Wednesday marks the first official day of hurricane season for the Central Pacific basin following an active and record year last year.
For our 2015 hurricane season, forecasters recorded 15 named tropical cyclones to cross into the Central Pacific basin, which is an all-time record especially when considering the number of major hurricanes. Within the Central Pacific, there were seven tropical storms, three Category 1 hurricanes, one Category 3 hurricane, four major hurricanes (each peaking at Category 4 strength), and even a tropical depression in late-December.
Even though we are making a transition to La Nina -- known as the opposite of El Nino -- the Central Pacific Hurricane Center is still forecasting a near-average or slightly above-average year with four to seven tropical cyclones. We also have in the record books Hurricane Pali that churned over the Central Pacific in early January, already placing one in the 2016 weather books. This was the earliest hurricane on record for the Central Pacific basin.
We are also seeing a band of sea surface temperatures that are very warm, stretching from the coast of Mexico to even Hawaii and beyond with sea surface temperatures at 80 degrees and above. This can easily provide fuel for tropical cyclones during the summer months into early fall.
Usually during La Nina, conditions typically suppress hurricane activity since there is increasing wind shear – an abrupt change in vertical wind direction that normally leads to disrupting hurricane development and potential organization -- and the atmosphere also tends to have a large area of sinking air that keeps tropical cyclones at a minimum during La Nina conditions. However, since this season is following a very active season, it will take time to transition, and as of now, the prediction of La Nina is based off of long-term climate models. There aren't significant signatures or signs of it yet, but it is expected to come.
Globally, ocean temperatures remain fairly warm in both the Atlantic and Pacific. The Atlantic basin is also expecting a near average year. Last year, was a very slow year for them due to strong El Nino conditions.
Also, on this first day of hurricane season, the Hawaii News Now weather team is focusing on the Eastern Pacific, where a cluster of clouds is becoming more organized. The area is located about 1,000 miles south of Baja. It is over very warm sea surface temperatures and its circulation is looking a little more pronounced on the tropical satellite imagery. In fact, there is now a 60 percent chance these thunderstorms will become a tropical storm within 48 hours and a 90 percent chance within five days. This is our breeding grounds for hurricanes and many storms that originate from the Eastern Pacific basin have crossed into the Central Pacific basin.
With the first official day of hurricane season here, and with us expecting a near average year with four to seven tropical cyclones forecast to develop within the Central Pacific basin, it is wise to be prepared. As we know, it only takes one.
We will have the latest information on our Hawaii News Now weather website under the Hurricane Center tab.