LOS ANGELES - Tropical Storm Isaias is regaining strength and is expected to become a hurricane by Monday night as it bears down on the East Coast.Isaias is expected to push ashore into the Carolinas later Monday, bringing heavy rainfall, damaging winds and life-threatening storm surge to the East Coast.The tropical storm formed from a large tropical wave, which developed off the West Coast of Africa in late July.As of Monday morning, Isaias had wind speeds of 70 mph — only four less than hurricane status.Joel Cline, tropical program coordinator with the National Weather Service, said the center of the storm system was never aligned. “For it (Isaias) to be as well-tracked and as well-forecasted as it was and has been to this point is really.