HONOLULU -- The Central Pacific Hurricane Center added a tropical storm warning for the Big Island of Hawaii ahead of Hurricane Flossie. The warning means tropical storm conditions are possible on the Big Island within 24 hours.

As if the approaching hurricane wasn't enough to deal with, people on the Big Island were shaken by an earthquake overnight.

The magnitude 5.4 quake that struck 25 miles south of Hilo caused a small landslide, according to a spokesman for Hawaii County Civil Defense.

There have been no reports of injuries or damage to buildings.

On Monday, Hawaii County Mayor Harry Kim declared a state of emergency for the Big Island. Kim urged residents to listen to local radio stations for announcements on evacuations, school closures and other storm related information.

"Our responsibility again is to make sure to give you the confidence that is the latest, and we will constantly cross check, even the simplest thing, we will cross check and cross check," Kim said.

Employees at emergency agencies are now on 24-hour standby ready to respond at a moment's notice, officials said.

The Big Island remains under a hurricane watch, which means hurricane conditions are still possible on Tuesday.

The National Weather Service in Honolulu also issued a flood watch for the Big Island through Wednesday ahead of Flossie. Rainfall of more than ten inches is possible in the Ka'u District of the Big Island, with 5 to 10 inches of rain expected on south and east facing slopes elsewhere on the island, forecasters said.

At 2 a.m. on Tuesday, the center of Flossie was located near latitude 16.6 north, longitude 153.5 west, or about 240 miles southeast of Hilo, and 440 miles southeast of Honolulu.

Flossie is moving toward the west-northwest at 15 mph. Maximum sustained winds are near 125 mph with higher gusts, making it now a Category 3 hurricane. Flossie strengthened into a Category 4 hurricane Saturday.

Hurricane force winds (74+ mph) extend 40 miles from the center, with tropical storm force winds outward up to 140 miles from the center, forecasters said.

The latest forecast track calls for Flossie to pass within 100 miles of the Big Island late Tuesday as a Category 3 hurricane. Central Pacific Hurricane Center director Jim Weyman said that a slight northward shift in track could potential bring hurricane conditions to the Big Island. Residents are being urged to follow directions from Civil Defense officials, and to prepare for strong gusty winds and heavy rainfall.

Stay with KITV for updates on Flossie here on TheHawaiiChannel.com and on Island Weather Now (Digital Channel 126).