“WEATHER 101” WITH AL KAPRIELIAN ~ Winter Weather

By: Al Kaprielian – Jan, 2017

Winter weather has arrived to our region. January is known as the coldest month of the year. With the start of January we are starting to see a ridge of high pressure build in Alaska. This causes the cold air on the east side of this high to build across Canada.

The clockwise circulation around this high causes the north/northwest wind to bring this very cold air southward into the US including New England. This will result in occasional intrusions of Arctic air into our region as we move through January. Occasionally there will be brief periods where the temperatures moderate into the 40s. However, no extensive or prolonged warm up looks likely at this time. So for this season the low pressure systems that have affected our area have been progressive (move along at a fast pace).

The reason for this is the lack of a high pressure system in Greenland and the North Atlantic Ocean. When this occurs there is no block in the atmosphere to cause the low pressure systems to slow down and give us a longer duration storm. An example of this was the low pressure system that occurred during the day and evening of December 29, 2016. The storm was moving pretty quickly so we saw the snow start to end by midnight and well before daybreak the next day. Due to this storm moving quickly it did not rapidly intensify until it got to the Central Maine coast. This was fortunate in that the winds did not get as strong as predicted for our area. The snow that fell from this storm was of the wet and heavy nature (contained a lot of water).

This caused some power outages, most of which occurred in New Hampshire, where higher snowfall totals occurred from the storm. The wet and heavy snow adds more weight to trees, tree branches, and power lines causing them to snap and fall. There would have been many more power outages if the stronger winds that were forecasted occurred. The snowfall made road conditions slippery and treacherous during the storm.

With ocean temperatures running warmer than normal and cold air over land areas, this may cause more low pressure systems to develop hence there is the possibility of frequent ocean storms this winter. Whether these storms track close enough to the New England coast to give us a significant storm is difficult to say. If there is phasing of the northern and southern jet streams then we will see these storms impact our region with heavy precipitation.

Also if the Greenland and North Atlantic high pressure system develop, this will cause more blocking and trend the storms to move slower and closer to our region. When winter weather occurs, a reminder, if you have to drive, slow down and allow extra time to reach your destination!!!

Next month we will examine the weather pattern and talk about blizzards as February is known as blizzard month. An example is the Blizzard of 1978! During this month the days will continue to get longer and by the end of the month the sun will set at 4:57 PM. I will leave you on this positive note and have a great January! Also if you ski enjoy the ski season.