This Rare Storm Will Actually Be Dangerous...

Summary

A major severe weather outbreak is expected across the upper Midwest on Monday, April 28th, 2025, including a moderate risk for severe thunderstorms in areas like Minneapolis, Des Moines, and Cedar Rapids. Forecasters anticipate very large hail, damaging winds, and the possibility of a tornado outbreak, particularly in Iowa, Wisconsin, and Minnesota. Strong upper-level winds and intense atmospheric instability could fuel isolated supercells, increasing the tornado risk. The situation is complicated by model predictions, but the environment suggests the potential for extreme weather. Additional severe storms and heavy rainfall are expected in the following days.

Takeaways

• 😀 A dangerous severe weather and tornado outbreak is expected across the upper Midwest on Monday, April 28, 2025, including major population centers like Minneapolis, Des Moines, and Cedar Rapids.
• 😀 The Storm Prediction Center has issued a level 4 (moderate risk) for severe thunderstorms, with a 30% risk of large hail and damaging winds in certain areas.
• 😀 The risk for tornadoes is significant, with a 10%-15% probability of tornado outbreaks, particularly in Iowa, Minnesota, and Wisconsin.
• 😀 A potent upper-level trough and strong jet streak will combine to create ideal conditions for severe weather, pulling moisture from the Gulf of Mexico toward the Midwest.
• 😀 The environment will see high levels of convective available potential energy (CAPE), over 3,000 joules per kilogram, which is prime fuel for intense supercells.
• 😀 Early model predictions, including HR and Rufus, show mixed results, with HR models underestimating storm development and Rufus models showing strong supercells in other regions like Texas.
• 😀 The lack of convection shown by the HR model suggests that, once storms do develop, they could become very discreet and intense, leading to a higher likelihood of tornadoes.
• 😀 The GFS model predicts the most widespread convection, but it remains uncertain how the situation will evolve as the low-pressure system moves northeast into Canada.
• 😀 The outlook for Tuesday, April 29, 2025, suggests another severe weather event with potential for widespread thunderstorms from Texas to Canada, including cities like Buffalo, Pittsburgh, and Louisville.
• 😀 Significant rainfall is expected over the next several days, with the possibility of up to 5 inches in parts of northeast Oklahoma, southwest Missouri, and surrounding areas, raising flood concerns.

Q & A

What is the severe weather risk for Monday, April 28th, 2025, according to the Storm Prediction Center?

The Storm Prediction Center has issued a level 4 out of 5 moderate risk for severe thunderstorms across central Iowa, southeast Minnesota, and western Wisconsin, including major population centers like Minneapolis, St. Paul, Des Moines, Cedar Rapids, and Rochester.

What severe weather hazards are expected on Monday in the upper Midwest?

The expected hazards include very large hail, damaging straight-line winds, and the potential for a tornado outbreak, especially in Wisconsin, Minnesota, and Iowa.

What does the 'hatched' area in the storm outlook indicate?

The 'hatched' area in the storm outlook indicates regions where the storms are expected to produce significant severe weather, including potential tennis ball-sized hail or larger and the possibility of tornadoes.

What is causing the severe weather outbreak on Monday, April 28th?

A potent upper-level trough swinging out of the Rockies, combined with a strong jet streak, is interacting with a low-pressure system, leading to the formation of severe thunderstorms and a tornado outbreak.

What are the expected conditions in the warm sector on Monday, April 28th?

The warm sector is expected to see temperatures around 70°F with dew points in the 60s, which will help fuel the thunderstorms. There will also be a significant amount of convective available potential energy (CAPE), which is crucial for storm development.

Why might the HR model's forecast of no storms be concerning?

The HR model, known for underconvecting in dryline events, not showing storms could be a bad sign because it might mean that when storms do form, they will be very discreet and intense, capable of causing significant damage.

What does the Rofus model indicate for Monday, April 28th?

The Rofus model, which is known for overconvecting, shows a potential outbreak of supercells in Texas and Oklahoma but not as many in the upper Midwest. This could be a good sign for preventing widespread supercells but suggests a difficult forecast.

What is the significance of the significant tornado parameter (STP) on Monday?

The significant tornado parameter (STP) is off the charts in the upper Midwest, indicating an environment highly conducive to tornado formation. Even one supercell forming in this area could lead to a severe tornado outbreak.

How will the weather pattern evolve on Tuesday, April 29th, 2025?

On Tuesday, April 29th, the severe weather threat will continue, particularly in New York, Pennsylvania, Kentucky, Missouri, Arkansas, and Oklahoma. There will be another large storm system bringing severe weather, possibly extending into the Ohio Valley and the central US.

What is the expected rainfall over the next five days, and which areas are most at risk?

Over the next five days, areas in northeast Oklahoma, southwest Missouri, southeast Kansas, and northwest Arkansas could receive over 4-5 inches of rain, with potential flooding in flood-prone areas due to the continuous storms.