NOAA’s forecast calls for:
- Eleven to 17 named storms – including April’s Tropical Storm Arlene.
- Five to 9 of which would become hurricanes.
- Two to 4 of which would become major hurricanes.
The 30-year historical average (1981-2010) for the Atlantic Basin is 12 named storms, six hurricanes and three major hurricanes. A major hurricane is one that is Category 3 or stronger on the Saffir-Simpson Hurricane Wind Scale.
According to NOAA, “The outlook reflects our expectation of a weak or non-existent El Niño, near- or above-average sea-surface temperatures across the tropical Atlantic Ocean and Caribbean Sea and average or weaker-than-average vertical wind shear in that same region.”
Strong El Niños typically lead to increased wind shear in parts of the Atlantic Basin, suppressing the development or intensification of tropical cyclones in the Atlantic, so the prediction for weak conditions increased the chance for more activity this season.
“The climate models are showing considerable uncertainty, which is reflected in the comparable probabilities for an above-normal and near-normal season,” NOAA added.
The Weather Company updated its seasonal forecast earlier in May and expects a total of 14 named storms – seven hurricanes and three major hurricanes – this season. This is an increase from its forecast compared to April due to a couple of factors.