Oleochem Analytics — The National Oceanic and Atmospheric Administration (NOAA) released its 2021 Atlantic hurricane season outlook May 20, predicting another active season.
NOAA expects a 60% chance of an above-normal number of named storms, a 30% chance of a near-normal season, and a 10% chance of a below-normal season. However, experts do not anticipate the historic level of storm activity seen in 2020.
The NOAA outlook predicts a likely range of 13 to 20 named storms with sustained winds of at least 39 mph. It also says 6 to 10 of those could become hurricanes, with winds of at least 74 mph, including 3 to 5 major hurricanes of category 3 or higher, with winds of at least 111 mph. NOAA provides these ranges with a 70% confidence.
Last month, NOAA updated the statistics used to determine when hurricane seasons are above-, near-, or below-average relative to the latest climate record. Based on this update, an average hurricane season produces 14 named storms, of which 7 become hurricanes, including 3 major hurricanes in a typical season.
NOAA raised its assessment of the “normal” number of storms due to the significant uptick in activity in recent decades, up from the previous level of 12 named storms, 6 hurricanes and 3 major hurricanes.
“ENSO-neutral and La Niña support the conditions associated with the ongoing high-activity era,” said Matthew Rosencrans, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center. “Predicted warmer-than-average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, weaker tropical Atlantic trade winds, and an enhanced west African monsoon will likely be factors in this year’s overall activity.”
According to the NOAA outlook, El Niño Southern Oscillation (ENSO) conditions are currently in the neutral phase, with the possibility of the return of La Niña later in the hurricane season.
The Atlantic hurricane season extends from June 1 through November 30.
