are suggesting that some of the highest precipitation totals could be in the Itasca/Cass/Aitkin county to I-35 and Twin Ports area, which is where some of the highest localized rainfall totals have been recently. If heavy rains fall in the right area, some localized flooding could be possible. The primary timing for widespread storms and any severe risk should be between 3-10 PM. Thinking about 30% of folks will have their evening activities impacted by these thunderstorms.

Aside from the storms, it will be a cooler day near Lake Superior with gusty northeast winds keeping highs in the 60s, while inland areas reach the 70s and low 80s.

Heading into Sunday, the upper level disturbance that is bringing us today's active weather will slowly push eastward. We could see a few lingering showers or a rumble of thunder, primarily across northwest Wisconsin, but severe weather is not anticipated. Much of the area will enjoy a mostly sunny and slightly warmer day to finish the holiday weekend, with high temperatures rebounding into the 70s to lower 80s. The northeast winds off Lake Superior will also gradually subside throughout the day.

High pressure briefly builds across the region on Monday, bringing a return to hot and humid conditions. High temperatures will climb well into the middle and upper 80s for a vast majority of the area. Most of the daylight hours on Monday should remain dry under plenty of sunshine, but we are monitoring the approach of another weather system that will bring precipitation chances back to the region by late Monday night.

The extended forecast for Tuesday through Friday looks active as a stationary frontal boundary sets up shop across the Upper Midwest. This will bring multiple rounds of showers and thunderstorms to our region, particularly peaking in coverage between Tuesday and Wednesday. Rich PWATs of 2" will linger around this boundary giving a heavy rainfall and flooding threat which is emphasized by the WPC's Slight Risk for Flash Flooding on Day 5. Totally warranted with upper level flow parallel to this low level boundary allowing for elevated potential for training storms along the stationary boundary. Euro EFI does hint at a SOT of > 1 for this time period though still a bit of uncertainty at where this boundary sets up and if ingredients align. As of now, it looks like a good setup for heavy rainfall. High temperatures will generally remain in the 80s through midweek before slowly tapering back into the 70s by Thursday and Friday behind the departing system.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 555 AM CDT Sun Jul 5 2026

Largely VFR conditions expected through the period, outside of some pockets of fog that should burn off quickly in the next hour or so. There is a slight chance HYR could see a stray rain shower or thunderstorm this afternoon. Winds stay mostly light through today.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 303 AM CDT Sun Jul 5 2026

Northeasterly winds continue today but shouldn't be as strong as yesterday. Any fog that develops early this morning should burn off fairly quickly through the mid to late morning. Some areas, most likely in the Twin Ports, could see some afternoon gusts up to 15 knots. Tomorrow, forecast guidance has shifted, suggesting a very calm day on Lake Superior with an afternoon light onshore lake breeze circulation developing. West to southwesterly winds should arrive to Western Lake Superior into Tuesday with some stronger gusts up to 15 knots possible between Grand Portage and Isle Royale. Next best chance for showers and thunderstorms arrives across Western Lake Superior Monday evening.

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

FIRE WEATHER

Issued at 303 AM CDT Sun Jul 5 2026

A few isolated rain showers are possible at times today, but otherwise it should be fairly calm with partly cloudy skies. Some drier air is possible, especially in the MN Arrowhead where afternoon RH could drop down to around 35%. Southerly winds return Monday along with further warming temperatures. We could see some afternoon and evening showers and thunderstorms moving from NW to SE along a cold front Monday evening into early Tuesday morning, with a couple isolated showers and thunderstorms possibly lingering through the day Tuesday. An isolated storm could become severe Monday evening. Additionally, there is an increasing signal for heavy rainfall late Tuesday through the day Wednesday.

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.