The 2021 Atlantic hurricane season is shaping up to be busier than average. There’s a 60 percent chance of an above-normal season this year. Up to 20 named storms and as many as 10 hurricanes are expected, according to a forecast published today by the National Oceanic and Atmospheric Administration (NOAA). They also forecast up to 5 major hurricanes, which have winds reaching 111 mph or higher.
Hurricane season officially starts on June 1st. But for the first time this year, NOAA began issuing routine Tropical Weather Outlooks two weeks early. More storms have developed ahead of the official season in recent years, to the point where NOAA and the World Meteorological Organization are considering moving the official start date of the season up to May 15th.
This all reflects “new normals” brought on by climate change. Every ten years, using data from weather stations, NOAA updates the 30-year climate record it uses to determine what’s considered “normal.” Using that data, NOAA recently raised the bar for what’s considered a typical number of storms in a single season. The average is now 14 named storms and seven hurricanes in a season. Prior to that update, an average season had 12 named storms and six hurricanes. The new numbers reflect how much the world has already changed over the past decade, as well as technological advances that help meteorologists better detect storms.
“Now is the time to ensure that you have an evacuation plan in place, disaster supplies on hand, and a plan to secure your home quickly,” acting NOAA Administrator Benjamin Friedman said in a press briefing today. “It was a mere six months ago that the most active Atlantic season on record ended, and here we are now on the cusp of a new hurricane season.”
In true 2020 fashion, last year’s Atlantic hurricane season was terrible. Coastal communities reeled under repeated blows — Louisiana faced five named storms while Central America was hard-hit by Hurricanes Eta and Iota in quick succession. A whopping 30 storms grew strong enough to earn a name, and thirteen of those intensified into hurricanes. That was even more than the “extremely active” season NOAA forecasted. They’d expected more storms because a climate pattern called La Niña developed, which can lead to more hurricanes in the Atlantic. NOAA said that La Niña could develop again later in the season, although the agency doesn’t expect this year to be as bad as last season.
The jury is still out on whether climate change makes storms more frequent — but there is evidence that they’re growing stronger. Hurricanes are also intensifying more rapidly and keeping more of their strength upon making landfall. Those trends raise the risk that these storms pose to people, since they give communities less time to prepare and can reach farther inland. Tropical storms draw their strength from the sea’s heat energy. Hotter global temperatures translate to warmer seas and, consequently, more heat energy for storms to tap.
Forecasts made last month by Colorado State University (CSU) and IBM’s The Weather Company also predicted a busy season. CSU expects 17 named storms while the The Weather Company forecast 19. They both expect eight hurricanes and four major hurricanes to develop.