National Hurricane Center forecasts a more active hurricane season for 2023

The NHC, responsible for issuing forecasts for tropical cyclones in the Atlantic, issued an update to its hurricane season forecast on Thursday. The new forecast calls for 14 to 21 named storms, an increase from 12 to 17 named storms in its original May forecast. The typical number of named storms during a season is 14, based on recent averages.

The official forecast also raised the forecast number of hurricanes from five to nine to six to 11. A typical season has seven hurricanes. In addition, two to five major hurricanes (Category 3 or higher) are now forecast, raised from one to four in the original May forecast.

There are several reasons for the increase in numbers. Water sea surface temperatures are at record highs across the Atlantic Ocean as a whole. This year has observed the warmest sea surface temperatures since records began being kept in 1950. Warm water temperatures, especially above 80 degrees, are the main fuel for tropical cyclones to form and rapidly intensify.

Also, El Nino's impacts have been delayed. Typically, El Nino causes more wind shear that interferes with tropical development. While El Nino is strengthening, there is less wind shear being observed and modeled over the next couple of months, which is not typical for El Nino conditions. Less wind shear helps tropical cyclones to intensify.

Additionally, active hurricane seasons, like forecast this year, bring an increased landfall threat to the East Coast. Matthew Rosecrans, NOAA's lead hurricane outlook forecaster, said that the chance of an East Coast landfall is doubled during active hurricane seasons.

2023 has seen five storms so far, including an unnamed subtropical storm in January. With only about a quarter of tropical activity through so far this season, about 75% of activity is still yet to come, including the climatological peak around Sept. 10. At this pace, 2023 would see 20 named storms, in line with the NHC's 14 to 21 named storms forecast.