HOUSTON: Heavy rains fuelled by the meeting of  two storm systems, one the remnants of Hurricane Patricia, pounded  southeastern Texas, triggering flash floods and derailing a freight  train as heavy weather descended upon Houston early on Sunday. The  National Weather Service predicted 15 to 30 cm rain for coastal areas,  including southwest Louisiana, by Monday morning, exacerbated by tides  up to five feet and wind gusts up to 60 kph. The rain systems were  intensified by Patricia, which was downgraded to a tropical depression. As the  storms moved eastward early on Sunday, cities in the state’s flood-prone  Gulf of Mexico region braced for the impact. They include Houston, the  state’s second-most populous metropolitan area with 6.1 million people.  Mayor Annise Parker warned residents to stay away from wet roads after  dark and be aware of flash floods, which the National Weather Service  said were occurring in the city early on Sunday