This weekend brought brutally cold temperatures to much of the Northeast, causing school closings and grounding flights up and down the coast. The blast of frigid air is expected to linger well into the week, when a warm front will finally move in from the south. Forecasters warn that the sub-freezing temperatures combined with precipitation could make roads slippery and have dangerous and deadly consequences throughout the region. Residents are cautioned to dress warmly and not to engage in any unnecessary car travel.