Unpredictable weather will be the norm in the islands over the next few months as the worst drought in the country gives way to an unusually wet winter beginning in January, weather officials predicted yesterday.

The sudden transition from drought to heavy rains could unleash flash flooding and even lightning strikes that might once again knock out island-wide power grids, said Kevin Kodama, a hydrologist with the National Weather Service.

Kodama and Jim Weyman, director of the National Oceanic and Atmospheric Administration’s Central Pacific Hurricane Center, hesitated yesterday to commit to what might happen because of this year’s La Nina conditions, which drop ocean surface temperatures by 2 to 3 degrees along the equatorial Pacific and make forecasts difficult.

"Unlike an El Nino, with a La Nina you have a lot more uncertainty involved," Kodama said.

He even hesitated to predict how long La Nina conditions might last.

La Nina, or "the little girl" in Spanish, is the opposite of El Nino, manifested by warmer-than-usual tropical ocean conditions that typically generate spectacular North Shore winter waves.

In May, Weyman forecast that the Central Pacific would see only four to five tropical cyclones, which is considered "below-normal activity" during the hurricane season, which runs through Nov. 30.

Instead, tropical cyclones have yet to appear.

"Yes, it’s been a quiet season," Weyman said.

The unpredictable, upcoming winter has state Civil Defense officials worried that dried out areas will suddenly become deluged by flash floods and even landslides.

"We get a little anxious when we have long dry spells and now, here comes the rain," said Ed Teixeira, state Civil Defense vice director. "We have seen dry spells followed by horrendous events, such as the Sacred Falls rockslide that resulted in fatalities. … In 2000, we had the Waimea rock slide that followed record rainfall."

Hawaiian Electric Co. spokesman Darren Pai said HECO customers should always be prepared for the possibility of power outages in stormy weather.

Oahu’s 2008 island-wide outage "was due to a very rare set of conditions," Pai said.

However, he urged everyone to have an emergency kit at home.

"Whether it’s high winds or other conditions, it’s always a good idea for people to be prepared to be without power whenever there’s a storm approaching," he said.

Parts of the Big Island and Maui County continue to suffer through the worst drought in the nation, Kodama said.

But a sudden onslaught of rain won’t be welcomed by farmers and ranchers, said Janelle Saneishi, spokeswoman for the state Department of Agriculture.

"Too little rain is not good and too much rain is not good, not all at once," Saneishi said. "Especially coming off of a period of drought. Heavy, heavy rains would be a major problem."

And La Nina won’t help surfers hoping for a spectacular big wave season.

"La Nina is usually not a good thing," said Kaz Sano, who operates a surf website for children, novusswell.com. "When the water temperature gets colder, you just don’t get good swells."

Rick Grigg, a North Shore surf legend and oceanography professor at the University of Hawaii, said El Nino winters typically bring big, glassy surf.

"The water’s smooth in El Nino years," Grigg said. "It’s really clean and sweet for surfing. With a La Nina, you get more wind, it’s choppier and colder."

With 25 to 30 swells each winter, however, Grigg said, "You’re still going to get some 25-foot waves, easy. The surfers will have plenty to keep them busy. But I would say this year will be below average, probably not the greatest year."

Jodi Wilmott pays attention to El Nino and La Nina years as the spokeswoman for The Quiksilver in Memory of Eddie Aikau and Vans Triple Crown of Surfing tournaments.

She’s hardly discouraged about the prospects for a good surf season this winter.

"For the La Nina years, you’re looking at one or two extra large episodes as opposed to last year, when we had a dozen or more," Wilmott said. "But it only takes one and you have an Eddie Aikau Quiksilver event in a La Nina year."

Wilmott lives in Waialua and knows what La Nina winters mean for the North Shore of Oahu:

"Red dirt becomes a very popular color," she said. "When we hear La Nina, it’s ‘Oh, God, here comes another muddy winter.’ But a bad day in Hawaii is still better than most days anywhere else."