El Nino conditions developing this summer could lead to a busier than average hurricane season, experts said Wednesday morning.
Central Pacific Hurricane Center officials predict four to seven tropical cyclones in the Pacific Basin this year. The hurricane season begins June 1. Overall, they give this season an 80 percent chance for a normal to above average number of tropical storms to form.
El Nino conditions typically mean a more active hurricane season in the Central Pacific, officials said. Historically, that has meant six to seven cyclones per year since 1970 when those conditions are present.
Since 1971, tropical cyclone activity tends to peak in July, August and September, National Weather Service Warning Coordination Meteorologist Mike Cantin said. August has recorded the most, with 74, followed by July with 45 and September with 37.
The center has only recorded three cyclones or hurricanes in November, but one of those was Iwa in 1982.
“Later in the season, there are more fronts, more lows,” Cantin said, adding that leads to an increased probability of landfall.
Cantin noted that a majority of storms generated during El Nino conditions — warmer than normal sea surface temperatures in the equatorial Pacific Ocean — happen during the summer months. Still, Cantin added, the likely El Nino system is “no guarantee” that the state will experience more storms than usual.
The two seasons with the most storms since 1971 were 1992 and 1994, both of which had 11 storms. Both years were also El Nino years. But the next highest season since then, 1997, was a year without either El Nino or La Nina, which is characterized by cooler than average sea surface temperatures. The most recent El Nino year was 2009, when seven systems formed.
Last year was an average one, with six storm systems generated. Three came close to Hawaii, but another was very close to the international date line and didn’t impact the state at all, Cantin said.
Scientists haven’t yet shown a correlation between climate change and changes in tropical storms in the Pacific, Cantin said.
Storms here tend to follow a “multidecadal cycle of up to 20 years of quieter seasons, then above average,” he said. “On the decade scale, we’ve been in the quieter end over the past 10, 15, 20 years. It looks like we should be transitioning (to a busier season), but we may not.”
Cantin offered a bit of advice for Hawaii residents as hurricane season approaches.
“The main point is, no matter what the outlook is for, all it takes is one system,” he said. “Each and every year, we have to be prepared for that one system.”