The harbingers of the 2015 hurricane season are slowly taking shape in a body of warm water just east of the boundary of the Central North Pacific Basin. The location — far west and near to Hawaii for this time of year — has tropical weather forecasters from Hawaii to Miami scrutinizing the disturbances.
The closest mass of unstable weather, located about 1,600 miles east of Hilo, has a 70 percent chance of forming into a tropical cyclone in the next day or two as it moves slowly northwest. Beyond that time, it is not expected to intensify much as the energy of the system is sucked away by another developing system just to the northeast.
That second disturbance has a 60 percent chance of becoming a tropical cyclone over the next few days as it tracks northwest at 10 to 15 mph.
“We typically don’t see a lot of activity this time of year in that area,” said Derek Wroe, a forecaster with the National Weather Service in Honolulu. “We have not had a tropical cyclone form in the Central Pacific in May since 1971. It would be a very rare thing if it happened, but sometimes Mother Nature plays by her own rules.”
And while meteorologists are eyeing these first manifestations of what could be a hurricane-friendly, El Nino-fueled season, they’re not yet sounding an alarm. That’s because there’s a large band of water stretching between the Hawaiian Islands and the developing systems that’s still too cold to sustain hurricane formation. The fledgling storms are expected to hit this stretch of unfavorable water and disintegrate in the coming days.
“Closer to Hawaii and more typical for this time of year, ocean temperatures have not yet warmed enough to sustain hurricane development,” said Matthew Widlansky, a postdoctoral fellow at the International Pacific Research Center in Honolulu. “Surface temperatures warmer than 80 degrees are typically required and we are at about 77 degrees so far in May.”
With that said, it does look like the eastern Pacific will be off to a busy start, said Widlansky, who studies Pacific climate variability.
“The two tropical disturbances are forming in an area where sea surface temperatures are much warmer than the long-term average for this time of year — about 2 to 3 degrees above normal, and this extra heat supports further storm development,” he told West Hawaii Today.
“The same region has seen enhanced storminess and cloud cover for much of May, associated with a strengthening El Nino.”
The clues are in that El Nino forces are indeed announcing their presence with the formation of these systems, which at this time of year are generally located much closer to the coast of Central America, Wroe said.
“Whether it passes into our area is another question,” he said of the disturbance that is farthest west. “It is moving very slowly.”
Email Bret Yager at byager
@westhawaiitoday.com.
