By Jonathan Kaminsky
(Reuters) - A tropical storm with the potential to trigger serious flooding and mudslides was bearing down on Hawaii on Monday and authorities there cautioned residents and tourists to stay inside and off the roads.
Tropical Storm Flossie was expected to strike the Big Island and Maui on Monday evening, with waves along the eastern shores of those islands likely to reach as high as 18 feet, according to the National Weather Service.
"This shouldn't be taken lightly. It's not just a rain cloud," said Brian Miyamoto, spokesman for the Hawaii State Civil Defense. "Try to prevent non-essential driving or going outside if you don't need to."
As of 11 a.m. local time (2300 GMT) the storm was about 65 miles from the Big Island — the easternmost island in the chain — traveling at 18 miles per hour with sustained wind speeds of about 40 miles per hour.
"The threat for strong winds is diminished somewhat but there's still the potential for some heavy rain and flooding," said Mike Canton, a meteorologist with the National Weather Service in Honolulu. "The course has it hitting right over the state."
The state's airports were still open but some airlines were cancelling flights, Miyamoto said. Along with some of the state's harbors, at least 19 state parks were closed on Monday on the Big Island, Maui, and Kauai, he said.
The Hawaii State Civil Defense was on full activation and operating on 12-hour shifts, Miyamoto added.
In anticipation of the storm, Hawaii Governor Neil Abercrombie signed an emergency proclamation on Sunday freeing up disaster funds for emergency supplies, cleanup efforts and state worker overtime pay. He also called the Hawaii National Guard to active duty to ensure it was ready to help.
In addition to nine shelters opened on the Big Island, another 10 are being set up in Honolulu County, said Honolulu Mayor Kirk Caldwell, who urged residents and tourists to have a seven-day supply of food, water and batteries.
"Take it seriously," he said. "In Hawaii, we always plan for the worst. Most of the time it doesn't turn out as bad."
(Editing by Cynthia Johnston and Paul Simao)