textproduct: Duluth

KEY MESSAGES

- Light to moderate rain is likely tonight into early Sunday morning.

- Widespread rain Sunday night through Monday night, ending on Tuesday. Rainfall amounts around or over one inch are possible for many areas. Expect some non-severe thunderstorms Monday and Monday evening for southern portions of the Northland. Some minor areal and river/stream flooding is possible. - Temperatures will trend slightly below average for Tuesday through the end of this coming work week.

DISCUSSION

Issued at 236 PM CDT Sat Apr 25 2026

Rest of Today - Sunday:

A weak cold front has moved into NE MN with cloud cover gradually increasing across the area. Model soundings and surface observations show stubborn low-level dry air across much of the Northland, which is resulting in much of the precipitation appearing on radar evaporating before it reaches the ground. The exception is central MN and locations back into SW MN which is in the better ribbon of moisture at the moment. As we progress into this evening and tonight, shortwave energy will interact with the cold front that will become a stationary boundary and bring light rain/pockets of moderate rain to the Northland, lingering into Sunday morning, though patchy rain shower chances may linger at times through daytime Sunday. Instability remains very low to zero with this rain, so while a few rumbles of thunder can't be ruled out tonight, they should be few and far between at best. Rain amounts have trended slightly upwards, with 0.25-0.5" forecast for the Brainerd Lakes, I-35 corridor, and into the MN Arrowhead. Amounts taper off to 0.1" or less in far north-central MN and east of the St. Croix River valley in NW WI outside of the main rain band.

Far northern St. Louis County down into the I-35 corridor has seen drier relative humidities develop this afternoon before the more prominent cloud cover moves in, with relative humidity as low as the 23-30% range. Other locations in the Northland have remained slightly less dry. With wind gusts generally 15 mph or less in these drier areas, near-critical fire weather conditions remain limited in scope.

Easterly winds and a lake breeze off of Lake Superior and lingering cloud cover many portions of the Northland on Sunday should tamper down high temperatures to the mid/upper-40s near Lake Superior to low/mid-50s farther inland. Only portions of inland NW WI and Koochiching County appear to have high temperatures touch 60 to the lower 60s where cloud cover will be less and the lake breeze doesn't reach. Portions of far north- central Minnesota could see afternoon relative humidity dip down to around 25-30%, so we will need to watch that area for near- critical fire weather potential despite lighter winds.

Sunday Evening - Tuesday:

Lee cyclogenesis will develop a Colorado Low late Sunday will quickly move northeast and strengthen, tracking northeast through Iowa/southern MN by midday Monday, north-central/NW WI by Monday evening, and exiting into Ontario daytime Tuesday. This track has trended slightly farther southeast over the past 24 hours. This system will bring a surge of moisture with origins in the western Gulf and modified moisture from Baja California. Latest NAEFS PWAT percentiles still reach the 90th percentile (around 0.8-1.2" of PWATs) for Monday through Monday night for much of the Northland, highest near the surface low center track in NW WI. Broad support for parcel ascent with good synoptic forcing should aid in development of rain with this system as it moves through the region starting Sunday evening in north-central MN, becoming more widespread Sunday night into Monday, and ending SW to NE Tuesday morning as the low pressure system exits. Some non-severe thunderstorm activity is also possible Monday afternoon and evening from the Brainerd Lakes to Twin Ports and areas southeast. The southeast trend in the surface low pressure track should keep the primary warm sector of this system and attendant severe storm threat south of the area, with most of the Northland seeing this rainfall as more stratiform in nature for much of the event.

While rain rates could be higher for a time Monday afternoon and evening with any thunderstorms, mostly stratiform rain should keep rates on the more moderate side. However, given the prolonged timeframe of rainfall, saturated soils, and elevated river/streamflows from previous rainfall and snowmelt in the eastern Rainy River Basin and the North Shore/South Shore rivers, additional rainfall from this system could produce some minor areal and stream/river flooding. Rainfall probabilities are 60-90% across the Northland for at least 1" with this system, with probabilities of >2" at 10-30% in the Brainerd Lakes, St. Croix River Valley, and North Shore, and less elsewhere. Overall, a more widespread soaking rain for many locations.

