WASHINGTON – Cold and snow keep battering the Midwest and East, and even Atlanta was temporarily paralyzed. California has been bone dry. Alaska set heat records. The wild winter somehow became even more wicked Thursday morning when the national average temperature plunged to a brutal 11 degrees, prompting a weather-weary nation to ask a simple question: Why? The answer is the jet stream, the river of air that dictates our weather. (MORE: Cities Sick of Snow This Winter) "A persistent...

Radar loop with lightning data (small white/gray lightning symbols) of Winter Storm Seneca from 9 a.m. CT Feb. 20 through 12 a.m. CT Feb. 21, 2014. Winter Storm Senecawas the second named storm of the week to produce snow accompanied by lightning and followed closely on the heels of Winter Storm Rex. (MORE: Seneca State-by-State Impacts) Seneca kicked into gear on the morning of Feb. 20, as a relatively quick burst of snow sweeping through parts of Nebraska and northern...

Winter Storm Rex brought a swath of snow from the Midwest to parts of the Northeast late Feb. 16 into early Feb. 19, 2014. Thundersnowwas observed in at least seven states as the storm pushed east. Here are some of the snow totals produced by the storm in each state. Official National Weather Service observations arelisted in bold. Maine All reports are snow accumulations. 9.6" near Kennebunk9.5" in Rollinsford9" in Durham7.6" in Portland New Hampshire All reports are snow accumulations....