Predictions for the 2019 Atlantic hurricane season were issued Thursday by both the National Hurricane Center in the United States and the Canadian Hurricane Centre.
The outlook calls for a near-normal season with 70 per cent confidence in the forecast. That forecast is calling for nine to 15 named storms, of which four to eight will reach hurricane strength, with two to four of those becoming major hurricanes (category 3 to 5).
Both organizations remind the public that the forecast is for the entire Atlantic basin and is not a prediction for how tropical systems will make landfall. They also stress it only takes one storm making landfall to make it a “bad season” and individuals and families should review their emergency preparedness plans and preparations.
The competing factors in the forecast this year are the presence of an El Nino phase in the Pacific Ocean. This means that surface waters in the southeastern Pacific are warmer, increasing winds over the Atlantic Ocean and that works to suppress tropical cyclone (tropical cyclone is a catch-all for tropical depressions, storms, and hurricanes) development there.
Favouring the development of storms this season will be above-normal sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, and a stronger west African monsoon. The warmer ocean waters provide more “fuel” for developing storms and the monsoon provides the ignition for storm development.
The National Hurricane Center is hopeful that new weather satellites, improved hurricane hunter aircraft instruments, and an upgraded computer forecast model will aid the forecast for individual storms through the season. Environment Canada and the Canadian Hurricane Centre will have access to these sources as well.
Bob Robichaud, meteorologist and host of the Canadian Hurricane Centre briefing, notes that there has been significant improvement in the forecast of the track of storms over the last few years; while predictions of intensity have not seen a comparable increase in accuracy.
Will the changing climate have any impact on the risk of tropical cyclones to Atlantic Canada? Robichaud answers that more research is needed into this subject, but current projections show that the number of tropical cyclones impacting Atlantic Canada may decrease in future years, while the strength of the systems that do arrive is likely to increase.
Still, on the subject of changing climate, Robichaud says, “one common thing that coastal communities have to deal with is sea-level rise. Some coastal communities are better able to handle a coastal flooding event and some are less able to do so. Those are the kind of things we are looking at, trying to determine what those vulnerabilities are.”
The season got off to an early start this year with the first named storm, Andrea, developing on May 20 before dissipating on May 21, with little impact.
The season officially runs from June 1 through Nov. 30. The greatest risk for Atlantic Canada tends to be later in the season, as both our surrounding ocean waters are warmer by then, and that it is the period of time when frequency of tropical cyclones peaks.
