It’s time to batten down the hatches.
Hurricane Iselle was forecast to arrive Thursday on the Big Island as a tropical storm packing at least 45 to 55 mph sustained winds, gusts to 65 mph and 5 to 8 inches of rainfall. High surf ahead of Iselle is slated to hit windward shores today, and Tropical Storm Julio could bring more wind and rain Sunday.
Iselle is predicted to bring widespread flooding beginning Thursday afternoon and continuing through Friday. The National Weather Service placed the island under a tropical storm watch and the entire island chain under a flash flood watch effective from 4 a.m. Thursday to 6 a.m. Saturday.
Residents are urged to prepare for power outages, potential mudslides and flash flooding. They should also secure loose objects in their yards and have supplies of food, water and other essentials on hand as the state faces potentially the worst weather in more than two decades.
A 2.5-foot high tide at 12:30 p.m. Wednesday combined with surf heights of 10 to 20 feet on the windward side will bring a potential for coastal flooding ahead of Iselle, and even higher, potentially damaging surf is expected Thursday, according to an NWS warning.
Evacuations of low-lying coastal areas are possible, and inhabitants of those regions should be prepared to get out quickly, officials say. The NWS is urging residents to monitor media outlets, and Hawaii County Civil Defense is issuing periodic updates on radio stations.
Located 900 miles east of Hilo on Tuesday evening, Iselle was circulating 100 mph winds and tracking west-northwest at 13 mph. The Big Island is directly in its projected path. The system was expected to weaken as it moves into increased vertical wind shear and drier air east of the islands. Hurricane force winds extend 30 miles from the center, and tropical storm force winds extend 115 miles in radius.
Forecast models at the Central Pacific Hurricane Center call for a 52 percent chance of tropical storm force winds in Hilo, a 46 percent chance for Kona and a 39 percent chance for South Point. Tropical storm force winds range from 39 to 73 mph. Hilo has a 5 percent chance and Kona has a 3 percent likelihood of hurricane force winds from the system.
Tropical storm Julio could deliver a second punch Sunday. There is a lot of uncertainty about its exact course and the amount of rainfall and wind it will bring, NWS meteorologist Eric Lau said. Julio was located 1,210 miles southwest of the southern tip of Baja California and tracking west at 13 mph, with 65 mph sustained winds. It was expected to become a Category 1 hurricane today.
Residents and visitors should stay off beaches. Rough seas to 15 feet are forecast for windward waters, and West Hawaii waters could remain treacherous even after Iselle has passed.
“The ocean is going to be erratic. The surf is going to be rough,” said Lau. “Undertows, rip tides and currents could be quite hazardous.”
The 403rd Wing Hurricane Hunters were slated to fly through Iselle and take measurements Tuesday evening and Wednesday. The Biloxi, Miss., team was set to deploy dropsondes to measure wind speed, temperature and barometric pressure.
“We’re looking for the low pressure center,” said Master Sgt. Brian Lamar, public affairs officer for the 403rd Wing. “We’ll have an entire column of data from 10,000 feet down to the ocean surface.”
Other businesses and individuals were gearing up for the storm as well.
The parking lot at Costco in Kailua-Kona was packed Tuesday afternoon and residents lined up to fill their gas tanks. Shelves for water and other liquids were quickly being emptied from grocery stores. At Longs Drugs in Hilo, canned goods and water were in high demand. The store was running low on water Tuesday but had more set to arrive today, a manager said. At Ace Hardware &Crafts in Kailua-Kona, people were lining up to stock their propane supply, assistant manager Corinna Oyama said.
Target Senior Team Lead Mandi Goddard said Tuesday afternoon the store already sold out of less expensive brands of water. Employees at the Kailua-Kona store were restocking a water display with a name brand, and moving temporary displays of toilet paper, rice and water from one part of the store to another. Customers also were grabbing batteries and Spam. Store employees were in contact with vendors Tuesday, to see if deliveries scheduled later this week could be moved up.
Reporter Erin Miller contributed to this story.
Email Bret Yager at email@example.com.