BRIDGETOWN, Barbados, Wednesday February 17, 2016 – Just over a month ago, an unusual Atlantic disturbance turned into Hurricane Alex, making it the first hurricane of 2016 and only the second January hurricane on record since 1938.
Alex weakened and was downgraded to a tropical storm before it made landfall in the Azores, but was still an unexpected start to the year, leading many people to wonder what kind of hurricane season lies ahead.
While it’s too early for scientists and meteorologists to say with any certainty, they have been releasing long-range predictions since December, and the outlook appears to suggest a return to average conditions.
But with a strong El Niño currently in the Pacific, which some climate researchers and meteorologists believe to have peaked, the question now is how will it influence the Atlantic tropics in 2016 and how quickly will conditions shift to its opposite, La Niña?
The respected Colorado State University Department of Atmospheric Science tropical storm and hurricane forecast team of Klotzbach and Gray will issue their first official forecast in April, and have only provided a qualitative outlook for the 2016 hurricane season so far.
Klotzbach and Gray assess potential 2016 Atlantic hurricane activity based on the strength of the Atlantic Multi-Decadal Oscillation (AMO) and thermohaline circulation (THC) and the phase of the El Nino Southern Oscillation (ENSO).
Their long-range assessment gives the greatest chance, at 35 percent, that in 2016 the AMO/THC is above-average and some El Niño impacts remain, resulting in a seasonal average Accumulated Cyclone Energy (ACE) of 120.
That would indicate a 2016 hurricane season with around 12-15 named storms, 6-8 hurricanes and 2-3 major hurricanes, which is an average year typically.
The Colorado State team nevertheless gave the 2nd highest chance, at 25 percent, that AMO/THC becomes above-average in 2016 and El Niño conditions dissipate, resulting in ACE of 170 for the 2016 hurricane season.
That would be above-average, indicating a chance of 14-17 named storms, 9-11 hurricanes and 4-5 major hurricanes.
Meanwhile, London-based Tropical Storm Risk (TSR), have predicted that the 2016 hurricane season will see activity 20 percent below the long-term average. They, too, stressed the uncertainty of a long-range forecast.
TSR uses as its main predictor the forecast July-September trade wind speeds over the Caribbean Sea and tropical North Atlantic, which influence cyclonic vorticity (the spinning up of storms) as well as vertical wind shear, which can tear storms apart, in the main hurricane track region of the Atlantic.
TSR’s long-range forecast predicted ACE of just 79 for the 2016 season, which would indicate 13 named tropical storms, 5 hurricanes and 2 major hurricanes.
That works out to above-average for the formation of named storms, but slightly under for hurricanes and major hurricanes.
Overall, TSR said there was a 25 percent probability that the 2016 Atlantic hurricane season ACE would be above-average, a 34 percent likelihood it would be near-normal and a 41 percent chance it would be below-normal.
So the long-range forecasts suggest a near-average year, but a chance of more named tropical storms than the long-term trend and perhaps a higher than normal chance of landfall in the US as El Niño’s influence on tropical storm steering wanes.
The April 2016 forecasts promise more certainty on the outlook, but even then conditions can change and steering jet stream winds can impact the direction of storms much nearer the season.
The 2016 Atlantic hurricane season runs from June 1 through November 30.