NOAA's climate prediction center has issued an El Nino watch, which here in Hawai'i could mean a return to drought-like conditions and an increase in hurricane threats.
Climate experts are saying there are no guarantees, but they believe there is a 50% chance El Nino will develop over the next six months.
El Nino conditions are declared when the average sea surface temperatures in the eastern Pacific are at least 0.5°C above average for three consecutive months. These abnormally elevated sea surface temperatures allow for the atmosphere to warm and provide instability.
"Every El Nino is different. We can't be definitive about number one, whether or not it's going to happen and number two, precisely what the impacts are going to be. We'll have to keep an eye on it over the next couple of months and see how it develops," said Robert Ballard, a Science & Operations officer with the National Weather Service.
Officials say the watch issued by NOAA is primarily designed to give decision makers a heads-up for long-term planning, especially when it comes to water resource management should El Nino conditions lead to a warm, dry winter.
"There is a possibility that this sort of wet pattern that we've been in through the last winter which has brought really beneficial rains to parts of Maui and the Big Island that really needed it we could possibly be looking at a situation where we start to dry out again, especially over those Leeward areas which desperately need the rain," Ballard said.
Experts say Hawai'i has been very lucky to have avoided major hurricane events in recent years, but cautions some of the worst tropical cyclones have occurred during El Nino years -- like Hurricane Iwa and Hurricane Iniki.
"Some El Nino years we've seen a lot of hurricanes develop, but they all go harmlessly south of the islands and they just go east to west and they stay on their merry way. That's what happens a lot of the time, but then you can get into situations like Hurricane Iwa or Hurricane Iniki which recurve. Especially those later season hurricanes, when you get into the middle to latter half of the season, and the islands can get into a greater threat," explained Ballard.
"We haven't made any forecasts for the tropical cyclone season yet. We're still months away from doing that and we'll have to wait and see how this El Nino pans out -- and even if it pans out -- before we can make any sort of forecast about what we think is going to happen specifically in Hawai'i," Ballard said.
The last El Nino was late 2009/early 2010, while the last one NOAA predicted was in 2012 but never quite materialized.