Nolo strengthens as it turns north toward Big Island; hurricane conditions possible by Friday night

Tropical Storm Nolo is strengthening and making a turn to the north as of the 11 p.m. advisory update from national hurricane forecasters.

Maximum sustained winds were up to 50 mph, with higher gusts, as the storm moved north at an even slower rate of just 2 mph, churning about 285 miles south of South Point.

A hurricane watch remains in effect for the Big Island.

A general north to north-northeast motion is expected to continue through Friday, followed by a sharp westward turn by Saturday when Nolo is within the vicinity of the Big Island.

Nolo is forecast to become a hurricane by Thursday night and could become a major hurricane by the weekend.

Tropical storm force winds extended outward up to 80 miles from the storm’s center as of Wednesday night.

Nolo is expected to make a sharp westward turn Friday night into Saturday; however, some guidance models shifted the storm slightly northward, bringing the it even closer to the Big Island.

National Hurricane Center track forecast still shows Nolo passing south of the Big Island on Saturday before continuing westward, south of the smaller Hawaiian Islands, through the latter portion of the weekend.

“However, considerable uncertainty remains regarding the influence of [a] deepening upper-level trough on Nolo’s track, as well as the timing and strength of [a] subtropical ridge rebuilding north of the cyclone,” said the 11 p.m. forecast discussion. “Even relatively small differences in the evolution of these steering features could significantly alter the timing and location of Nolo’s [expected] sharp westward turn and, ultimately, how close its center passes to the Big Island.”

A track closer to the Big Island could also result in interactions with the island’s terrain that could further influence the cyclone’s subsequent motion.

“Given these uncertainties, confidence in the track forecast remains lower than normal,” the forecast said.

Hazards likely to impact land

WIND: Hurricane conditions are possible in the watch area starting as early as Friday night.

RAINFALL: Tropical Storm Nolo will produce rainfall totals of 15 to 20 inches around the Big Island. with maximum amounts of 35 inches. This rainfall could produce catastrophic life-threatening flooding and mudslides, especially in areas of steep terrain mainly in windward and southeast locations. Bands of intense showers and thunderstorms associated with Nolo will reach the Big Island as early as Thursday.

STORM SURGE: The combination of dangerous storm surge and tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach 1 to 3 feet above ground in some locations if peak surge occurs at the time of high tide. The deepest water will occur along the immediate coast near and to the right of the landfall location, where the surge will be accompanied by large and dangerous waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.

SURF: Swells generated by Nolo are expected to reach exposed east- and south-facing shores as well as southeast-facing shores of the Big Island by Friday, spreading westward and building through the weekend. These swells are likely to cause life-threatening surf and rip current conditions.

TORNADOES/WATER SPOUTS: Tornadoes and large waterspouts will be possible associated with Nolo, mainly over and near the Big Island, along and to the right of the track of the hurricane.

Additional sources of information

Disaster preparedness information: American Red Cross.

Appropriate preparations: Ready.gov.

For storm information specific to your area, including possible inland watches and warnings, monitor products issued by the National Weather Service Honolulu forecast office.

Also be sure to check out the “What Big Island residents need to know about Tropical Storm Nolo” at Big Island Now.

A flood watch also remains in effect through Saturday afternoon for the Big Island.