It's too early to say how the tropical depression that dumped heavy rains on parts of Puerto Rico and the Dominican Republic Saturday might affect Charleston later this week, but forecasters don't expect the impact to be great at this point.

"There is a lot of uncertainty at this point," said Bob Bright, a meteorologist with the Charleston office of the National Weather Service. "We're not too concerned, especially considering we're on the west side and storms are usually weaker on the west side."

The weather service's forecast for Charleston says tropical storm conditions are possible Wednesday night.

Bright said he expects the bad weather to pass well offshore, kicking up some rough waves that might cause some beach erosion and minor flooding.

On the other hand, the system's course could change, and it bears watching over the next few days.

"We're still in that cone of uncertainty," he said. "It's too early to make a guess."

The system is expected to strengthen into a tropical storm Sunday as it passes over or near the central Bahamas.

The immediate forecast for the Charleston area calls for lower temperatures, a welcome relief from the searing heat of the past few days.

The mercury is not expected to rise above the high 80s through Wednesday.

The temperature reached 99 at Charleston International Airport on Saturday, breaking a record of 98 set in 1983 and 1968, according to the weather service.

The humidity made it feel closer to 107.

Sunday's forecast calls for highs in the upper 80s, with mostly cloudy skies and a 30 percent chance of showers and thunderstorms.

Reach Dave Munday at 937-5553.