textproduct: Duluth

KEY MESSAGES

- Dry through this morning, then rain expands northward into the Northland starting this afternoon and evening.

- Several rounds of rain and thunderstorms are expected tonight through Wednesday. Some locations may see 1-2"+ of rainfall in that period, with highest potential in northwest Wisconsin. Minor flooding is possible, mainly along the South Shore and possibly the Arrowhead of Minnesota where deeper snowpack remain.

- Isolated strong to marginally severe storms are possible in northwest Wisconsin tonight. Large hail would be the main threat.

- Additional isolated strong to severe thunderstorms are possible Sunday and Monday afternoon/evening. Large hail and gusty winds are the main threats. Northwest Wisconsin will have the best chance for seeing any strong to severe storms.

UPDATE

Issued at 325 AM CDT Sat Apr 11 2026

Now through Midday Today:

Predominately clear skies early this morning due to high pressure centered over the western Great Lakes region. Expect lows around sunrise to bottom out in the 20s to around 30F across the Northland. This will likely be the last widespread below-freezing night until late this coming week due to a prolonged period of warmer air moving into the Upper Midwest. Cloud cover and temperatures will rapidly increase from south to north throughout the morning into early afternoon hours as increasing southeasterly winds and a plume of increasing moisture move in from the south.

Several rounds of showers and thunderstorms are expected starting this afternoon and continuing through Tuesday night/Wednesday. Details on each round are described below.

This Afternoon - Sunday Morning:

As the high pressure continues to depart to our east, a prominent tongue of moisture with Gulf origins will push into the Upper Midwest by this afternoon/evening and linger into Sunday, with PWATs approaching up to 1" in NE MN and to around 1.25" in NW WI. The atmosphere will initially be drier, so it'll take some time today for it to saturate up. Eventually, starting this afternoon expanding into tonight, strong isentropic upglide will develop elevated showers for this afternoon, and increasing embedded thunderstorm activity this evening into tonight as steeper mid-level lapse rates and elevated instability move overhead. Rain rates this afternoon should be on the lighter side, but pick up with the thunderstorm activity tonight into Sunday morning. Rain amounts with this initial round peak in the 0.3-0.75" range in NW WI, with decreasing amounts with northwest extent into NE MN and even less towards north-central MN. As is the nature with thunderstorms, localized higher and lower amounts are likely depending on where exactly the thunderstorms track. There is also a low-end potential (Level 1 of 5) for isolated strong to severe thunderstorms tonight along and south of a Spooner to Park Falls line in NW WI as deep layer shear of 30-35 kt, steep mid-level lapse rates, and MUCAPE of around 1000 J/kg would be sufficient for isolated organized thunderstorms with the potential for large hail up to the size of quarters.

Most high-res guidance shows shower/storm coverage decreasing from SW to NE across much of the Northland for Sunday morning into midday as the warm front surges north, setting the stage for the next round of shower and thunderstorm potential for Sunday afternoon and evening.

Sunday Afternoon - Sunday Night:

There are a couple areas of conditional strong to severe thunderstorm threats in the Sunday afternoon to Sunday evening timeframe. The first would be with and ahead of the cold front in the warm sector. By the time the surface capping inversion due to daytime heating would possibly break in the late afternoon/early evening, the cold front would already be impinging on the I-35 corridor and continue tracking eastward through NW WI through the mid-evening hours, so the window of time for severe potential in this area would be limited to about 4-6 hours. The better upper-level forcing associated with the mid/upper-level troughs are also farther northwest and may move through too quickly to kick off convection along and ahead of the cold front. However, if the forcing can line up with capping inversion breaking in the late afternoon into mid-evening, then the atmosphere would be primed enough with 1000-1500 J/kg of SBCAPE, 30-40 kt of 0-6km bulk shear, 7-7.5 deg/km mid-level lapse rates, and even some downdraft CAPE approaching or exceeding 1000 J/kg. This severe parameter space would be conducive for a few discrete storms that could produce large hail and damaging wind threats should storms develop. The SPC Day 1 Marginal Convective Outlook highlights this area well. There is a non-zero potential for a tornado in the late afternoon/early evening for the St. Croix River Valley east into inland NW WI, but given forecast 0-1km SRH values of generally less than 200 m2/s2 and LCL heights around 1200-1400 meters or greater, the tornado threat remains very low.

