(CNN) -- Matthew weakened to a remnant low Sunday but continued to dump heavy rain over eastern Mexico and Central America, as forecasters project it to come to a virtual standstill later in the day.
As of 11 a.m. ET, Matthew was about 40 miles (65 kilometers) south of Villahermosa, Mexico, according to the National Hurricane Center in Miami, Florida.
The Mexican states of Chiapas, Tabasco, Oaxaca and Veracruz have already experienced heavy rain.
Matthew could dump between 10 and 20 inches of rain from southern Mexico into Central America, the weather agency said. Parts of Guatemala have already received more than 6 inches of rain.
"These rains could produce life-threatening flash floods and mudslides," the center said. "The threat for heavy rain will continue over portions of Central America even after the remnant of Matthew dissipates."
Matthew carried maximum sustained winds of about 25 mph (35 kph) Sunday morning, the center said. It was moving west at about 9 mph (15 kph), but is expected to slow down in forward movement. Matthew is forecast to weaken in the next day or two and could become nearly stationary by Sunday night, the center said.
Meanwhile, the cyclone known as Lisa has weakened from a tropical storm to a tropical depression in the Atlantic Ocean.
As of 10 a.m. ET, Lisa was about 740 miles (1,190 kilometers) north-northwest of the Cape Verde Islands, the hurricane center said. It was moving north-northwest at about 7 mph (11 kph) and carried maximum sustained winds of 35 mph (55 kph).
Tropical Depression Lisa is expected to become a remnant low later Sunday and is currently not forecast to threaten land.