The week of February 10th through the 15th is a fairly important part of weather history,  during this week back in 1983 there was a major blizzard that hit Washington DC, and south central Pennsylvania. In 2007 there was also a major blizzard that brought more than twenty inches of snow to some areas in New England, but also caused a tornado outbreak in southern United States.

The 1983 storm occurred between the dates of February 10th through the 12th and brought snow fall amounts of nearly three feet in some places to the south of Pennsylvania including Washington DC.  On the night of the 10th of February, there was a strong area of low pressure of the Georgian coast.  As I said in an earlier blog, air around the low circulates counterclockwise, which brought moist air of the cold ground in the DC area which was the primary cause of the snow.

image from NOAA

Back in 2007 however, the blizzard know as the Valentines day blizzard, formed much differently due to the fact that it was a low pressure system that moved in from the western coast.  This in turn caused the snow to be centered around the New England region.  Coming from the west also caused this system to produce tornado storms in the south, due to the cold dry air meeting warm moist air from the Gulf of Mexico.

image from NOAA

So from a blizzard in 1983, a blizzard and severe weather in 2007, to the surprise snow storm on  Wednesday, with the best packing snow ever, this week in February in truly unique.