The second area of conditional strong to severe thunderstorm threats would be would be across far northern MN near the international border closest to where the surface low will track in conjunction with the shortwave mid and upper-level troughs and nearest the warm front and a secondary cold front during the mid-afternoon until around sunset. Seeing as this area will have less daytime heating due to later duration of morning convection, there remains some question as to how much instability will be available and whether or not storms can become surface-based. If they do become surface-based, there may be a 2-5 hour window of time where the environment would be conditionally supportive of strong to marginally severe hail and damaging wind gusts before the secondary cold front and steeper lapse rates aloft push east of the international border/Arrowhead region. Some CAMs also suggest that even if storms do develop, they may remain just north of the international border, as well.

Outside of thunderstorms, expect a very warm Spring day to shape up for Sunday, with many locations seeing highs in the upper 60s to mid 70s, though relatively cooler temperatures will likely be seen near Lake Superior, in the Arrowhead, and near the international border. Look for a lull in precipitation for the Northland Sunday night through Monday morning.

Monday Afternoon - Tuesday Morning:

Still some uncertainty regarding another period of conditional strong to severe thunderstorm potential Monday afternoon and evening. Another low pressure system and attendant warm front will likely push through south-central MN into northern WI late Monday through Monday night, bringing another round of showers and thunderstorms with it. There remains some question among global model ensembles and the few higher-res models as to how far north the warm front/warm sector and associated instability make it into the Northland. As of now, the favored area for the warm front to get north to would be from near or just south of the Brainerd Lakes east into NW WI, though onshore flow/lake breeze from Lake Superior may impinge on the northern extent of the warm sector in NW WI. A capping inversion may also play a factor in preventing better coverage/development of thunderstorms. However, should storms develop, the environment is once again favorable for a conditional strong to severe storm threat in the vicinity of the warm front and areas south into the warm sector. Steep lapse rates aloft would favor large hail as the main threat, though damaging wind could also be possible if storms can become organized north of the warm front or the warm front pushes far enough north into our southern counties to allow for surface-based thunderstorms. There hasn't been much consistency in models regarding storm morphology, but it should be noted that a limited subset of the model guidance does attempt to merge storms into a bowing line through central MN into the Twin Ports/I-35 corridor and NW WI late Monday afternoon and evening in association with a mid/upper-level shortwave. Should a linear segment develop, then the damaging wind potential would also increase. Showers and storms should come to an end Monday night into early Tuesday morning, bringing another lull in precipitation with it.

Tuesday Afternoon - Wednesday:

Yet another surface low pressure is poised to track northeast through southern MN into west-central or northern WI from late Tuesday into Wednesday as a stronger, compact upper-level trough moves through. There is lower confidence in the track of the low pressure with this system. Expect another round of showers and thunderstorms as this system passes through. For now, the main severe potential is largely south of the Northland. However, depending on the proximity of the warm front and warm sector to NW WI, we may see another strong to severe thunderstorm potential in portions of NW WI late Tuesday/Tuesday night. Precipitation should continue into Wednesday morning and eventually come to an end Wednesday afternoon or evening depending on how quickly the low pressure departs. Temperatures in the Tuesday-Wednesday timeframe have continued to trend upwards, so precipitation is favored to stay as all rain with this forecast update.

Beyond Wednesday:

No significant changes to the forecast in this timeframe due to high model variability. This timeframe of the previous discussion remains valid.

DISCUSSION

Issued at 253 PM CDT Fri Apr 10 2026

Current Weather: We warmly welcome spring back to the Northland with some temperatures in the 40s this afternoon. High pressure is bringing with it plenty of sunshine, though there are plenty of diurnal cumulus cloud out there. With mostly clear skies tonight, expect temperatures to fall below freezing, but this will likely be the last widespread below- freezing night for several days as we get much warmer air moving into the region.

