Some residents in the Houston area along the east bank of the San Jacinto River were urged to leave before nightfall. Crews had rescued people and animals from flooded areas.
A series of powerful weather systems will move across the country, bringing heavy snow to the Plains and up to four inches of rain to the Northeast, forecasters said.
New York City warned residents to prepare for floods and major travel disruptions from a major storm that is expected to start Sunday evening and last into Monday.
More people are expected to travel during the holiday weekend as airfare and gas prices drop. But rain and cold could pose obstacles through early Wednesday.