April in Minnesota has a reputation for keeping residents on their toes, and the 2026 season opened with a reminder of just how violent the state's spring weather can be. On Monday, April 13, the National Weather Service confirmed three tornadoes touched down across southern Minnesota — marking the state's first significant severe weather event of the year. The storms produced hail the size of tennis balls, triggered tornado warnings across three counties, and sent a line of dangerous weather rolling eastward into western Wisconsin before warnings expired just before 10 p.m.
While no serious injuries were reported and structural damage was limited, the event underscored a recurring reality for residents of southern Minnesota: the spring severe weather season arrives fast, and when it does, it demands attention. Here's a comprehensive breakdown of what happened, why it matters, and what Minnesotans should know heading into the rest of the 2026 storm season.
How Monday's Storms Unfolded: A Timeline
The severe weather event on April 13 developed quickly, as spring tornado outbreaks often do. According to reporting on the storms, activity ignited just after 4:00 p.m. across southern Minnesota, with a line of severe storms taking shape from north of Worthington through Mankato, Faribault, and Northfield, tracking east-northeast as the evening progressed.
By 6:00 p.m., the storm line had intensified enough to become a serious threat. At 6:15 p.m., the National Weather Service issued a Tornado Warning covering Blue Earth County, Martin County, and Watonwan County — a broad swath of south-central Minnesota farmland where severe weather has historically caused significant agricultural and structural damage.
The first confirmed tornado touched down at 6:25 p.m. west of Amboy, Minnesota, in the southwest corner of Blue Earth County. It stayed on the ground for 21 minutes, finally lifting at 6:46 p.m. During that time, it damaged at least one farm outbuilding. Another tornado struck the town of Truman, Minnesota, where FOX Weather crews captured it on camera — providing some of the clearest visual documentation of the evening's most dramatic moments.
By 8:15 p.m., the severe threat had contracted to far southern Minnesota, with damaging winds and large hail remaining the primary hazards. At 9:30 p.m., the National Weather Service confirmed the final tally: three tornadoes from the day's storms. All tornado warnings expired by 9:45 p.m., ending Minnesota's first severe weather chapter of 2026.
The Hail: Tennis Ball-Sized and Widespread
While the tornadoes grabbed headlines, the hail produced during Monday's event was arguably the more widespread hazard. Reports of hail up to three inches in diameter — roughly the size of a tennis ball — came in from multiple locations across the affected area, with dozens of individual hail reports recorded throughout the evening.
Three-inch hail is not a common occurrence even during significant severe weather outbreaks. To put it in perspective, hail is classified as "severe" at one inch (quarter-sized). At three inches, it poses a genuine threat to vehicles, roofing, and anyone caught outdoors without shelter. A direct hit from hail that size can shatter car windshields, puncture aluminum siding, and strip the bark from trees.
For Minnesota farmers in the middle of spring planting preparation, large hail events like this one can be particularly costly. Fields that have been tilled and prepped are vulnerable, and equipment left outdoors is at risk. Even when tornado damage is limited, a widespread hail swath of this magnitude can generate insurance claims numbering in the thousands across a single county.
If you live in a tornado-prone region and haven't yet invested in a quality NOAA weather radio alert device for your home, spring is the time to act. These units provide direct broadcasts from National Weather Service offices and can wake you up during nighttime severe weather events when your phone might not.
Why Southern Minnesota Is a Severe Weather Hotspot
Minnesota doesn't always get the tornado-alley reputation of Oklahoma or Kansas, but southern Minnesota sits at the northern fringe of a climatological region where the ingredients for severe weather regularly come together. The flat terrain of the Minnesota River Valley and the surrounding agricultural plains offer little friction to stop rotating storms from organizing and intensifying.
The classic setup — warm, moist air pushing northward from the Gulf of Mexico colliding with cooler, drier air from Canada along a sharp frontal boundary — plays out repeatedly across this region each spring. April is typically one of the earliest months when these setups occur, and Monday's event fit that pattern almost exactly.
