Weather update for Friday: Lala holding steady, tracking west-northwest, still forecast to become hurricane

Still a tropical storm as of the 11 p.m. Central Pacific Hurricane Center update Aug. 13, Lala is holding steady, tracking west-northwest on a path that now looks like the storm could make landfall — at least briefly — in the southern portion of the Big Island.

“Lala will … move directly over or just south of the Big Island … on Saturday and pass just south of the rest of the island chain through Sunday,” said the National Weather Service Honolulu forecast office’s 11 p.m. overview. “Do not focus on the exact forecast track or intensity of Lala at this time, and be prepared for changes in future forecasts.”

The tropical storm remains forecast to become a hurricane as it continues to steadily strengthen and approach the island by early Saturday.

A hurricane warning continues for Hawai‘i County, while a tropical storm watch is in effect for Maui County. Central Pacific Hurricane Center forecasters say preparations to protect life and property on the island should be rushed to completion.

The storm was about 455 miles east-southeast from Hilo, or about 670 miles east-southeast of Honolulu, with sustained winds of 60 mph, with higher gusts, and moving west-northwest at just 10 mph.

Tropical storm force winds extended outward from the storm’s center up to 275 miles.

Lala is forecast to keep moving in that direction during the next several days, with some slowing in forward speed as it nears the Big Island before picking up speed later this weekend.

Residents and others elsewhere throughout the main islands and in Papahānaumokuākea Marine National Monument should keep monitoring Lala’s progress.

Expected hazards from Lala

• Wind: Hurricane conditions are expected by early Saturday on the Big Island, with tropical storm conditions possible in Maui County by later the same day. Wind speeds atop and on windward sides of slopes and mountains are often up to 30% stronger than near-surface winds, and in some elevated locations could be even greater. It is important to note that the mountainous terrain of the islands can produce localized areas of highly enhanced and damaging winds, even well away from the tropical cyclone’s center.

• Rainfall: Heavy rainfall will begin today to impact the Big Island, then spread west during the weekend. Rainfall totals of 8 to 12 inches are forecast around Maui and the Big Island, with maximum totals of 25 inches possible in some locations on the Big Island. Rainfall totals of 4 to 6 inches, with maximum amounts of 8 inches, are forecast throughout the remainder of the island chain. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. A flood watch is already in effect through late Saturday night for portions of the Big Island and Maui County because of the possibility of flash flooding. While the highest rainfall amounts will be focused over windward areas, leeward areas will also have significant flood risk.

• Surf: Swells generated by Lala are expected to reach east-facing shores of the state on Friday, spreading westward and building through the weekend. Large and dangerous waves, especially on the Big Island, are expected, with the greatest impacts along exposed windward and southern shores. This prolonged period of heavy surf could cause localized coastal flooding and significant beach erosion as well as life-threatening surf and rip current conditions.

• Storm surge: Combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. Water could reach up to 3 feet if the peak surge occurs at the same time as high tide The deepest water will occur along the immediate coast, where surge will be accompanied by large and dangerous waves. Surge-related flooding will depend on relative timing of the surg and tidal cycle, and can vary greatly over short distances.

• Isolated tornadoes: Twisters are possible around the Big Island, which could hinder execution or emergency plans, cause damage as well as power and communications disruptions. Roofs peeled off buildings, chinmeys toppled, mobile homes pushed off their foundations or overturned, large tree tops and branches snapped off, shallow-rooted trees knocked over, moving vehicles blown off roads and small boats pulled from moorings are all potential impacts from a tornado if one should strike.

Visit the National Weather Service Honolulu forecast office website to check on specific storm details for expected storms hazards your area plus any advisories, watches or warnings among additional forecast information.