Several Rounds of rain are expected starting Saturday afternoon and lasting through approximately Wednesday. Details are below.

Saturday Afternoon through Sunday Night: Broad southerly flow underneath the eastern side of a broad ridge will bring a noteworthy stream of moisture into the upper Midwest from the Gulf of America. Robust isentropic upglide is expected Saturday into Saturday night, and initially it should take a while for saturation to take place on Saturday with lingering dry air in place. It will likely be the usual increasing clouds and eventually rain making its way north starting Saturday afternoon. For Saturday afternoon and evening, this should be largely synoptically driven rain, though elevated lapse rates and instability are expected to increase overnight, so thunder will be possible. As far as rainfall amounts go, it is looking like there will be a bit of a moisture gradient with PWATs up to around 1.25" in NW WI and up to 1" in NE MN. Northwest Wisconsin should therefore see the brunt of the rainfall Saturday night with this first round. Ensembles are not necessarily in exact agreement with amounts, with a mean around 0.3 to 0.6" in NW WI into Sunday morning. Clustering is not great though, and with at least some convective processes expected, we can expect locally higher and lower amounts.

As we go into Sunday, it's still looking like we hold on to a conditional threat for isolated strong to severe thunderstorms. We will have very warm and moist air streaming up into the Northland ahead of a cold front that is expected to pass through sometime in the evening. We should see some elevated and possibly (depending how far north the warm front can make it) surface-based instability Sunday afternoon/evening. Thermal profiles in NW WI show deep near- surface moisture with somewhat steep lapse rates and dry air aloft. MUCAPE is looking to max out somewhere between 1000 and 1500 J/kg, so severe weather may not be widespread, but we could get a few storms capable of some large hail and/or damaging winds. Outside of storms, it is going to be warm! Many places in east-central MN into NW WI should see upper 60s to low 70s for highs.

As a cold front passes through Sunday evening, we may actually switch into a brief dry period later Sunday night through Monday morning.

Monday afternoon through Tuesday morning: Another low pressure system will make its way through with warm air advection in its wake. Broad surface-based instability is expected for a good chunk of Wisconsin Monday afternoon with another day of high temperatures in the 70s. There's still uncertainty on how far north the surface- based instability will make it, so this will be another conditional threat for any strong to severe storms in northwest Wisconsin. If there are any, large hail and damaging winds will be the main threats. Really the big trick with Monday might be dealing with a lake breeze as winds shift to northeasterly by the lake but remain southerly down towards Price County. Either way, we will probably see another round of rain, though it may be slightly less intense compared to Saturday night into Sunday.

Tuesday into Wednesday: Another surface low is likely to pass over Wisconsin with a potent upper-level trough aloft. This one was originally looking a bit colder such that some mixed precipitation could have been possible, but now it's looking like we should remain all rain. We may have enough embedded instability for a few thunderstorms, but severe weather is not expected. After a cold front passes through sometime around Wednesday morning, the rain should eventually end.

Late week into Next Weekend: We are looking to remain in a relatively wavy upper-level pattern to end the week. After a brief period of cooler temperatures mid-week, we could see another day of southerly flow and temperatures rising into the 70s. Models are generally suggesting a deep trough to the west that would create a Colorado-style low passing through somewhere in the Midwest followed by a blast of much cooler air to bring us into the weekend. It's possible we could see anything from thunderstorms to mixed precipitation depending on the track of the low and associated fronts. Models are too diverse in where any lows might track right now, except to say the Midwest in general. After seeing several days of above freezing temperatures (even at night), we may see lows fall below freezing again perhaps around Friday night.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 647 AM CDT Sat Apr 11 2026

VFR conditions prevail through early afternoon for BRD and until late afternoon/evening for other terminals. Winds are light and variable to start the period but will quickly increase out of the southeast mid to late morning, with gusts through this evening and into tonight at 17-25 kt for most terminals. Expect LLWS to develop this evening and tonight with a strengthening low-level jet.

