Colorado State University hurricane researchers are predicting a slightly below-average Atlantic hurricane season in 2023, citing the likely development of El Niño as a primary factor.
Eastern and central tropical and subtropical Atlantic sea surface temperatures are much warmer than normal, while Caribbean sea surface temperatures are near their long-term averages.
The tropical Pacific currently has neutral El Niño-Southern Oscillation (ENSO) conditions, that is, water temperatures are near normal in the eastern and central tropical Pacific.
Current large-scale conditions and forecasts indicate that a transition to El Niño is relatively likely in the next several months. However, there is considerable uncertainty as to how strong El Niño would be if it does develop.
El Niño tends to increase upper-level westerly winds across the Caribbean into the tropical Atlantic. The increased upper-level winds result in vertical wind shear which can tear apart hurricanes as they try to form.
When waters in the eastern and central tropical and subtropical Atlantic are warmer than normal, this tends to force a weaker subtropical high and associated weaker winds blowing across the tropical Atlantic.
These conditions lead to warmer waters in the tropical Atlantic for the peak of the Atlantic hurricane season. The anomalously warm eastern and central tropical and subtropical Atlantic favor an above-normal season.
Given the conflicting signals between a potentially robust El Niño and an anomalously warm tropical and subtropical Atlantic, the team stresses that there is more uncertainty than normal with this outlook.
Read more: https://engr.source.colostate.edu/csu-researchers-predicting-slightly-below-average-2023-atlantic-hurricane-season/#:~:text=Colorado%20State%20University%20hurricane%20researchers,Ni%C3%B1o%20as%20a%20primary%20factor.