Mid - Late Next Week:

A slightly cooler and generally drier northwest flow pattern aloft sets up mid to late next week. While there will be periodic shortwave energy aloft in this pattern, moisture availability is generally lacking. Therefore, we have kept periodic precipitation chances at 20% or less for Wednesday through next Saturday. The Tuesday through Friday timeframe will also be slightly below average with daily highs in the upper 40s to 50s (warmest south) and lows around or just below freezing. Surface temperatures do appear to trend up a bit starting next Saturday as the pool of colder 850 mb temperatures exits east of our area.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1248 PM CDT Sat Apr 25 2026

VFR ceilings under increasing cloud cover and primarily light winds are expected today through early evening. INL will occasionally see gusts to 15-20 kt this afternoon before winds turn light and variable tonight into Sunday morning. Some pockets of light rain are possible at times this afternoon at BRD and HIB, but precipitation will be fighting low-level dry air until this evening. Then, rain coverage ramps up this evening from southwest to northeast. The main corridor of rainfall will be from BRD/DLH/HIB and into the Minnesota Arrowhead. Expect ceilings and visibilities to initially be VFR as rain moves in, but then drop to MVFR tonight for those terminals tonight into early Sunday morning. DLH could also see IFR ceilings tonight given a combination of rain and Lake Superior influence. INL should remain VFR through the period with rain chances primarily to the southeast. HYR will see some rain at times tonight into Sunday morning with MVFR ceilings and perhaps brief periods of MVFR visibilities.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 236 PM CDT Sat Apr 25 2026

Light northeast winds are expected through early Sunday. However, winds begin to pick up starting Sunday afternoon, and moreso Sunday night and Monday when a large low pressure system passes through the region. With northeast winds funneling down the southwest arm of Lake Superior Sunday evening, gusts could approach or exceed 20 kt and produce 2-4 ft waves. Small Craft Advisories may be needed if this were to occur. Otherwise, more widespread hazardous conditions for small craft are likely with the stronger winds arriving Sunday night into Tuesday. As winds turn northwesterly late Monday night into Tuesday, there is a 30-40% chance for gales along the North Shore. Expect rain and a few thunderstorms in this period as well, with non-severe thunderstorm potential mainly Monday afternoon and evening. Winds turn largely light for Wednesday through the end of the coming week.

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

FIRE WEATHER

Issued at 236 PM CDT Sat Apr 25 2026

Fairly dry day out there with generally light winds for most. Min afternoon RH has dipped into the 23-30% range for St. Louis County down into the St. Croix River Valley where cloud cover has been slower to fill in. However, wind gusts in these areas are less than 20 mph, so the near-critical fire weather threat has remained fairly limited in scope. Elsewhere, afternoon RH bottoms out in the 30-40% range. Cloud cover increases the rest of today into early Sunday along with increasing rainfall potential from southwest to northeast starting mainly this evening and continuing into Sunday morning. Precipitation amounts of 0.25-0.5" are forecast from the Brainerd Lakes northeast into the Arrowhead, with amounts falling off to 0.10" or less in far north-central MN and east of the St. Croix River Valley.

Mostly light east winds will bring broad onshore flow from Lake Superior on Sunday, with lingering clouds for most locations. Pockets of light showers/sprinkles may also linger daytime Sunday. This will keep temperatures cooler for much of the Northland, though far north-central MN could see some clearing from clouds and see afternoon RH drop to 20-30%, lowest in Koochiching County. While winds will be lighter where RH is lowest, the low min RH values could create near-critical fire weather conditions. Elsewhere, min RH largely remains above 40%.

Widespread rain is Sunday night through Monday night, then ends from southwest to northeast Tuesday morning. Fire weather conditions are expected to be limited as a result. Some thunder is possible at times with the rain Monday and Monday evening.

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.