UPDATE 11 P.M.
Tropical Storm Barbara is expected to become a post-tropical cyclone on Saturday.
The National Hurricane Center said Barbara was 1,150 miles east of Hilo at 11 p.m. Friday.
Barbara is moving toward the west near 15 mph, with maximum sustained winds near 50 mph. It will continue to weaken as it heads west for the next couple of days.
The National Weather Service in Honolulu said light trade winds will continue into early Saturday with a few windward showers.
“The diminished trade wind flow will possibly allow a few interior and leeward showers to develop again on Saturday afternoon. Trade winds will then strengthen Saturday night and Sunday, and limited windward showers are expected as the air mass briefly dries slightly,” weather officials said.
Tropical Storm Barbara is fading and expected to become a post-tropical cyclone later tonight.
The National Hurricane Center said Barbara was 1,235 miles east of Hilo. Winds at 60 mph this morning have decreased to 50 mph as of this afternoon.
Barbara is moving toward the west at about 14 mph and a continued westward motion with an increase in forward speed is expected in the next couple of days.
“Continued weakening is forecast during the next 48 hours and Barbara will likely become a post-tropical cyclone later tonight,” forecasters said.
The National Weather Service in Honolulu said the remnants of Barbara will bring breezy trade winds Sunday night through Monday night, with the winds easing Tuesday. Forecasters said rainfall of about 2 inches or greater “will begin to move into the Big Island Sunday night, then spread eastward across the rest of the island chain Monday and Monday night. Drier air will then begin to work into the region from east to west Tuesday and Tuesday night.”
A high surf advisory has been issued for east-facing shores of the Big Island and Maui. A large east swell generated by Barbara is expected to spread across the eastern end of the island chain through Saturday morning. Surf will increase to 6 to 10 feet by Saturday morning and build to 8 to 12 feet Saturday night and Sunday.
Meanwhile, an area of low pressure in the eastern Pacific is expected to form into a tropical storm early next week. It was located hundreds of miles south of the southern tip of the Baja California Peninsula and is moving west-northwest.
Tropical Storm Barbara, once a powerful Category 4 hurricane, is forecast to dissipate to a remnant low by Saturday as it enters the Central Pacific.
The National Hurricane Center said Barbara was 1,330 miles east of Hilo with maximum sustained winds of near 60 mph and moving west-northwest at 13 mph as of 11 a.m. today.
“Continued weakening is forecast during the next 48 hours, and Barbara is forecast to become a post-tropical cyclone on Saturday,” forecasters said.
Tropical storm-force winds extend up to 140 miles from the storm’s center.
The National Weather Service in Honolulu said Barbara should approach the eastern islands as a post-tropical remnant low Sunday night, then dissipate Monday or Monday night, bringing breezy conditions to the state, and periods of wet weather to mainly windward areas.
”Breezy trade winds appear likely Sunday night through Monday night, with the trades easing to moderate and locally breezy levels Tuesday and Tuesday night,” weather service forecasters said. “Some of the rainfall could be heavy, particularly over the Big Island and windward terrain of the remaining islands, with an isolated thunderstorm not out of the question.”
Drier and more typical trade wind weather will return during the middle and latter part of next week.
Barbara will also bring high surf to the islands beginning today, starting with the eastern islands. Forecasters expect advisory-level surf for the Big Island and Maui tonight into Saturday, then for all east facing shores by the end of the weekend.
Today will be mostly sunny, with isolated showers. The heat index, a reflection of temperature and humidity combined, is expected to reach 95 this afternoon in Honolulu and Kahului.
A record high of 93 degrees was set at Kahului on Thursday, the Fourth of July, breaking the old record for the date of 90 set in 2018.
Maui County officials issued an advisory today saying that affects from Barbara, including flash flooding and high surf, are expected to begin Sunday evening and last until the middle of next week.
They said residents should expect 2 to 4 inches of rain, primarily in East Maui, and 1 to 3 inches across the rest of the county. Surf from 8 to 12 feet for east-facing shores on Maui and Molokai, and 15 to 30 mph winds are also forecasted.
“Residents should prepare their household by making an emergency kit, creating a plan and staying informed,” Maui County officials said.
Forecasters said moisture from Barbara should clear the islands to the west late Tuesday into Wednesday, with moderate to locally breezy trade winds continue. More seasonal trade wind weather is in store for the later part of next week.
Elsewhere in the eastern Pacific, another weather system hundreds of miles south of Baja California has an 80% chance of forming into a tropical cyclone over the weekend as it moves west-northwest toward the Central Pacific, the National Hurricane Center said today. If it grows into a tropical storm, it will be called Cosme.