Back Door Cold Front A cold front moving south or southwest along the Atlantic seaboard and Great Lakes.
Backflow The backing up of water through a conduit or channel in the direction opposite to normal flow.
Back Door Cold Front- A front that moves east to west in direction rather than the normal west to east movement. For instance, one that enters Southern New England from the Gulf of Maine.
See also: What is the meaning of Sustained wind, Cloud, Cold front, Density, Energy?