textproduct: Duluth

KEY MESSAGES

- Another night with showers and storms possible. Severe risk has decreased and is now isolated to southeast portions of our CWA. Primary threats would be damaging winds and large hail.

- Freeze Warning likely needed across most the region for Tuesday night.

- Cool temps through midweek with a warming trend into the weekend.

DISCUSSION

Issued at 155 PM CDT Mon May 18 2026

Current Conditions/Today:

Widespread stratus has engulfed most the region in the wake of last nights showers and isolated storms. We are also seeing some areas of fog from the Brainerd Lakes Region and extending northeast through the Twin Ports and up the shore. This layer of stable air will keep temperatures cool with highs staying in the 50s under this cloud deck. Satellite is showing a few pockets of clearing over SE MN and western WI where temperatures will rebound back into the 70s helping to reload instability for this evenings convective potential. However, up in our portion of NW WI there are few breaks in the clouds with low clouds still filtering in from the west, so recovery seems limited.

A baroclinic zone will still be draped across the Upper Midwest this afternoon with a surface low pressure centered over SE MN. Through the evening and overnight hours several low pressure systems will ride along this boundary boosting lift and helping to fuel shower and storm development. However, satellite trends through the morning hours have not been favorable for instability recovery and our temperatures across the region remain quite cool when compared to our neighbors to the south. The main threat for severe weather will be well off to our south. As such the SPC has pulled the severe risk down to just our SE corner with a marginal risk. Some strong storms can't be ruled out at this time with some damaging winds and hail at times, but the tornado chances are no longer a concern.

Showers are expected to become more widespread later this evening. The two focal points for this activity is the low pressure moving along the stalled boundary and an upper level trough pivoting across the Upper Midwest. Targeted timing for rain entering from the southwest is after 9PM with activity departing to the northeast after 8AM. With the reduced risk for thunderstorms our overall rain totals have come down a bit with most the region seeing between 0.10-0.25" Areas that do see thunderstorms will have locally higher amounts, but the overall risk for flooding has diminished.

Tuesday/Wednesday/Thursday:

Northwest flow and surface high pressure builds in from the west on Tuesday. Cyclonic flow aloft paired with remnant moisture will lead to diurnally driven cumulus and isolated sprinkles across northern MN. Temperatures will be on the cool side for Tuesday with highs in the 40s and 50s. Overnight, the high pressure moves over MN with clear skies leading to rapid radiational cooling. Widespread Freeze Warnings will likely be needed across the region. Conditions dry out a bit more on Wednesday with high temps rebounding back into the 50s and 60s. Winds will be light so fire weather concerns are low at this time. By Thursday high pressure departs to the east and we will get southerly return flow streaming back into the region. High temps will continue to climb back into the upper 60s with cooler conditions expected by Lake Superior.

Friday-Weekend:

An upper level trough is still expected to move across the Northern Plains to end the work week bringing rain chances back to the Northland. Timing of this has been slowed down when compared to previous model runs with 20-30% PoPs now entering Friday afternoon. This will also prompt the return of southwest flow aloft leading to a warming trend. Weekend temperatures in the 70s and some 80s possible with cooler by the Lake still in play.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1223 PM CDT Mon May 18 2026

Widespread IFR/LIFR stratus clouds engulf most of the region this afternoon with a surface low over SE MN. Ceilings are not expected to improve through the day as a baroclinic zone is laid across the Upper Midwest. Later this evening showers and some storms are expected to develop and move northeast through the region. This activity will move off to the northeast tomorrow morning with gusty northwest winds filtering in behind. Ceilings may be slow to improve tomorrow.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 155 PM CDT Mon May 18 2026

Light winds currently across the Lake. These winds will increase out of the northeast this evening with Small Craft Advisories in effect. Winds will turn to out of the northwest Tuesday afternoon and weaken. Additionally, a few showers and storms are possible tonight through tomorrow morning.

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

FIRE WEATHER

Issued at 155 PM CDT Mon May 18 2026

Cloudy today with high Min RHs. Another batch of showers and a few storms are expected to roll over the region the region tonight and exit tomorrow morning. Rain totals have trended down with most areas expected to see between 0.10-0.25" Areas that do get thunderstorm development can expect locally higher amounts. Gusty northwest wind for Tuesday paired with virga and sprinkles in the afternoon. Next dry day will likely be Wednesday, winds will be light though as high pressure moves over the region.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Small Craft Advisory from 9 PM this evening to 1 PM CDT Tuesday for LSZ140>143. Small Craft Advisory from 11 PM this evening to 9 AM CDT Tuesday for LSZ144-145. Small Craft Advisory from 11 PM this evening to 11 AM CDT Tuesday for LSZ146-147. Small Craft Advisory from 9 PM this evening to 3 PM CDT Tuesday for LSZ148-150.