From NWS Honolulu:
HURRICANE MADELINE LOCAL STATEMENT for Big Island North and East
Issued: 30 Aug 2016 12:27 pm HST
MAJOR HURRICANE MADELINE TRACKING WESTWARD TOWARDS THE HAWAIIAN ISLANDSHURRICANE WARNING REMAINS IN EFFECTNew information
Details for local weather and impacts from madeline have been added.
Hurricane madeline is forecast to approach the state from the east through tonight, with the latest Central Pacific Hurricane Center forecast bringing madeline very close to the Big Island Wednesday through early Thursday. Based on the current track, strong damaging winds and very heavy rainfall is likely across the Big Island. Any shift in the track to the north, could result in tropical storm conditions spreading into Maui county on Thursday. In addition to the heavy rain and strong winds, large and damaging surf is expected along east facing shores of the Big Island and the island of Maui. Surf will begin to rise this afternoon, and reach dangerous levels later tonight through Wednesday night.
Probability of tropical storm/hurricane conditions
The chance for hurricane conditions at Hilo is 10 percent, Kailua-Kona is 6 percent, and South Point is 23 percent. Also, the chance for tropical storm conditions at Hilo is 78 percent, at Kailua-Kona is 68 percent, and at South Point is 90 percent. These values are trending slightly up for the southern portion of the Big Island. The onset of tropical storm conditions could start as early as Wednesday morning. The onset of hurricane conditions could start as early as Wednesday evening.
Depending on the exact track of madeline, some areas could see winds as high as 60 to 80 mph with stronger gusts possible.
Winds this strong would be very dangerous and airborne debris could produce widespread damage. Any loose outdoor items would become projectiles, causing possible injury. Other possible wind damage would include, downed large trees and power lines, and significant roof and structure damage, especially to weaker structures.
Extensive damage to power lines and poles could result in widespread power outages that could last from several days to weeks.
Storm surge and storm tide
Large and damaging surf is expected along east facing shores. Surf will build this afternoon, and peak at 15 to 25 feet tonight through Wednesday night. Depending on the exact track of madeline, storm surge will range from 1 to 4 feet. The combination of storm surge and wave runup may cause significant coastal flooding and damage to coastal properties and infrastructure, including roadways. Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling.
A flash flood watch is in effect. Deep tropical moisture associated with the madeline will begin to impact the Big Island Wednesday morning, bringing the threat of heavy rainfall and flooding through late Thursday. Total rain accumulations of 5 to 10 inches are possible, with isolated maximum amounts near 15 inches, especially over windward portions of the Big Island. This rainfall may lead to dangerous flash floods and mudslides. Refer to the watch for more details.
For those under a warning, your preparations to protect life and property should be rushed to completion. In a tropical cyclone, conditions can change quickly. Evacuate if directed to do so by local officials, or if your home is vulnerable to high winds or flooding. Cancel any beach activities until further notice. Persons living near the shore should be prepared to evacuate quickly should building surf threaten.
People under a watch should continue making preparations and listen for possible warnings.
Closely monitor NOAA weather radio or other local news outlets for official storm information. Listen for possible changes to the forecast.
Cover and secure windows and brace garage doors. Loose objects such as lawn furniture, garbage cans, and other items should be secured or stored indoors.
If evacuating, leave as soon as possible. Do not get stuck on the roads when the dangerous winds and heavy rains arrive.