textproduct: Duluth

KEY MESSAGES

- Strong to severe thunderstorms possible across north-central Minnesota later this afternoon and evening. Hail to around half dollar size, gusty winds, and a few tornadoes will be possible.

- Additional showers and thunderstorms will be possible Wednesday, mainly during the afternoon and early evening. Strong or severe storms are not currently expected, but funnel clouds and perhaps a brief, weak tornado cannot be ruled out.

- A more summer-like pattern sets up for the end of the week into early next week with increasing moisture and temperatures before chances for storms return Sunday into the new week.

DISCUSSION

Issued at 315 PM CDT Tue Jun 23 2026

High pressure was located over the Mid-Mississippi Valley early this afternoon with an area of low pressure south of Lake Manitoba just north of the International Border. A cold front trailed across the eastern Dakotas into Nebraska with a short warm front extending southeastward into southeast Minnesota. An area of showers and thunderstorms extending from the Twin Ports area back into central Minnesota. Some clearing was observed on satellite behind this area of rainfall across northwestern Minnesota. This will help build some instability ahead of the cold front to around 700-800 J/kg in north-central Minnesota. Effective shear looks to increase to 35 to 40 knots, which will be supportive of a few supercells along with clusters of storms. Mid-level lapse rates look pretty marginal, but any discrete storm that can develop a mesocyclone will have the potential to produce hail to the size of half dollars or ping pong balls. DCAPE will only be around 500-600 J/kg, so not as high of a damaging wind threat, but there are winds 70-80 knots aloft that could be mixed down. Any storm that crosses the warm front will have the potential to become tornadic, especially if storms ride along the front. The greatest threat for severe weather this afternoon and evening will be mainly across northwestern Minnesota into central Minnesota. In the Northland, this would be south of a Cass Lake to Brainerd line for any tornado threat with the hail and gusty winds being possible west of a Ash Lake to McGregor to Isle line.

Showers and embedded thunderstorms will remain possible overnight and into Wednesday as the area of low pressure moved through the region. This will be more akin to a fall system being cold core. Would not be surprised if a few funnel clouds or even a weak tornado occurred Wednesday, especially in the vicinity of the low. Rainfall tapers off Wednesday night as the low moves to the southeast and high pressure builds in across the Upper Midwest. Dry conditions are expected to prevail for Thursday and most of Friday with southerly return flow bringing near normal temperatures in the 70s along with increasing moisture. A weak shortwave may pass through late Friday and could lead to a few showers and thunderstorms.

An upper ridge moves through the Upper Midwest for Saturday into Sunday with warmer temperatures reaching into the 70s and 80s with ever increasing moisture. Models have diverged for the end of the weekend and into early next week. While there will be increased chances for storminess as the upper ridge moves to the east, timing and locations of the waves on the west side of the ridge remain nebulous. Given the heat, increasing moisture, and more of a summer pattern, strong to severe storms will be possible somewhere from the Northern Plains into the Upper Midwest heading into next week. PWATs look to reach 1.5" plus during this time, which would be above the 90th percentile for late June. This may lead to heavy rainfall at times, which is certainly needed given the increasing drought conditions in the region.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 623 PM CDT Tue Jun 23 2026

Widely scattered to isolated showers and storms are present along an occluded front in west-central Minnesota and slowly moving east into this evening. A couple of these storms may become strong to severe in north-central MN/BRD vicinity but potential is low. Large hail and erratic thunderstorm gusts would be the main threats along with the potential for MVFR to IFR conditions if a storm moves directly overhead. Shower coverage decreases with eastward extent later this evening into tonight, with thunderstorm potential also decreasing, so tried to time out peak potential overnight, but high-resolution models are poorly handling this activity. As an area of low pressure moves in tonight into early Wednesday morning, expect MVFR to IFR ceilings with pockets of IFR or lower fog, with the best potential at DLH and HYR. , this will bring MVFR to IFR ceilings along with areas of IFR or lower fog. Conditions gradually improve Wednesday morning, but ceilings should still be near the MVFR/VFR threshold in the late morning and afternoon as scattered diurnal showers and storms develop on Wednesday.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 315 PM CDT Tue Jun 23 2026

Easterly winds of 5 to 15 knots will continue this afternoon and into this evening. A few gusts to around 20 knots will be possible near the Twin Ports for a few hours late this afternoon and early evening. Winds will remain easterly for Wednesday at 5 to 15 knots with gusts to around 20 knots along the North Shore. Winds will diminish to around 5 to 10 knots Wednesday night. High pressure brings variable winds at 10 knots or less for Thursday before turning easterly for Friday at 5 to 15 knots, strongest near the Twin Ports.

Showers and a few thunderstorms will be possible late this afternoon through Wednesday afternoon. No strong or severe storms are currently expected, but gusty and erratic winds, small hail, and heavy downpours will be possible along with cloud-to-water lightning.

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

FIRE WEATHER

Issued at 315 PM CDT Tue Jun 23 2026

Showers and thunderstorms will move across the region this afternoon and tonight with activity lingering for Wednesday, although with less coverage. Rainfall amounts will vary depending on where storms move with amounts in the 0.10 to 0.40 inch range through tomorrow evening. Isolated higher amounts to 0.50 to 0.75 inches will be possible in any stronger storms. With abundant cloud cover and periods of rainfall tomorrow, afternoon RH values will remain well above 50%. Drier conditions arrive for Thursday and Friday with afternoon RH values falling to around 40 to 45 percent with isolated areas as low as 35 percent, mainly in the Arrowhead. Winds will remain under 20 mph through the rest of the week outside of any storms.

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.