Overview
- Mid-July analyses of sea-surface temperatures and atmosphere patterns show a confirmed, strengthening El Niño in the tropical Pacific and a developing Atlantic Niña in the eastern equatorial Atlantic.
- NOAA’s seasonal outlook remains for below-normal Atlantic activity, forecasting 8–14 named storms, 3–6 hurricanes, and 1–3 major hurricanes, and forecasters say the twin anomalies reinforce that guidance.
- El Niño increases upper-level westerly winds and vertical wind shear over the tropical Atlantic that tear apart developing storms, and Atlantic Niña cools surface waters that reduce heat and moisture for thunderstorm formation.
- Observed signs of suppression already include unusually strong wind shear over the Caribbean and a slow start to the season with only Tropical Storm Arthur by mid-July, but officials stress that a single storm can still cause major damage.
- Scientists will keep monitoring models and observations because the timing and strength of both anomalies will shape peak-season and winter impacts, and a persistent cooling would mark only the sixth strong Atlantic Niña in roughly 40 years.