A near-normal number of tropical storms and hurricanes could be ahead this summer and fall, the National Oceanic and Atmospheric Administration predicted Thursday. NOAA is forecasting a 40% chance of a near-normal season, a 30% chance of an above-normal season and a 30% chance of a below-normal season. In their first outlook of the season, NOAA forecasters stressed this is a somewhat uncertain outlook, and urged people to prepare for dangerous and rapidly intensifying storms.
NOAA is forecasting a range of 12 to 17 total named storms (winds of 39 mph or higher). Of those, 5 to 9 could become hurricanes (winds of 74 mph or higher), including 1 to 4 major hurricanes (category 3, 4 or 5; with winds of 111 mph or higher). NOAA has a 70% confidence in these ranges. Based on data from 1991 through 2020, the long-term average is 14 named storms, seven hurricanes and three major hurricanes.
Conflicting climatic signals are making this year’s tropical weather outlook especially difficult to pin down. According to NOAA, the biggest influence that might limit the number of storms is the global climate pattern known as El Niño, which has been developing over the past couple of months. El Niño has a domino effects on global weather patterns, and among them it tends to make conditions in the Atlantic less favorable for storms to organize and strengthen. On the other hand, unusually warm sea-surface temperatures throughout the tropical Atlantic could serve to encourage numerous tropical systems to form and strengthen. Scientists have recently observed record ocean warmth for this time of year in much of the Atlantic.
NOAA stated it’s pretty rare to have both of these factors going on at the same time. That’s why it’s prediction assigned relatively even probabilities of above, below, or near-normal number of storms this year.
The last below-normal hurricane season in the Atlantic came in 2015, during the last strong El Niño. Since then, there has been a string of active years for Atlantic tropical cyclones, including the record-setting 2020 season with 30 named storms.
The Atlantic Hurricane season will officially begin June 1 and end Nov. 30, although storms can and have developed outside that window. The first system to become a tropical storm this year will get the name Arlene.
NOAA plans to update the 2023 Atlantic seasonal outlook in early August, just prior to the historical peak of the season.