LITTLE ROCK, Ark. – Forecasters with the National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center are predicting an above-normal Atlantic Hurricane Season for the 2020 season.
The outlook which was released on May 21, 2020, predicts a 60% chance of an above-normal season. There’s a 30% chance that the season will be near-normal and just a 10% chance of it being below-normal.
In a “normal” season, there are 12 named storms, 6 of which become hurricanes, 3 that are considered major hurricanes (Category 3, 4 or 5).
To break it down in numbers, there’s a prediction of 13-19 named storms. Of those named, 6-10 may become hurricane status. Further, 3-6 of them could become major hurricanes.
The Atlantic Hurricane Season begins on June 1 and ends on November 30. Tropical systems can form outside these dates, but from late spring through mid-fall, tropical development is most likely as ocean waters tend to be warmest.
There is a strong chance for above normal activity in the Atlantic due to multiple atmospheric and oceanic factors.
Forecasters note the El Niño Southern Oscillation is likely to be neutral or trend towards a La Niña pattern.
During El Niño, warmer than normal water pools in the eastern Pacific Ocean. Meanwhile, in the Atlantic Basin, there is typically greater differences in vertical wind speed or direction (wind shear) and trade winds, leading to more stability in the atmosphere. Therefore, an El Niño pattern would suppress hurricane activity with a stable environment and strong wind shear that is destructive to hurricane formation.
During La Niña, there are typically below average water temperatures in the eastern Pacific Ocean. Meanwhile, in the Atlantic Basic, there is weaker vertical wind shear and trade winds, along with less stability of the atmosphere. This pattern allows for better hurricane formation as storms are more likely to spark due to the instability and atmospheric flow within a storm maintains itself with lack of wind disturbances.
Warmer than average sea surface temperatures, along with reduced vertical wind shear and trade winds, plus enhancement of the west African monsoon (where tropical waves typically form and flow westward) will all enhance the instability of the atmosphere over the Atlantic Basin and Caribbean Sea allowing tropical system formation to be elevated for the 2020 season.
Again, this is just a forecast prediction. NOAA often releases an updated forecast through the middle of the season based on changing factors and activity in the atmosphere’s patterns.