Tropical Storm Wali weakened some overnight Friday, however, the storm continues to pack 40 mph winds as it marches toward the Hawaiian Islands.
The system, located about 925 miles east-southeast of Hilo and moving northwest around 12 mph as of 5 a.m. Friday, is expected to continue to weakening and ultimately dissipate well before the weather arrives around 6 p.m. Saturday, Central Pacific Hurricane Center forecasters in Honolulu say. Tropical storm force winds currently extend outward 70 miles.
Although the storm is expected to be downgraded to a post-tropical remnant low during the coming 48 hours, the forecast track does put the Big Island smack in the way of flooding and thunder storms expected to last through Monday. Projected winds could reach 35 miles per hour.
Wali follows the remnants of Tropical Storm Fausto and associated disturbances that dumped 6.7 inches at Hilo Airport over several days and brought rain to leeward areas as well early this week. Wali is expected to have higher rainfalls over much greater areas of the state, said Chris Brenchley, acting warning coordination meteorologist with the Central Pacific Hurricane Center.
At this point, that amount is hard to quantify exactly, but should equate to at least several inches.
“It’s a lot more moisture and potential for thunderstorms than what was dealt with on the Big Island,” Brenchley said.
Wali — the basin’s first named storm of the season — is forecast to reach peak strength around noon Friday with 60 mile-per-hour winds, then weaken rapidly as the system runs into cooler waters and increased wind shear.
“Rain is definitely a concern,” said Hawaii County Civil Defense Director Darryl Oliveira. “The ground is saturated in East Hawaii, and heavy downpours could cause a problem. We’ll continue to monitor, especially as we get into Saturday.”
The storm is currently over 80-degree water. That temperature is marginal for supporting a storm, Brenchley said. In its path are 75-degree waters, which will dampen formation.
“The major impact is shear that can tear a storm apart pretty quickly,” Brenchley said. “We expect rapid weakening after Friday.”
From Friday onward, Wali’s track shifts slightly to the west, putting it directly on course for the Big Island. That shift is due to the trade winds beginning to steer the weakened system, Brenchley said.
Civil Defense has been coordinating with the National Weather Service and engaging in twice-daily briefings with the agency, Oliveira said. As the system approaches, residents should monitor their radios for Civil Defense messages, he said.
Elsewhere in the Central North Pacific Ocean Basin, forecasters do not expect tropical cyclone formation through early Sunday.