UPDATE: 5 a.m.

Barbara strengthened to a Category 4 hurricane overnight and could continue growing stronger.

Centered about 1,080 miles southwest of the southern tip of Baja California and 1,939 miles east-southeast of Hilo, Barbara is packing maximum sustained winds of 130 mph while moving west-northwest at 14 mph, according to the National Hurricane Center.

A decrease in forward speed is expected to begin today, followed by a turn toward the northwest in a day or two, weather officials said.

Although some additional strengthening for Barbara is possible today, it’s expected to begin weakening Wednesday through Thursday.

Hurricane-force winds extend outward up to 25 miles from the center and tropical-storm-force winds extend outward up to 185 miles.

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Hurricane Barbara formed Monday morning far out in the eastern Pacific and quickly grew to a Category 2 storm by evening.

It is expected to grow into a major hurricane by today before weakening later this week as it approaches the Central Pacific.

The National Hurricane Center in Miami said at 5 p.m. Hawaii time Monday that Barbara had maximum sustained winds of 100 mph and was moving west at 15 mph. It was centered 1,010 miles southwest of the southern tip of Baja California and less than 2,500 miles east-southeast of Hilo.

“Rapid strengthening is forecast to continue for the next day or so, and Barbara is expected to become a major hurricane by (tonight),” forecasters said. “A weakening trend is forecast to begin Wednesday night or on Thursday.”

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Barbara is projected to hit its peak far from land as a Category 4 storm with maximum sustained winds of 140 mph by Wednesday, before it drops to a tropical storm with 50 mph sustained winds Saturday as it enters the Central Pacific region, still hundreds of miles away from the Big Island.

Hurricane-force winds extended up to 25 miles from the center of the storm late Monday, and tropical storm-force winds extended up to 160 miles, they said.

Barbara is the second named tropical cyclone of the 2019 Pacific hurricane season. The first one, Alvin, briefly gained hurricane strength late last week before dissipating as expected Saturday.

While it is too early to say how Barbara might affect Hawaii’s weather next week, a high-surf advisory was extended for all south-facing shores through 6 a.m. this morning.

The National Weather Serv­ice in Honolulu said surf as high as 6 to 9 feet was expected to continue through Monday night. The initial advisory had been set to expire at 6 p.m. Monday.

Besides strong, breaking waves and shore break, strong rip currents were expected to make swimming difficult and dangerous. Beachgoers, swimmers and surfers were advised to exercise caution and heed all advice given by ocean safety officials.

A small-craft advisory also remains in effect for Alenuihaha Channel and Big Island leeward waters through 6 p.m. today.

Forecasters expect the tradewind weather pattern to hold over the next few days.

Winds, however, will become lighter Wednesday through Friday, and over the Fourth of July holiday, as a trough of low pressure approaches from the northwest. The trades are expected to return next weekend.