BROWNSVILLE, Texas — Widespread flooding was expected Thursday from Hurricane Dolly that has loitered as a tropical storm overnight, soaking deep south Texas and northeastern Mexico with more than foot of rain. Dolly slammed ashore Wednesday, ripping roofs off buildings with 100 mph winds. Those winds had dropped by half as of 7 a.m., and forecasters say the tropical storm warning for the Texas coast would likely be canceled later in the morning.