Such events distort the polar vortex, which causes Arctic air to descend into the U.S. and causes temperatures to plummet.

No rest for the winter weary after the first significant snow of the season fell in Massachusetts on Tuesday. The weather forecast shows an early-season Arctic blast is on the way to the Boston area. A cold front will pass through New England Thursday afternoon, ushering in the coldest air since last winter.

The brutal cold will continue with temperatures Monday night as much as 20 degrees below normal, forecasters say.

A cold weather advisory was issued by the NWS San Francisco CA on Wednesday at 5:46 p.m. valid for Thursday between midnight and 8 a.m. for Southern Salinas Valley/Arroyo Seco and Lake San Antonio and Monterey County.

An updated winter weather advisory was released by the NWS Blacksburg VA on Friday at 6:40 p.m. in effect until Saturday at 8 a.m. The advisory is for Stokes, Rockingham and Caswell counties.

We've issued a First Alert Weather Day for Friday morning because the wind chill is downright dangerous. Early Friday, it will feel like the teens and even single digits thanks to biting wind chills. So, layers are your best friend.

At 1:22 a.m. on Friday, the NWS San Francisco CA released a cold weather advisory in effect until 8 a.m. for North Bay Interior Valleys and East Bay Interior Valleys.

Below-freezing temperatures are forecast for Denver until about 11 a.m. Thursday, according to the NNWS. Until then, ice will remain on roads throughout the Denver area.

The two periods of light snow also will affect two different areas. The first snow shower burst will roll across northern Lower Michigan and the Upper Peninsula Friday night into Saturday morning. This snow should just be a very spotty light snow as it moves into southern Michigan. I would say it runs out of gas heading south.