textproduct: Duluth

KEY MESSAGES

- Another dry day but less windy then yesterday.

- Warm Wednesday with highs climbing into the 70s. Cooler by the lake.

- Rain and storm chances return late Wednesday and through Thursday. Some storms may be strong to severe.

DISCUSSION

Issued at 239 AM CDT Tue Apr 21 2026

Current Conditions/Today:

Quiet today with sunny skies across the region. Surface high pressure moving across northern MN and into Ontario will keep winds much calmer then what we saw yesterday. Still looking at dry conditions and with the lack of cloud cover we should see even more efficient mixing than what we saw yesterday. Min RHs are expected to fall to less then 20% across the region. Fortunately the lack of wind will help to mitigate the fire weather risk.

Wednesday:

High pressure gets shunted off to the east as a deep trough digs into the Central Rockies. Southerly flow ramps up across the region promoting warm air advection. Highs are expected to soar into the 70s away from Lake Superior with a few 80s possible. Northeasterly winds off of Lake Superior will likely induce a Lake breeze, however the background southerly winds should keep this breeze from penetrating too far inland. A strong surface low develops in the Northern Plains that will swing a warm front across the Northland Wednesday evening. Pairing with a low level jet surging in from the south we will see building MUCAPE with some isentropic lifting for ascent that could produce some showers and isolated thunderstorms. The lack of deep layer shear will keep storms from getting out of hand overnight.

Thursday/Friday:

The Northern Plains low strengthens on Thursday as an upper level jet rounds the base of the trough and ejects over the Northland. The Northland will find itself in the warm sector of the approaching system setting up a gulf connection. With dewpoints rising once again we will see a response in instability as well. Surface based convection looks like it will be hard to come by in the current set up with a stout warm nose in the low levels. The cold front associated with this system does not appear to move in from the west until the the evening hours which will coincide with the better bulk shear values. Early assessments would suggest that we could see some isolated thunderstorm potential developing in the afternoon, but the main activity will initiate off to our west and propagate into our region in the evening hours. Still a little too early to tell how well the environment will hold up to support these storms Thursday night. The current CSU machine learning and AI models are still hinting at some severe potential, although the higher probabilities remain to our west and south.

On Friday the low pressure system is projected to retrograde and stall out over southern Manitoba. Strong ridging over the Atlantic looks to hold this feature in place through most of the weekend. Could still see some lingering shower and storm activity as its occluded boundary moves east into Ontario. The proximity of the low will see temperatures regulate back into the 50s Friday and through the weekend.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1234 PM CDT Tue Apr 21 2026

VFR conditions expected through the period as a very dry airmass lingers over the region. Northerly winds today become light and variable overnight, veering to the southeast close to daybreak on Wednesday. Breezy southerly winds will be possible tomorrow, especially in the Brainerd Lakes towards the Iron Range.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 239 AM CDT Tue Apr 21 2026

Surface high pressure moving across northern MN will keep winds light today. Winds will increase a bit on Wednesday out of the east around 10 to 15 knots. The next period for potential hazardous conditions for small vessels is Thursday as southerly flow will lead to building waves on the North Shore. There will also be potential for showers and storms on Thursday.

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

FIRE WEATHER

Issued at 239 AM CDT Tue Apr 21 2026

Surface high pressure will be moving across northern MN today providing light winds and sunny skies. Better mixing is expected today with Min RHs expected to drop to 15-20%. High pressure will move off to the east on Wednesday with southerly flow returning to the region. We could still see some low RHs on Wednesday once again despite the return flow being slightly more moist. Min RHs at this time look to be more in the 20-25% range with southerly winds gradually increasing through the day. By the afternoon we expect to see wind gusts of around 20 mph.

Active weather returns Thursday with showers and storms back on menu. Some storms may be strong to severe.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Fire Weather Watch from Wednesday afternoon through Wednesday evening for MNZ018-025-026-033>036. WI...None. MARINE...None.