Updated: July 5, 7:28 p.m.

Maui and Oahu officials are advising residents to remain alert as Tropical Storm Barbara, although weakened from hurricane strength, could still bring heavy rains, flooding, high winds and high surf to the islands as early as Sunday.

As of 5 p.m. Friday, the National Weather Service reported the center of Tropical Storm Barbara was located about 1,230 miles east of Hilo, with maximum sustained winds of about 50 mph after reaching powerful Category 4 strength earlier this week.

The weather service said Barbara will likely become a post-tropical storm later Friday night.

"While it appears Barbara will continue to dissipate as it heads toward our islands, everyone needs to remain vigilant and prepared," said Honolulu Mayor Kirk Caldwell in a statement Friday.

Hawaii is in the midst of its annual hurricane season. Forecasters say there is a higher than normal chance of a more active season this year than last year. While Barbara is no longer a hurricane, city officials said the storm is a reminder for residents to make prepare for an emergency.

Maui County officials said the effects of Barbara is forecast to last through the middle of next week. In a news release, they advise residents to prepare an emergency kit and conserve water during heavy rain and wind events since these can cause outages affecting water distribution and treatment systems.

Barbara is expected to further degenerate into a remnant low system within the next two days as it heads in the general direction of the islands.

This is a developing story. Please return for updates.