Blue Earth, Martin, and Watonwan Counties, which received tornado warnings on April 13, are no strangers to severe weather. This corridor of south-central Minnesota has seen multiple tornado outbreaks over the past two decades, including events that caused significant structural damage to small communities and farmsteads. The relatively sparse population density means that many tornadoes touch down in open fields without generating injury reports — but that same sparse density also means that warning systems and community preparedness are especially critical, since residents may be isolated when a storm hits.
What the National Weather Service Confirmation Process Looks Like
One detail worth understanding from Monday's event is the gap between when tornadoes are warned for and when they're officially confirmed. The National Weather Service issued Tornado Warnings based on radar signatures and storm spotter reports during the event itself. But the official confirmation of three tornadoes didn't come until 9:30 p.m. — roughly three hours after the first one touched down.
This is standard procedure. NWS meteorologists conduct damage surveys — either in person or via aerial reconnaissance — to verify that a tornado actually occurred, as opposed to a severe downburst or straight-line wind event that can mimic tornado damage. The surveys look for evidence of rotational damage patterns: debris fields that fan out in a circular or curved pattern, downed trees that fell in alternating directions, and the characteristic path width and ground-level evidence of a vortex.
In the case of the Amboy-area tornado, the farm outbuilding damage provided a clear ground truth for surveyors. The Truman tornado had the additional benefit of being filmed in real time by FOX Weather, making confirmation more straightforward. The third confirmed tornado's location and damage details were still being processed as of the initial reporting.
This confirmation process matters because it feeds directly into the historical record that meteorologists use to study tornado climatology, assess risk models, and communicate probabilities to emergency managers. Every confirmed event adds a data point to the understanding of where, when, and how often tornadoes occur — information that shapes everything from building codes to emergency response protocols.
Severe Weather Across the Region: A Broader April Picture
Minnesota's outbreak wasn't occurring in a vacuum. April 13 saw active weather patterns affecting multiple parts of the country simultaneously. In the Great Lakes, strong wind alerts were issued for southern Michigan through Monday morning, as the same broad atmospheric pattern pushing severe weather into Minnesota generated gusty conditions eastward across the Great Lakes region.
Pennsylvania was also dealing with weather hazards, with gusty wind alerts issued for parts of the state through Monday midday. Meanwhile, in the West, the weather story was the opposite extreme: south-central Oregon's Cascades were placed under a winter weather advisory running from Tuesday through Thursday, and the northern Blue Mountains of Oregon faced their own winter weather advisory for Tuesday and Wednesday.
The contrast is a vivid illustration of how April's atmospheric pattern can simultaneously produce spring tornado outbreaks in the upper Midwest and late-season mountain snowfall in the West. This is not unusual — it reflects the ongoing seasonal transition in the jet stream that typically peaks in volatility during April and May.
For communities near rivers and low-lying areas, spring severe weather also raises flooding concerns. The combination of saturated soils from snowmelt and heavy rain from storms creates compounding hazards. Readers in flood-prone areas should be aware that flash flood warnings have impacted other Midwest regions this spring as well.
What This Means: Analysis of Minnesota's 2026 Severe Weather Opening
Three tornadoes on the season opener is a notable start, but the more significant takeaway from April 13 is what it signals about the weeks ahead. Historically, Minnesota's severe weather season peaks in June, with May running a close second. The April 13 event is early — but it's not unprecedented, and it suggests that the atmospheric pattern supporting severe weather development is already in place across the region.
The relatively limited damage from this event — one farm outbuilding confirmed, no significant injuries — reflects a combination of luck and effective warning systems. The National Weather Service's radar coverage in southern Minnesota is well-established, storm spotters in the region are active and experienced, and tornado warnings were issued before the Amboy tornado touched down. That lead time matters enormously. Research consistently shows that even a few minutes of warning significantly reduces fatality risk.
