Tropical Storm Celia formed overnight and is expected to intensify as Hurricane Blas moved over cooler waters.

Celia, packing maximum sustained winds of 45 mph, was about 715 miles south-southwest of Baja California late this morning. It was moving west-northwest at 6 mph.

Forecasters with the National Hurricane Center said Celia may become a hurricane by Sunday. But its development was hindered because the ocean is slightly cooler after Hurricane Blas passed through the area.

Celia is following a similar path as Blas.

Meanwhile, Blas is no longer a major hurricane and is expected to rapidly weaken as it moves northwest at 9 mph and leaves an area of warmer water. The storm was about 1,365 west of Baja California, roughly 1,700 miles east of the Big Island, with sustained winds of 85 mph at 11 a.m. HST, compared to 100 mph at 5 a.m.

Blas is forecast to weaken to a tropical storm by Saturday and to below tropical storm strength by Sunday.

Surf generated by Blas when it was a major hurricane is expected to reach Hawaii today, bringing waves with heights of 3 to 5 feet today and 4 to 6 feet Saturday with higher sets. The wave heights could reach advisory levels of 8 feet.

Surf on south shores is already at advisory levels from a storm near New Zealand last week. Wave heights of 6 to 9 feet are expected on south shores of all islands. The surf is expected to peak tonight.

Blas may also bring an increased chance of showers and higher humidity as what’s left of the storm passes near the islands late next week.

Remnants of former Tropical Storm Agatha are expected near Hawaii this weekend. What’s left of the storm could bring lighter tradewinds and increased windward showers Saturday night into Sunday and Monday as it moves west over the state.

Forecasters said it’s too early to say what effect, if any, Celia will have on Hawaii’s weather.