2011 Groundhog Day Blizzard, North America

An ice storm ahead of the winter storm's warm front also brought hazardous conditions to much of the American Midwest and New England, as many areas were expected to receive well over 1 in (2.5 cm) of ice accumulation. Numerous power outages, flight cancellations, airport closures and pre-emptive bus and school cancellations took place ahead of the main storm. Several tornado touchdowns were reported in Texas and a tornado watch was issued for parts of Alabama, ahead of the cold front in the warm sector of the storm. In addition, thundersnow was recorded at some locations, increasing the overall snowfall rate.
Meteorological synopsis
By the end of January, an Alberta Clipper containing cold air from the polar vortex drifted across The Dakotas, while a large Arctic high pressure system with a maximum pressure higher than 1,050 millibars (31 inHg) followed behind it, moving across Montana. A low pressure system from the Pacific Ocean later crossed the Rocky Mountains, merging with the Alberta Clipper low and a developing Texas low drawing moisture from the northwestern Gulf of Mexico. The storm later intensified, developing a long warm front stretching toward the New England states, and moving northeast along this jet stream track.