Here we go again.
Hawaii Island should brace for significantly more rainfall, wind and risk of flash flooding this weekend as Tropical Storm Wali sets sights on the archipelago.
The system, located about 1,000 miles east-southeast of Hilo and packing 45 mph winds, is expected to dissipate well before the weather arrives around 6 p.m. Saturday. But the forecast track does put the Big Island smack in the way of flooding and thunderstorms expected to last through Monday. Projected winds could reach 35 miles per hour.
The remnants of Tropical Storm Fausto and associated disturbances dumped 6.7 inches at Hilo International Airport over several days and brought rain to leeward areas early this week. Expect Wali 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 forecasted to reach peak strength around noon today with 60 mph winds, then weaken rapidly as it 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.”
Storm force winds extended 90 miles from the center of the system on Thursday afternoon. Wali was steering northwest at 9 mph, 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 today onward, Wali’s track shifts slightly to the west, putting it directly on course for the Big Island. That shift is because of 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.
Email Bret Yager at firstname.lastname@example.org.