HOUSTON — Heavy rains that caused flooding in some parts of the Houston area and prompted about two-dozen water rescues on Tuesday seemed to have stopped just before getting worse but with more rain expected authorities remain on guard and residents should stay prepared, officials said. “Unfortunately, this is one of those Texas flood events that’s part of living in Southeast Texas,” said Michael Walter, a spokesman for Houston’s Office of Emergency Management. While the thunderstorms that dropped up to 5 to 6 inches of rain in some parts of Houston overnight Tuesday have mostly moved out of the area, additional storms could pop up Tuesday afternoon, which could cause additional flooding in areas already saturated by rainfall. “We don’t want anyone to let their guard down just because it stopped raining for now,” Walter said. Authorities plan to pre-stage emergency vehicles and barricades in different areas of Houston just in case expected rainfall Tuesday afternoon and evening becomes problematic, Walter said. The National Weather Service has issued a flash-flood watch for the region until Wednesday morning. Jeff Lindner, a meteorologist with the Harris County Flood Control District, said he expects some homes and structures will be flooded but that tally is still being determined.