textproduct: Duluth

KEY MESSAGES

- Hotter and sticky today and tomorrow with highs returning back into the mid to high 80s and dewpoints in the mid 60s to low 70s.

- Showers and thunderstorms possible this evening into early Tuesday morning. Isolated to scattered severe storms with large hail and damaging winds are possible for north-central Minnesota.

- Heavy rainfall with scattered flash flooding and isolated severe storms continues to look likely for portions of Minnesota and Wisconsin late Tuesday through the day Wednesday. Uncertainty remains high on the exact placement of the heaviest rain.

UPDATE

Issued at 247 AM CDT Mon Jul 6 2026

Southwest to northeast oriented upper level ridging pushes over the area today, leading to a calm weather day for most of the Northland until this evening. Ridging will allow heat and humidity to blossom into the Northland today and tomorrow. Afternoon highs rise into the mid to high 80s with dewpoints increasingly more widespread into the mid to high 60s. Tuesday could sport some dew points moving up into the low 70s. While no heat headlines are planned, expect it to be feel very muggy for the next two days. A low is expected to strengthen over Hudson Bay with a cold front draped down into the ND/MN border today, which should prompt storm development in the Red River Valley this afternoon along a plume of substantial instability and modest shear. This should push east, maintaining a Marginal to Slight severe storm risk into north-central MN. Storms could produce large hail and damaging winds. The best synoptic forcing is to the north of the International Border, which may lead to a situation where storms start to fizzle out fairly quickly through the late evening and early morning hours as the diurnally forced instability wanes.

That cold front as it passes over the area through the day Tuesday should 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. 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. There is still considerable uncertainty in exact placement of this front with model solutions still laying down the band of heavy rain anywhere from the Iron Range to the northern Twin Cities suburbs. The placement of the stalling cold front on Tuesday will likely be the biggest indicator of Wednesday stationary front placement, though a reservoir of the best instability further south could favor a slight pull towards the lower CWA border. Wherever that band does end up, a very moist airmass, skinny saturated CAPE profiles, deep warm cloud layers, and fairly slow winds/Corfidi vectors check all the boxes for flash flood development. Heavy rain of 2-4", locally up to 6-7" is possible. If the heaviest band set up from the Brainerd Lakes/Grand Rapids area to the Twin Ports and into NW WI that might be particularly concerning since 1) this area has seen some of the highest rainfall amounts in the last week and 2) it contains the most urban areas in our CWA which would be more predisposed for flash flooding due to the amounts of impervious surfaces. Once the area for the heaviest rain gains some forecast confidence, a Flood Watch will likely be needed. Some isolated severe storms capable of producing large hail and damaging winds are also possible along the southern and eastern edge of convection. Expect most of this precipitation to move out of the area by Thursday morning.

DISCUSSION

Issued at 1220 PM CDT Sun Jul 5 2026

High pressure and an upper level ridge are over the Northland today, providing a generally pleasant and quiet end to the holiday weekend. There is still a bit of lingering moisture and minor instability across the region, which could spark a few meandering, isolated rain showers or perhaps a stray non-severe thunderstorm this afternoon. Most folks will stay completely dry with light winds and comfortable humidity levels. Expect high temperatures to reach the upper 70s to lower 80s inland, while onshore northeast winds keep the immediate Lake Superior shoreline noticeably cooler. Tonight will feature mostly clear skies and quiet weather as high pressure drifts overhead.

Monday brings a noticeable shift in the airmass as southerly return flow pulls hot and humid conditions back into the area. High temperatures will surge well into the middle and upper 80s for a vast majority of the region. Most of the daylight hours will remain dry under plenty of sunshine. However, a cold front will begin to drop southward out of Canada by late afternoon and evening. As this front interacts with the hot and unstable airmass, scattered thunderstorms are expected to develop and track northwest to southeast across the area Monday evening into the overnight hours. A few of these storms could be strong to severe, packing a threat for damaging wind gusts and large hail.

The weather pattern becomes highly concerning for late Tuesday through the day Wednesday as the aforementioned cold front stalls out and becomes a stationary boundary draped directly across our region. We are closely monitoring this period for a heavy rainfall threat. The intense moisture pooling along the stalled boundary creates a highly favorable setup for training thunderstorms and scattered flash flooding. The Euro EFI (Extreme Forecast Index) signal for this timeframe has been trending upwards suggesting higher chances for a significant heavy rainfall event. The forecast ceiling (the maximum percentile from the NBM for this setup) for rainfall looks to be around 7 inches. While this represents what could happen over a small area, the mean gives a better idea of more widespread chances which are more than 1" for at least half of our forecast area. The most likely area for this is along a band from Brainerd to Moose Lake to Ashland. The northern side of this band will likely fade QPF quickly to its north leaving the Borderlands out of significant rainfall. Now, as the earlier discussion mentioned there is still a bit of uncertainty with the location of where the cold front stalls and turns into a stationary front. Upper level flow still looks favorable to pump moisture up and over the front somewhere in our forecast area Tuesday into Wednesday.

By Thursday, the heavy rain producing system will finally push east of the region, bringing a much needed reprieve from the oppressive humidity and unsettled weather. High pressure will build back in, allowing dewpoints to fall back into the more comfortable 50s and lower 60s. High temperatures will generally hover in the upper 70s to lower 80s for Thursday and Friday with plenty of sunshine and dry conditions expected. As we head into next weekend, upper level ridging will begin to amplify once again over the central United States, which will slowly start to dial the heat and humidity back up across the Northland.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 616 AM CDT Mon Jul 6 2026

VFR conditions expected through this afternoon. Winds become southerly through the morning. A cold front with attending showers and thunderstorms moves from northwest to southeast this evening and overnight into Tuesday morning, bringing a chance for showers and thunderstorms to INL, HIB, and BRD. Any precipitation chances at DLH and HYR are currently low, due to the precipitation being expected to fizzle out as the front moves east overnight.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 247 AM CDT Mon Jul 6 2026

A fairly calm day on Lake Superior is expected today 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 very late this evening into Tuesday morning, but confidence is low on if these thunderstorms will actually make it as far east as Lake Superior. Winds turn back to the northeast Wednesday. Expect potentially widespread rain showers and thunderstorms late Tuesday night into Wednesday with the best chance from the Twin Ports and east along the South Shore.

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

FIRE WEATHER

Issued at 247 AM CDT Mon Jul 6 2026

Southerly winds return today along with further warming temperatures. Some wind gusts of 15-20 mph are possible in north- central Minnesota this afternoon. We could see some afternoon and evening showers and thunderstorms moving from NW to SE along a cold front this evening into early Tuesday morning, with a couple isolated showers and thunderstorms possibly lingering through the day Tuesday. There is a chance that these showers and storms fizzle out before making it to Lake Superior and NW WI. An isolated storm could become severe this evening with large hail and damaging winds, with the best chance in north-central MN. There is an increasing signal for heavy rainfall late Tuesday through the day Wednesday. However, that heavy rain will likely have a sharp gradient on the north side, potentially leaving areas closer to the International Border mostly dry. Confidence is still low on exact placement however.

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.