Forecasters predict above-average hurricane season in 2021: RMS

The National Oceanic and Atmospheric Administration (NOAA) and Colorado State University are among the climate forecasters warning of a record sixth above-average hurricane season in 2021.

That was the finding of RMS’ annual Northern Hemisphere Tropical Cyclone Outlook, which summarises the most prominent Atlantic and Western North Pacific basin forecasts for 2021.

The probability of a hurricane making landfall in the US increases during more active seasons, RMS noted. This year’s forecasts reflect the projection of phases of key atmospheric influences, including the El Niño-Southern Oscillation, Atlantic sea surface temperatures, and the Atlantic Multidecadal Oscillation. These trends are generally favorable for tropical cyclone development.

According to RMS analysis, incorrect Atlantic seasonal forecasts tend to be underestimates of activity, rather than overestimates, as was the case in 2020, when no agency correctly predicted there would be 30 named storms and 14 hurricanes. That made it the most active on record.

Meanwhile, Japan registered no tropical cyclone landfalls in 2020 for the first time in 12 years, which suppressed the level of insured tropical cyclone losses across Asia. This year, the majority of forecasts expect near-average number of tropical storms and typhoons to develop in the Western North Pacific.

The Western North Pacific typhoon season runs throughout the calendar year with no seasonal boundaries, although most of the activity typically occurs between May and November.