If you were to look outside at Rowan’s campus on Wednesday, there’s probably no real indication that spring officially started this past week.

Glassboro has seen its fourth Nor’easter in less than three weeks and is leaving many wondering, what gives? When will spring get here? When will the snow end?

I don’t have a crystal ball, but considering that we are about to turn the calendar from March to April, with the sun angle getting higher each day as we now countdown to summer, I don’t see anymore chances to see crippling snow like we’ve seen recently.

As far as the round after round of Nor’easters, there is a specific, atmospheric phenomenon as to how these storms are being engineered.

To pull off these classic storms, a few ingredients need to be put in place. First, when the upper-level jet stream, a strong flow of wind up in the air that pushes the weather around the world, dips far to the south, cold air from Canada sinks into our area.

Next, warm, moist air from the Gulf of Mexico latches onto the lower jet stream and is brought north. When these forces meet, the counter-clockwise winds around the low pressure system is amplified and a storm is born.

Obviously, the track of these storms is always important. If the low pressure tracks too close inland, the warm air from the ocean comes ashore and we see rain. Too far out and we see flurries or nothing at all. The perfect middle between the two leads to us getting a good snowstorm.

So that explains how Nor’easters are formed, but how have we gotten so many in such a short amount of time?

There is another phenomenon called the North Atlantic Oscillation (NAO), which is the atmospheric pressure at sea level between the Icelandic low and the Azores high.

The NAO has two phases, positive and negative. When the NAO is negative, as it is now, the upper-level atmosphere tends to be colder than usual in our region.

The NAO has been negative for the past few weeks, allowing for the combination of the cold air in place along with the moist air from the Gulf, to be fed into the jet stream up the East coast. This is what has led to the constant barrage of cold, snowy weather.

As mentioned, I don’t have a crystal ball and I can’t tell you if Commencement in May will be wet or dry, but hopefully this explanation of the science behind our recent stretch of wintry weather will help you understand how complex but beautiful mother nature is!

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