Atlantic hurricane season takes new twist; CSU tweaks threat outlook

The Atlantic hurricane season should deliver another 15 named storms in 2022 and a total of eight hurricanes, of which four could hit category 3 or higher, a key research institute has claimed in a light downgrade to the 2022 threat level.

"We have decreased our forecast but continue to call for an above-average 2022 Atlantic hurricane season," forecasters at the Colorado State University’s Tropical Weather & Climate Research department said in the August update to their 2022 forecasts.

The moderate downgrade versus the June update put forecast levels back down to or below the initial predictions from April.

The basic ingredients for an above-normal storm season remain in place, chiefly warmer water temperatures in the tropical Atlantic, analysts wrote, but subtropical Atlantic waters have "anomalously cooled," holding out hope that wind shear conditions may subvert more early storm systems.

Counting three named storms to date, CSU now expects 18 named storms for the full season (June: 20, April: 19) spread across 85 days (95, 90). The group expects eight hurricanes (10, 9) including four major hurricanes of category three or higher (5, 4).

Adjusted for one standard-deviation uncertainty, CSU puts the named storm count in a range of 15 to 21, the hurricane count in a range of six to ten and the major hurricane count in a range of three to five.

The chance of major hurricane landfall anywhere on the US continental coastline was slashed to 68% (June: 76%; April 71%), all above the 52% rate noted over the past century.

The CSU model is based on five statistical forecasting schemes, averaged and then adjusted for factors not explicitly covered in any of the base models. The final reading in August fell above the combined model output in deference to the higher readings achieved earlier in the year.

CSU will begin publishing two-week forecast updates every other Thursday through October.

Revised forecasts follow hot on the heels of an updated view from the US government's National Oceanic and Atmospheric Administration (NOAA).

NOAA now sees a 60% chance of an above-normal season, down from 65% when prior forecasts were issued late May. By storm count, NOAA only trimmed the top of the 2022 forecast ranges. NOAA is predicting a named storm count of 14-20 (prior: 14-21), of which 6-10 could evolve into hurricanes (flat vs May), of which three to five could hit category 3 or higher (prior: 3-6). Three named storms have already run their course, leaving 11-17 to go.