textproduct: Duluth

KEY MESSAGES

- Dry RH and gusty winds will create critical to near-critical fire weather conditions Monday. A Red Flag Warning is in effect for most of northeast Minnesota (except southern Lake and Cook counties).

- Warmer temperatures return through mid week with dry conditions through Wednesday.

- Active weather will bring precipitation chances Thursday and Friday with thunderstorms possible Thursday evening. Cooler temperatures are expected for next weekend.

UPDATE

Issued at 323 AM CDT Mon Apr 20 2026

Early this morning, surface high pressure is centered over the region, leading to clear skies and chilly temperatures in the teens and 20s. As the high shifts east today, southerly winds will strengthen significantly. A low pressure system will move from far northern Manitoba east to Hudson Bay, dragging a dry cold front across the region this evening and overnight. Ahead of that front, warm, dry and windy conditions are expected to develop. The combination of dry air and gusty southwest winds will lead to critical fire weather concerns for most of northeast Minnesota. Relative humidity values there are expected to drop into the 20 to 30 percent range, with southwest wind gusts of 20 to 30 mph. The Fire Weather Watch which was issued yesterday has been upgraded to a Red Flag Warning, adding on northern Lake and Cook counties.

Tonight, the aforementioned dry cold front will move through the region, shifting winds to the west and northwest. While clouds will increase with the frontal passage, no precipitation is expected. Low temperatures will be notably milder than previous nights, staying in the upper 20s to mid 30s. Tuesday will be dry once again, but with much lighter northerly winds, fire weather concerns are much lower than today.

For the remainder of the forecast, it has not changed much from the day shift. The latter half of the work week looks active with warmer than normal temperatures through Thursday, precipitation chances Thursday and Friday and then cooler temperatures for the weekend.

DISCUSSION

Issued at 218 PM CDT Sun Apr 19 2026

Tonight:

Surface high pressure is pushing across southern Manitoba this afternoon, moving toward the Northland. North to northwest winds remain gusty this afternoon, with a scattering of fair weather CU across the skies. The high will quickly cross the area tonight, maintaining mostly clear skies and diminishing winds. With dewpoints in the teens and single digits, expect lows overnight to fall into the teens to mid 20s.

Monday:

A storm system wil move across northern Manitoba and Ontario Monday, dragging a cold front into the Northland Monday evening. Ahead of this system, south to southwest winds will increase, with gusts of 25-30 mph by mid morning in the west and spreading across most of the Northland through the day. This will lead to increased fire weather concerns as model soundings show a significant dry air in the lower levels. Expect good mixing conditions, with dewpoints in the low to mid teens, coinciding with the increasing winds. Min RH values will fall below 25% across much of the Northland, with the longest duration of both low RHs and strong winds west of the Hwy 53 corridor. The one limiting factor could be cloud cover associated with the front moving into the area. Those could limit heating and mixing. See the Fire Weather Discussion for details on headlines.

Tuesday/Wednesday:

Quiet conditions for both Tuesday and Wednesday as surface high pressure moves across the region. High temps start in the upper 50s to 60s on Tuesday and climb into the upper 60s and 70s for Wednesday. Areas near the Lake remain in the 50s.

Thursday/Friday:

An upper level trough will cross the Rockies mid week, sending a surface low and frontal system across the Plains Wednesday into Thursday. Ahead of this system, strong southerly winds will pump Gulf moisture northward through the Mississippi River Valley and into the Northland. Guidance is fairly agreeable on timing of a warm front lifting through the area Wednesday night, opening the door to a quality warm sector and increasing instabilities by Thursday afternoon. Combined with strong upper and low level jets ahead of a cold front arriving Friday evening, severe storms could be possible. Will need to assess details over the next couple days (like a cap and cloud cover limiting afternoon heating).

Guidance is in better agreement for the end of the week, with both model suites leaning toward a stacked system rotating over Ontario through at least Saturday, maybe longer. This could keep periods of rain in the forecast. For now the NBM maintains 20-30% PoPs through Saturday.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 600 AM CDT Mon Apr 20 2026

VFR conditions are forecast through the period. Winds are light this morning as high pressure passes overhead. Winds will become southerly and increase during the daytime today, with gusts of up to 25 knots for the afternoon hours. A cold front will move into the region this evening after 21.00Z which will veer winds westerly, then northwesterly. Ahead of the front, strong southwesterly winds aloft as surface winds decrease will cause LLWS to develop for KDLH and KHYR for the overnight hours.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 317 AM CDT Mon Apr 20 2026

Southwest winds increase to 15-20 knots with gusts to 25 knots for portions of the nearshore waters this afternoon. A Small Craft Advisory is in effect for around the Twin Ports, Saxon Harbor and Chequamegon Bay, and along the North Shore from Grand Marais to Grand Portage. Waves will build to 2 to 4 feet along the North Shore and 1 to 3 feet elsewhere. Winds will shift to the northwest and diminish by Tuesday morning, then remain less than 10 knots through Tuesday night.

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

FIRE WEATHER

Issued at 317 AM CDT Mon Apr 20 2026

A Red Flag Warning has been issued for most of northeast Minnesota as relative humidity drops to 20-30 percent and south winds gust to 30 mph. A low pressure system will track well to our north, but bring increased south to southwest winds. Cloud cover remains the main concern as some models are suggesting decent coverage through the day that would reduce heating and drying. The most likely areas to clear would be across our west where Min RHs drop below 25% for most of the afternoon. If we do get a fair amount of sunshine we could see these fall to below 20%. Conditions along the North Shore do not look quite as dry, with min RH values only dropping below 30% for just a couple hours. The southwest winds will be weaker there as well.

Tuesday remains dry with minimum humidity near 25 percent, but lighter north winds will reduce the fire weather concerns.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Red Flag Warning from 11 AM this morning to 8 PM CDT this evening for MNZ010>012-018-019-025-026-033>038. WI...None. MARINE...Small Craft Advisory from 2 PM this afternoon to 8 PM CDT this evening for LSZ121-144-145-148. Small Craft Advisory from noon today to 10 PM CDT this evening for LSZ140.