The National Oceanic and Atmospheric Administration (NOAA) indicated on Thursday that the 2023 Atlantic hurricane season is likely to be exceptionally active, driven by a combination of sluggish El Niño onset and historically high ocean temperatures.
In its annual hurricane update, traditionally released in August following an initial outlook in May, NOAA has revised the probability of an “above-normal” hurricane season to 60 percent, a substantial increase from the 30 percent forecasted in May.
According to the agency’s projections, the Atlantic region could experience between 14 to 21 named storms, with six to 11 of those intensifying into hurricanes. Among these hurricanes, two to five are predicted to escalate into major hurricanes—classified as Category 3 to 5, boasting winds of 111 miles per hour or more. The projection also includes a 25 percent chance of a season aligning with historical norms, which is down from the initial estimate of 40 percent. The likelihood of a below-normal hurricane season stands at 15 percent. NOAA offers this forecast with a confidence level of 70 percent.
The current year has witnessed a dynamic start, hosting five tropical storms, one of which developed into a hurricane.
Matthew Rosencrans, NOAA’s lead seasonal hurricane forecaster, articulated that the upcoming months, spanning August to October, mark the peak of hurricane activity, encompassing around 90 percent of all hurricane occurrences. The official hurricane season extends until the conclusion of November and typically yields 14 named storms, seven of which mature into hurricanes, and three escalate into major hurricanes.
Despite El Niño typically suppressing the severity of hurricane seasons, this year’s El Niño demonstrated a gradual onset, essentially nullifying its usual impact. Rosencrans highlighted that under ordinary El Niño conditions, the occurrence of two named storms could be expected, whereas the current year has already witnessed five.
Compounding the mitigated influence of El Niño is the unparalleled warmth observed in the Atlantic waters, significantly heightening the prospects of a tumultuous hurricane season. Rosencrans underscored that sea surface temperatures during June and July have reached their highest point since the commencement of records in 1950, surpassing the norm by 1.23 degrees Celsius.
He noted, “Comparing temperatures from 1950 until now, every single year has exhibited cooler Atlantic temperatures than those we are observing now. Elevated water temperatures create a favorable environment for heightened storm formation.”
Rosencrans emphasized that the augmented warmth likely played a pivotal role in nurturing two tropical storms within the deep tropics during June. Such occurrences during June and July often serve as early indicators of an impending active hurricane season.