The Atlantic hurricane season begins June 1st, and it's going to be a busy one. On this week's edition of Weekend Insight TPR's Jerry Clayton speaks with the director of the National Hurricane Center, Michael Brennan.
Clayton: First of all, let's get to the official prediction.
Brennan: NOAA is expecting a very busy Atlantic hurricane season in 2024. We're forecasting an 85% chance of above normal activity in the basin. And we're expecting 17 to 25 named storms that would be tropical storm strength or greater, of which 8 to 13 would become hurricanes and 4 to 7, major hurricanes, a category 3 to 5.
So that's, that's a very active year. And in fact, it's the high end of those ranges or the highest numbers that NOAA has ever forecast in its May seasonal outlook.
Clayton: What are the main factors that are driving this year's prediction?
Brennan: We've had above average to record warm ocean temperatures across much of the Atlantic basin, including in the main development region and the deep tropical Atlantic that extends from the west coast of Africa, towards the Caribbean Sea. And those have actually been in place, going back even to last year. But what's different this year is we're expecting La Niña to develop in the eastern Pacific by the peak of hurricane season, which is an abnormal cooling of ocean water in the eastern Pacific, but results in more favorable conditions in the atmosphere, especially across the western part of the Atlantic basin in terms of reducing, vertical wind shear, which is the change of wind speed and direction with height, and also, overall, just more favorable atmospheric conditions for tropical storms and hurricanes to form.
We also see weaker easterly trade winds across the main development region of the Atlantic and a strong West African monsoon, which leads to more vigorous tropical waves that come off the coast of Africa and serve as the seeds for many, tropical storms and hurricanes, especially during the peak months of the season from August to October.
Clayton: Can you talk about how climate change may be a factor in this year's predictions?
Brennan: The strongest relationships we see between a warming climate and hurricanes are when we get into the water hazard space, and not as much into the exact numbers or intensities of the tropical storms and hurricanes themselves. So, what we're most confident in is that we have sea level rise ongoing, which is increasing the risk of the storm surge hazard because it's raising the base sea level. But then overall, the hurricane pushes that storm surge from the ocean onto dry land. So, it's starting from a higher level and it's expanding storm surge risk into new places.
The other thing that we're seeing is that a warming atmosphere holds more moisture. So, we're seeing increased rainfall rates and resultant freshwater flooding. So, that's concerning because that hazard in particular has killed more people than any other in Atlantic basin tropical storms and hurricanes in the United States over the last decade or so.
Clayton: Tell us about some of the newer technologies that are being deployed to monitor the Atlantic Ocean during hurricane season.
Brennan: NOAA is involved in several different observational tools, things like sail drones and gliders that are measuring conditions at the ocean surface and then down into the upper ocean.
We're also deploying, uncrewed or air systems or small drones that are being flown out of the NOAA hurricane hunter aircraft, but then can go fly down near the ocean surface for a couple of hours and measure the winds and the temperature and other conditions right there at the interface between the ocean and the atmosphere, which is an important place, because that's how hurricanes get their energy is by pulling it out of the upper ocean. And that allows us to get data in a place where we can't fly crewed aircraft, because it's not safe to be down that close to the ocean surface.
We're always advancing that technology, trying to get better observations for our forecasters here, but also get that data into the numerical forecast models from those platforms and also from the hurricane Hunter aircraft directly to help improve model forecasts of hurricane tracking intensity.
