Tropical Storm Madeline and Hurricane Lester continued to move toward Hawaii on Sunday, raising the chances of a rain-soaked Labor Day weekend.

At 5 p.m. Sunday, Madeline was 800 miles east- southeast of Hilo and about 1,005 miles east-southeast of Honolulu, moving west- northwest at about 10 mph and packing 65 mph winds.

Forecasters said Madeline could strengthen into a hurricane by today before gradually weakening as it continues to approach the islands. The storm is expected to take a turn to the west late today.

If the storm continues on its current track, humidity and showers ahead of Madeline’s center will begin arriving Tuesday over Hawaii island and Maui and then spread to the other islands. The center of the storm could move near the Big Island on Wednesday, bringing tropical storm conditions.

That would potentially coincide with President Barack Obama’s scheduled visit to Hawaii for the World Conservation Congress. The convention, scheduled for Thursday to Sept. 10, is expected to bring in several other dignitaries as well as heightened security and road closures around the Hawai‘i Convention Center and the Neal S. Blaisdell Center.

Meanwhile, Lester was 1,875 miles east of Hilo and 2,060 miles east-southeast of Honolulu at 5 p.m. Sunday. The storm had 85 mph winds and was moving west at 14 mph. Forecasters said Lester could reach Hawaii by Labor Day weekend if it continues on its current path.

Forecasters cautioned, however, that the forecast tracks for both storms could change significantly in the next few days and that it is still not possible to predict exactly how and when the storms will affect the islands.

The National Weather Service said tropical storm watches might be posted in the next couple of days.

Forecasters added that the margin of error for predicting Central Pacific tropical cyclones can vary between 185 and 250 miles on the fourth and fifth days of the forecast track.

“There is a large degree of uncertainty with the speed, track and intensity of tropical systems like this, which can result in significant changes to the types of impacts we could see,” forecasters said.

Moderate tradewinds are expected to continue for the next few days as a high-pressure system persists north of the state. Wet weather could arrive as early as Tuesday as a surge of deep moisture moves across the state from the east, heralding the arrival of Madeline’s northernmost edge.