But the 2026 season is just getting started. The same factors that produced Monday's outbreak — a volatile jet stream, early-season moisture return, and a region that offers few topographic barriers to storm development — will be present again. Residents of southern Minnesota, northern Iowa, and the Dakotas should treat April 13 as a readiness reminder, not a one-off. Review your emergency plan, confirm that your weather alert systems are functioning, and know in advance what shelter options you have if a tornado warning is issued while you're at home, at work, or in transit.
For those who want to go beyond a basic alert radio, consider a portable emergency weather kit that includes a hand-crank radio, flashlight, and basic supplies — particularly useful for rural residents where power outages following severe weather can last for extended periods. A storm shelter door anchor is also worth having for homes with interior safe rooms, since tornado-force pressure differentials can make doors difficult to hold shut without a mechanical assist.
From a broader climate perspective, the data on tornado frequency in the upper Midwest is a subject of active research. Some studies suggest that the traditional "tornado alley" centered on Oklahoma and Kansas may be shifting northward and eastward, with states like Minnesota, Wisconsin, and Illinois seeing increased tornado activity relative to historical baselines. April 13 adds one more data point to that evolving picture — and is a reason to take the broader question of long-term atmospheric shifts seriously.
Frequently Asked Questions
How many tornadoes were confirmed in Minnesota on April 13, 2026?
The National Weather Service confirmed three tornadoes touched down in southern Minnesota on April 13, 2026. The confirmation came at approximately 9:30 p.m., after damage surveys were completed. The storms represented Minnesota's first confirmed tornadoes of the 2026 season.
Were there any injuries or deaths from the Minnesota tornadoes?
No significant injuries or fatalities were reported from the April 13 tornado outbreak. Damage was largely limited to a farm outbuilding west of Amboy in Blue Earth County. The combination of timely tornado warnings and the storms primarily tracking through rural agricultural areas contributed to the low-damage outcome.
How large was the hail reported during the Minnesota storm outbreak?
Hail up to three inches in diameter — roughly the size of a tennis ball — was reported during Monday's storms. This is significantly above the one-inch threshold that defines "severe" hail. Dozens of individual hail reports were recorded across the affected area in southern Minnesota.
Which counties in Minnesota received tornado warnings on April 13?
The National Weather Service issued tornado warnings for Blue Earth County, Martin County, and Watonwan County in south-central Minnesota. The warnings were issued at approximately 6:15 p.m. and remained active as storms moved through the region before expiring by 9:45 p.m.
When is tornado season in Minnesota?
Minnesota's tornado season typically runs from April through September, with the peak months being May and June. However, as the April 13 event illustrates, significant tornado-producing storms can occur as early as mid-April when the right atmospheric conditions align. Minnesota averages approximately 45 tornadoes per year, though this varies significantly from year to year based on large-scale weather patterns.
Conclusion: A Season-Opening Reminder With Real Implications
Minnesota's first severe weather event of 2026 came and went in a single evening, leaving behind three confirmed tornadoes, widespread tennis ball-sized hail, and a farm outbuilding that bore the brunt of the season's opening statement. The outcome — no serious injuries, limited structural damage — is the best-case version of an event like this. But best-case outcomes require preparation, and the April 13 outbreak is a clear signal that the 2026 season is open for business.
The National Weather Service's confirmation process, the rapid storm spotter reporting, and the timely issuance of tornado warnings all functioned as intended. That's worth noting — because it's not always the case, and it's the product of sustained investment in meteorological infrastructure and community preparedness programs that deserve credit when they work.
For southern Minnesota residents, the message is simple: don't wait for the next event to check your preparedness. The season has begun, the pattern is active, and May — historically the most active tornado month in the state — is just weeks away. Know your shelter, know your alerts, and know that the National Weather Service confirmation of three tornadoes on April 13 is not an isolated curiosity. It's the opening chapter of a season that demands attention.
