Miami, Florida (CNN) -- Tropical Storm Matthew was strengthening Friday and could become a hurricane -- bringing heavy rains, flash floods and mudslides to Central America, forecasters said.
As of 5 a.m. ET Friday, the weather system was about 240 miles (390 kilometers) east of Puerto Cabezas, Nicaragua, and was heading west at 16 mph (26 kph). Its maximum sustained winds were at 50 mph (75 kph), according to the Miami, Florida-based National Hurricane Center.
Governments in Nicaragua and Honduras have issued hurricane warnings for portions of their coastlines, the center said.
Track-prediction maps indicate that Tropical Storm Matthew, the 13th named storm of the Atlantic hurricane season, will continue westward over the next 48 hours. The center of the storm is expected to approach the region near the border between Nicaragua and Honduras by late Friday.
"Preparations to protect life and property should be rushed to completion," the hurricane center said.
A hurricane warning is in effect for the area from Puerto Cabezas to Limon, Honduras, including nearby islands. And a tropical storm warning is in effect from Limon westward to the Guatemala border.
A storm surge is expected to produce coastal flooding where the center makes landfall, the weather center said. The weather system could dump 6 to 10 inches of rain over portions of Nicaragua and Honduras, with up to 15 inches falling in isolated areas, forecasters said.
Meanwhile, Tropical Storm Lisa was expected to turn northwest and increase speed.
As of 5 a.m. ET, the center of Lisa was about 295 miles (475 km) northwest of the Cape Verde Islands. The storm's maximum sustained winds were at 40 mph (65 kph).
There were no watches or warnings in effect, but the northwestern Cape Verde Islands could see locally heavy rainfall associated with Lisa, the Hurricane Center said.