Hurricane season could bring 12 to 17 named storms, forecasters say

There could be 12 to 17 named tropical cyclones this Atlantic hurricane season, similar to the number of named storms last year and a “near normal” number, forecasters said.

However, there is uncertainty in the outlook revealed Thursday by the National Oceanic and Atmospheric Administration, due to the unknown effect of competing weather patterns. Storms are named when their winds reach or exceed 39 miles per hour.

Rick Spinrad, the NOAA administrator, chimed in Thursday morning press conference that forecasters believed that from five to nine of the named storms could become hurricanes, meaning they would reach wind speeds of at least 74 mph. That could be one to four major hurricanes — Category 3 or higher — with winds of at least 111 mph

According to NOAA, there is a 40 percent chance of a near-normal season and a 30 percent chance of an above-normal season, but there is also a 30 percent chance of a below-normal season. An average Atlantic hurricane season has 14 named storms, seven hurricanes and three major hurricanes.

Fewer named storms are expected this year than in 2020 and 2021, active seasons that have exhausted names reserved for tropical systems. A less active season is expected primarily because of a developing El Niño, a periodic weather pattern that often reduces hurricane formation in the Atlantic through increasing wind shear, or changes in wind speed and direction from ocean or land surfaces to the atmosphere. Hurricanes need calm environments to form, and the instability caused by increased wind shear makes those conditions less likely.

El Niño could form in the coming months, most likely impacting during the central months of the Atlantic hurricane season, which takes place from early June to late November and peaks in September.

A wild card this year is the combination of favorable conditions created by warmer-than-average temperatures in the Atlantic Ocean’s surface, which could provide energy to fuel hurricanes, and the potential for an above-normal West African monsoon. The monsoon season produces storm activity that produces some of the more powerful and longer-lived Atlantic storms.

“It’s a pretty rare condition for both of these to be going on at the same time,” said Matthew Rosencrans, the lead hurricane season forecaster at NOAA’s Climate Prediction Center.

There is no significant historical context for a hurricane season with favorable Atlantic conditions and an El Niño developing at the same time. “I’ve only seen it once,” said Mr. Rosencrans, “and there are still hurricanes.”

Phil Klotzbach, a Colorado State University researcher who studies hurricanes, thinks the warmer-than-average ocean temperatures could mitigate the typical effects of El Niño, even though he expects “we’ll see slightly stronger vertical wind shear given just how strong El Nino likely will be.”

Weather researchers, including Mr. Klotzbach, are the pioneers of hurricane season forecasting and released their first forecasts in April. They then predicted that this year would be a slightly below average season, with 13 storms in the Atlantic Ocean. The teams updated forecast comes out on June 1.

“Remember, it only takes one storm to destroy a community,” said Mr. Spinrad, adding that regardless of the stats predicting a less active season, “if one of those named storms hits your home or your community, take it very seriously.”

While last year was predicted to be an above-average season, it turned out to be a near-average season – just like the forecast for this season – with 14 named storms. Three of those made landfall as hurricanes, including Ian, which tied for the fifth strongest hurricane on record to make landfall in the United States.

Even in average or below average years, there is a chance that a powerful storm will make landfall.

In a warming world, that chance increases. There is a solid consensus among scientists that hurricanes are becoming more powerful due to climate change. While there may be no more named storms in general, the likelihood that major hurricanes will form is increasing.

Climate change also affects the amount of rain storms can produce. In a warming world, air can hold more moisture, meaning a named storm can hold and produce more rain, much like Hurricane Harvey did in Texas in 2017, when some areas received more than 40 inches of rain in less than 48 hours. .

Researchers have also found that storms have slowed down in recent decades.

When a storm slows over water, it can absorb more moisture. When a storm slows overland, more rain can fall in one location, as was the case with Hurricane Dorian in 2019, which slowed to a crawl over the northwestern Bahamas, resulting in 22.84 inches of rain in Hope Town.

Research shows that there may also be other impacts on these storms from climate change, including storm surge, rapid intensification and a wider range of tropical systems.