What causes dangerous storms? Former astronaut Julie Payette explains

Last month, Hurricane Otis grew from a tropical storm to a Category-Five hurricane in less than 24 hours.

It left at least 100 people dead or missing and caused billions of dollars in property damage.

But what causes a storm to become so dangerous so quickly?

CTV News Montreal anchor Mutsumi Takahashi spoke with scientist and former astronaut Julie Payette to learn more about dangerous storms.

Watch the full interview in the video above, or read the transcript below, which has been edited for clarity and length.

TAKAHASHI: Most of us have never experienced a Category-Five hurricane. You have, twice. What is that like?

Payette: A storm is a storm. They all are developed the same way: it takes some basic ingredients and some disturbance winds. Even light wind can start a storm, and then moisture and temperature will do the rest and start churning water (and) air into really high into the atmosphere.

As it cools down, it produces more disturbance. We categorize a tropical storm versus a hurricane by the sustained winds that it produces. So, in the case of a category-five hurricane, it's a hurricane that has sustained winds of more than 250 km/h. It's really fast.

However, it's not necessarily just the winds that are dangerous in a hurricane. It really is the storm surge. It's this water that's being pushed by these winds into the land if the hurricane makes landfall.

TAKAHASHI: So then what happened with Hurricane Otis? Otis was not the first storm to take forecasters by surprise. There was Hurricane Harvey in 2017, Hurricane Michael in 2018, Hurricane Laura in 2020, so what's going on here?

Payette: And don't forget Sandy, which devastated New York, and produced massive power outages and flooded Manhattan. I was living in Maryland. We were surrounded by water.

Rapid intensification of hurricanes is a subject of intense research right now, because we've noticed more frequency of this explosive intensification of hurricanes. But, it is still very unpredictable because it depends on so many factors.

As a storm intensifies over warm water, if it meets another storm, or another front, or other meteorological events, it will reorganize. Sometimes, it will veer off to colder water and die off. Other times, it will veer into land and quickly provoke havoc.

Unlike earthquakes, we do have early warning (systems) because our models are getting more sophisticated. A storm can move, and as it eventually makes landfall, we can notify people and deploy emergency plans.

TAKAHASHI: What do these events mean for weather forecasters and getting emergency measures in place?

Payette: Yes. Ocean water is warming up, so we'll get more variability, frequency, and extremes in weather. So, having a plan is more important than ever. Preparedness is key. If they ask you to evacuate, please do.