Colorado State University (CSU)’s tropical weather researchers have downgraded their 2026 Atlantic hurricane season outlook.
In a new forecast, issued on 10 June, they cited growing confidence that a moderate-to-strong El Niño will suppress storm activity during the peak summer months.
The update predicts 11 named storms, five hurricanes and two major hurricanes. The numbers are down from April’s predictions of 13, six and two, respectively.
The probability of at least one major hurricane tracking through the Caribbean has dropped from 35% in the April forecast to 26% – lower than the long-term average of 47%.
The revision is driven primarily by the outlook regarding El Niño, which inhibits hurricane activity by increasing vertical wind shear in the Atlantic.
“Our best estimate is that we will have a moderate to strong El Niño this summer and fall,” the latest forecast said.
“We believe that the odds of a strong El Niño have increased over the past few weeks.”
In April, the CSU team was working from a base of weakening La Niña conditions, with El Niño considered likely but uncertain in strength. That uncertainty has now largely been resolved.
The US National Oceanic and Atmospheric Administration now places the probability of El Niño at 98% for the August-to-October peak season, with a 40% chance of a strong event.
CSU’s models show that a strong El Niño would produce the highest wind shear across the Atlantic’s main hurricane development region since at least 1981, creating conditions that suppress storm formation and intensification.
Atlantic sea surface temperatures have also shifted in a less favourable direction for hurricane activity.
Where April’s report noted warmer-than-normal waters in the western tropical Atlantic, the latest data show temperatures now near average.
“Over the past several weeks, trade winds across the Caribbean have been stronger than normal, consequently eroding most of the warm anomalies that formerly prevailed in this region,” the forecast said.
CSU researchers cautioned that uncertainty remains over El Niño’s final magnitude and the trajectory of Atlantic sea surface temperatures through the season.
Their next update is scheduled for 8 July.
