Cold Spring

The weather has not been kind for us on the east coast these past few weeks. After a reasonably mild winter, late winter/early spring has been filled with snow, cold, and more snow. There may be a silver lining to this though. Here is my completely unsubstantiated account of North American weather patterns.

Anyone who watches the weather channel knows that when it is cold on the east it's because a cold front has moved in from Canada. I heard it being called an Alberta Clipper this morning. The atmosphere gets warmed or cooled primarily through contact with the ground since solar radiation mostly passes through the air and is absorbed by the ground. In the winter and spring, the air over north western Canada is cold while the air over the Gulf of Mexico and the southern US is mostly warm. Thus a pressure gradient can arise with high pressure in Canada and low pressure in the southern US. This causes air to flow from north to south.

Now all that air coming down must go somewhere so it makes it's way up the Atlantic coast and returns to the arctic. Along the way, it picks up warmth and moisture which often ends up as snow in New England. Hence, the more cold air there is coming from the north, the more warm air there will be returning to the arctic. This should then lessen the temperature and pressure gradient between the north and the south. So, perhaps a cold late winter may actually lead to a milder late spring.