Enjoying a day at the Jersey Shore in the early summer can go either way. One visit you may be shivering underneath the towel while a few days later you're sweltering, running for the ocean. But what causes these difference? Most likely, it is a simple matter of wind direction. Knowing where the wind is coming from gives important insight into what kind of temperatures we can expect. In fact, wind direction is one of the first things a meteorologist looks at when forecasting the weather. For us in the Northeast, our temperatures change the most if wind blows off the Atlantic, down from Canada or up from the Gulf of Mexico. Let's investigate each of these directions and its affect on temperatures in the Northeast.
While shorter daylight hours in the winter help lead to colder temperatures, northerly winds only enhance the frigid feel. According to the Rutgers University Global Snow Lab, more than 50% of the ground is snow covered in eastern Canada from late-November to mid-April on average. As a result, winds blowing over the deep Canadian snow pack become even colder and often keep these chilly characteristics traveling even further south into our neck of the woods.
Let's head back to the beach and, more importantly, the Atlantic Ocean. Just like land, the ocean heats up during the summer and cools down in the winter. However, it does so at a slower pace. As a result, the ocean often stays cool into June and warm into October. Therefore, easterly winds, mainly during the transition months, usually bring in temperatures similar to that over the ocean which can be much different than inland. This leads to chilly spring or early summer temperatures with highs only in the 50s or mild autumn temperatures in the 70s.
One thing the Northeast is known for is its weather diverstiy. During some sultry summer days, it's not unheard of for places from Baltimore to Boston to roast into the 90s with high humidity, making it feel more like the South! How does this happen? Typically, it's due to strong southwesterly winds that circulate around the semi - permanent Bermuda high off the Southeast coast. With the Gulf waters well into the 80s from May until October, southwest winds pump this hot, humid air into the Northeast and can keep things feeling "tropical" for consecutive days. Of course, these types of air masses provides us with key ingredients needed for severe weather which can fire off as cold fronts alleviate us from the heat.
So the next time you are out and about, ask yourself why the temperatures have changed so drastically from one day to the next. Then, take a look at where the wind is coming from. You'll be suprised to learn just much insight it can give you.