Most of the US will enjoy milder temperatures on Thursday, but the warmup will be brief as a polar vortex will send temperatures tumbling below freezing for most of the nation starting this weekend.

With the Northern Hemisphere well into the winter months, it may seem like temperatures are cold enough already. However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is ...

Worst of the polar blasts may not be over Back-to-back fronts sent temperatures plunging READ MORE: Yet another icy winter blast strikes on Thursday Two more icy cold fronts are expected to sweep ...