NEW ORLEANS — The experts at NOAA’s Climate Prediction Center say the 2021 hurricane season is going to be above normal.
NOAA predicts a 60% chance of an above-normal year. This would mean 13-20 named storms, 6-10 of those becoming hurricanes, 3-5 of which could be major hurricanes (Category 3-5).
The average number of named storms per year is 14, which is higher this year because NOAA is using an updated 30-year set of statistics from 1991-2020.
NOAA says there is still a 30% chance of a near-normal season. And a 10% chance of a below-normal season.
One reason NOAA is leaning towards an above-normal season is that the Atlantic Basin is in an era of high activity that began in 1995. This includes warmer sea surface temperatures, which help storms get started and get stronger.
There are also weaker trade winds and weaker vertical wind shear, which would both make it harder for storms to form if they were present. And, a wetter west African monsoon may contribute to more storms.
The El Nino and La Nina balance is also more favorable for storm formation.
El Nino is the warming of waters in the tropical Pacific Ocean. When there is an El Nino, it lessens storm activity in the Atlantic Basin.
La Nina is the cooling of those waters. And it corresponds with an increase in storm activity.
At the beginning of the 2021 hurricane season, there is neither an El Nino nor a La Nina. It’s neutral. But, there is a possibility that a La Nina may form.
This scenario reinforces the prediction of an above-normal year. If that prediction comes true, this will be the sixth consecutive year with above-normal activity.