Rain showers are forecast to start slightly earlier than previously forecast, particularly for BRD, and then spread northward this afternoon and evening, becoming more widespread this evening and tonight. HYR has the best potential to see isolated thunderstorms as rain expands northward this evening and tonight. Can't rule out a storm or two near DLH either, but confidence is low with this update. VIS and especially CIGS deteriorate quickly this evening and tonight as rain overspreads the area, with IFR to LIFR ceilings and MVFR to IFR visibilities in rain and low clouds.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 325 AM CDT Sat Apr 11 2026

No major marine concerns are expected in the next 48 hours. Winds become easterly today with gusts largely to 15 kt or less, though funneling in the SW arm of Lake Superior could bump winds up locally there to around 20 kt this afternoon and evening. Winds become southerly along the South Shore on Sunday with a few gusts that could approach around 20 kt. Expect rain and possibly some thunderstorms to move in starting late this afternoon into tonight with several additional rounds of showers and thunderstorms on Sunday into Wednesday.

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

FIRE WEATHER

Issued at 325 AM CDT Sat Apr 11 2026

Conditions start out drier this morning into midday as high pressure exits east and prior to moisture returning with low pressure coming in. As such, widespread showers with embedded storms don't look to get to the Brainerd Lakes and NW WI until this afternoon and gradually spread north during the mid-late afternoon into evening hours, becoming more widespread this evening into early Sunday. Given the delayed arrival of precipitation, minimum RH values of 30-40% are possible in NW WI and the I-35 corridor in the midday-early afternoon timeframe and across the Iron Range and north-central MN during the afternoon hours alongside southeast winds gusting to 15-20 mph. Precipitation will gradually end from SW to NE Sunday morning to midday Sunday, so there could be a period of time Sunday afternoon where min RH values drop to 30-45% alongside strong southerly winds gusting to 20-30 mph before a cold front moves through.

Several additional rounds of showers and thunderstorms are expected for late Sunday into Wednesday, though there will likely be short breaks late each night into midday between each round. The repeated rounds of precipitation will likely keep fire weather concerns minimal early to mid next week. We may have a dry, warm, and possibly breezy day on Thursday with some southerly winds before another round of precipitation arrives late this coming week.

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

HYDROLOGY

Issued at 503 AM CDT Sat Apr 11 2026

No changes to the Flood Watch for Bayfield, Ashland, and Iron counties in Wisconsin for this evening through early Wednesday morning. The watch remains medium confidence as it will be less the traditional sense for flash flooding potential and more into the potential for around 1-2" of rain over several days combined with the potential for 1-5 inches of snow water to melt out of the remaining snowpack. There has been a trend with the latest forecast for a slight decrease in rainfall amounts for the North Shore and northwest Wisconsin both for the Saturday afternoon - Sunday morning timeframe and for the total accumulations throughout the several rounds of showers and storms as a whole. Given the convective nature of the precipitation, some pockets of locally higher and lower rainfall totals will be possible. The precipitation from this afternoon through Sunday morning will set the stage for subsequent rounds of flooding potential. Should this first round continue trending down regarding precipitation amounts, then flooding concerns through early next week would also decrease.

We will still need to monitor for river rise/flood concerns along the North Shore as well given the deeper snowpack to 12-24"+ of snow depth and snow water equivalents of 5-7"+ there. However, the trend has been for the heaviest rain to remain south of the North Shore. Additionally, despite temperatures forecast to be above freezing for several days in a row, Lake Superior will keep the North Shore high temperatures about 10-20F colder and low temperatures 5-15F colder than areas farther inland. This should slow the snowmelt process there relative to the South Shore. Should precipitation forecasts and/or temperature forecasts increase for the North Shore for tonight through Wednesday, then flood headlines may be needed.

As for river and stream concerns, the highest potential for minor flooding remains with the Tyler Forks near Mellen, which could see minor flooding by late Monday or early Tuesday depending on how heavy the first couple rounds of rain are. The Bad River and Nemadji Rivers also have some potential to rise into action stage in the Monday to Tuesday timeframe depending on heavy rain locations and amounts.

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...Flood Watch from this evening through Wednesday morning for WIZ002>004. MARINE...None.