Understanding the 2014 Central Pacific Hurricane Season forecast

Justin Cruz with Ray Tanabe and Mike Cantin

The Central Pacific could see increased storm activity this hurricane season, according to an outlook by the National Oceanic and Atmospheric Administration’s Central Pacific Hurricane Center.

Forecasters predict four to seven tropical cyclones during the 2014 Central Pacific Hurricane Season with an 80-percent chance of normal or above normal cyclone activity.

Justin Cruz sits down with Mike Cantin, warning coordination meteorologist, and Ray Tanabe, meteorologist in charge, at the National Weather Service to discuss the forecast.

JC: Let’s go over those numbers. How many tropical cyclones can we expect this hurricane season?

hurricane graphic cyclone forecast

MC: Our outlook for this year is a little bit above average – four to seven total tropical cyclones somewhere in the Central Pacific during this season.

JC: The season begins June 1 and lasts all the way until the end of November. Why even a forecast? Why not just wait until one comes and then everyone will be informed about it? How does a forecast help?

MC: I think the forecast is a good way to remind everyone that hurricane season is coming. For a lot of the planners out there, maybe it’s the City and County folks, maybe it’s statewide folks, maybe it’s the military folks that are out there with assets and people that are moving in and around the Hawaiian islands. The outlook is an idea of what to expect for the season so they can plan and make better decisions. But for the general public at large, it’s really about understanding that hurricane season is coming and the threat’s out there.

JC: The number of hurricanes (predicted) is higher than an average season. How many do we get as an average season?

RT: An average season sees four to five tropical cyclones in the Central Pacific. This year we’re looking at a near to above-normal season for various factors including the development of El Nino coming this summer.

JC: Let’s talk about El Nino. Can you explain what El Nino is and what it does to the ocean water?

RT: What El Nino means is that we have a pool of warmer-than-average sea surface temperatures in the Central Pacific along the equator. That warm pool will extend all the way into Central America. Warmer water means a more active tropical cyclone season. It also means some stronger tropical cyclones as well.

JC: Is it forecast to become El Nino or is it in place now?

RT: El Nino is not in place now. We’re currently in El Nino neutral conditions and what that means is sea surface temperatures are right about where they should be for this time of year. But we are predicting about a 65 percent chance that El Nino conditions will develop by July.

JC: How many degrees are we talking about here? A half-degree? Three degrees?

MC: Right now it’s about a half-degree Celsius above normal so right around a degree or so above normal. The forecast is to be right about that, so that’s kind of the intensity of the El Nino. When you get to half-degree Celsius or more above normal for the right amount of time, about a third of the year, you end up with the potential for the development of El Nino. So right now we’ve seen it for just about a third of the year. Like Ray was mentioning, as we get into early July, we should hit that threshold and El Nino will be established.

JC: Let’s say it does. What does hot water do to these hurricanes?

MC: The main fuel source for tropical cyclones is that warm water. They need water temperatures of 80 degrees Fahrenheit or higher, so when we get warmer than normal water, there’s more energy in the water, there’s more energy available to feed storms, to begin their generation. Once they form enough there to continue to feed them, they last a bit longer, maybe get stronger than usual.

JC: Does El Nino have any influence on the track of the storm? Would having El Nino in place put storms farther south or north?

RT: It certainly can have an effect on the track of storms. What we see with El Nino is the warm water that’s typically sandwiched right near the equator extends further to the north. Because of that, because that warm pool gets closer to the islands, it allows storms to maintain their strength and possibly gain a little latitude closer to the islands. The second part is that El Nino tends to reduce our trade winds. Trade winds are one of the natural protections that we have. Normally trade winds blow from the northeast, keeps tropical cyclones to our south and safely moving toward the west. In a lack of trade winds, that allows some systems to curve up to the north. It’s something we saw with Iniki and Iwa, we saw a lack of trade winds and that allowed these storms to curve up toward the Hawaiian islands.

hurricane graphic tropical cyclone graph

JC: So two out of the three hurricanes that have affected Hawaii within the past 50-plus years have been El Nino years as well?

MC: Yes. So both Iwa and Iniki, the last two in particular, were during El Nino years. El Nino doesn’t necessarily mean that we’re guaranteed to have something impacting Hawaii. Since Iniki, we’ve had four or five El Nino episodes in the Central Pacific, but no impacts to the state. So El Nino isn’t a guarantee but the last two direct impacts from a hurricane came during El Nino years.

JC: I do want to mention one more thing. It’s important that we have this hurricane forecast for the season, but it does not mean that it will directly affect Hawaii or even come close, because the Central Pacific is a very large body of water.

RT: That’s correct. One of the things that protects Hawaii is that we’re a really small target. If you look at the Atlantic and the East Coast, which gets a lot of press from hurricanes, if a hurricane is moving toward the East Coast, if it misses Florida, it might hit further up the coast. If it misses South Carolina, it may hit North Carolina. So there’s a large stretch of land in its way. Here in the Central Pacific, you have the hurricane, maybe the size of your fist, and the Hawaiian islands the size of a fingernail, and you have to get those two to line up. So we’ve had a lot of near misses within 100 miles and most residents wouldn’t even know that a hurricane was nearby.

JC: Well, we always hope for the best in a hurricane season. Gentlemen, thank you for stopping by.

For more information, visit the Central Pacific Hurricane Center’s website.

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