The Canadian Hurricane Centre is predicting an active storm season this year, with a projection of between 13 and 19 named storms of tropical storm strength.
Bob Robichaud, Warning Preparedness Meteorologist with the centre, said projections from the National Oceanic and Atmospheric Administration (NOAA) include six to 10 of those storms being hurricanes and three to six of those being Category 3 or stronger.
Robichaud presented the centre's annual seasonal outlook on Friday via a conference call. He said there are three factors involved in predicting how active the storm season will be.
The first is water temperature.
“Water temperature in the Atlantic right now is slightly above average and is predicted to remain warmer than average over the course of the hurricane season,” Robichaud said.
The second is wind shear. NOAA is not seeing much variation in wind shear happening this season.
“When we have a lot of wind shear, or really big changes in wind speed or direction with height, these columns of air that rise and actually end up forming the hurricane, actually get sheared apart before they can really get going,” Robichaud said. “So in an environment where we have low wind shear, we tend to have more hurricanes form in a given year.”
One of the things that influences wind shear is whether there is an El Nino pattern in the Pacific Ocean. The warm water currents in the Pacific typical of an El Nino lead to air pressure patterns that affect the global climate. The effects in the Atlantic includes more wind shear, which tends to keep the hurricane numbers lower if there's a neutral pattern in the Pacific, which is what officials are seeing now.
“And the third thing that is a big influencer of hurricane activity in the Atlantic is what we call the Atlantic multidecadal oscillation, which is basically a set of factors that influence pressure, water temperature in the Atlantic, which change on the order of 30 to 40 years. We've been in a (more active) period now since 1995, and there are no signs just yet that that is going to diminish.”
All those factors point to another “active hurricane season” this year,” he said.
“So we'd like to remind people that hurricane season starts June 1, and ends at the end of November.”
For the sixth year in a row, a storm developed in the Atlantic before that season officially started, he said. Tropical Storm Arthur stayed out to sea earlier this week.
Other names that are going to be used this year will include Cristobal, Gonzalo, Hanna, Kyle.
“All (are) storm names that some might remember here in eastern Canada as some of those named storms have caused problems here in Canada, as well,” Robichaud said.
“To get the latest information, for those who do not have our app, our Weather Can app can be downloaded on the app store or Google Play. To monitor the latest information on hurricanes, our website is hurricanes.ca and for tips on how to prepare, Public Safety canada has a very comprehensive list of things you can do at getprepared.ca”
He also stressed that Canadians should take preparedness seriously.
“I think the main message to Canadians at this point is to prepare for hurricane season as you do every year,” Robichaud said. “I think this year's going to be particularly important to have those preparations completed prior to the arrival of a storm because of all the other situations that we're facing. What we usually see when a storm is approaching, just one or two days prior to the storm, we see lineups at stores and so on and so forth. That is the thing you're really going to want to avoid this year, is being caught in some of those lineups with all of the new procedures now in various stores. So having those preparations done early and staying prepared over the course of the hurricane season is going to be particularly important this year.”