Tuesday, February 9, 2010

Nor'easters: Winters Most Ferocious Storms!

Time for a Meteorology Lesson

Everyone has been asking why there has been so much snow! What is causing this crazy, abnormal winter pattern? No matter what the cause is, which is likely ‘attributable’ to El NiƱo, atmospheric conditions this winter have been absolutely perfect for Nor'easters to form.

But what is a Nor'easter? The term has been thrown around in the news more times this winter than in the past decade, but what is it? For those inquiring minds, here's some insight.

A Nor'easter is a large-scale cyclonic storm with extremely deep low pressure that forms along the east coast of the United States. Conditions need to come together perfectly for a Nor’easter to form, and that is usually when the very cold Labrador current meets the warm Gulf Stream current (see image 1). Typically this will take place between 50 and 250 miles off the southeast United States. At the same this is occurring there needs to be a steady flow of arctic air from the north. The friction that occurs from the cold air to the north moving across the North American continent, and the warm air being pulled up from the Atlantic, causes the developing low pressure to begin to spin and move northeastward along the jet stream (see image 2). As it does so a Nor’easter is born and its tight rotating center of circulation will cause fierce winds from the northeast to affect any land in its path. Coastal areas are often battered by high seas and coastal erosion, and just inland you’ll find crippling snowfall amounts, deadly wind chills, damaging winds and torrential rains.

In addition to the impending blizzard tonight into tomorrow, recent memorable Nor'easters are the DelMarVa Blizzard of February 2010, the December 19 Blizzard of 2009, the Blizzard of 2006 (absolutely epic for NYC, three feet of snow in three hours / total snowfall near 30 inches in less than 24 hours), the Blizzard of 2003 (also known as the President's Day Storm II), and let's not forget a very, special Nor'easter that occurred in the off-season this past Autumn: Nor'Ida! Nor'Ida developed from the remnants of Hurricane Ida which after crossing the Gulf Coast, rode up the Atlantic seaboard, causing extremely heavy rain, coastal destruction and damaging winds! In New Jersey alone Nor'Ida caused coastal flood damage that left $168 million in losses.