If someone states to you that New England does not receive wild and crazy weather, you can certainly prove him wrong through the incredible conditions that the Mount Washington Valley received this week. It seems as if every spring season produces a period of radical differences in temperature and precipitation during a short period of time. Let us review the third week of April from last year as an example. During that particular week, North Conway recorded a maximum temperature of 91 degrees on the 17th, was shoved by a 5.1 earthquake on the 20th, and received two inches of fresh snowfall on the 22nd. Not bad for a seven day stretch of weather!
So, let's take a look at this past week. What made it so radical? First of all, North Conway did not receive an earthquake, nor did it receive a major accumulation of snowfall. However, the region experienced a remarkable contrast in temperatures that only occurs on a rare basis. Before Tuesday, April 15th, the Mount Washington Valley had received a few days of above normal temperatures. However, this pattern quickly changed as the very same day witnessed a seesaw temperature contrast like none other. A frosty 29 degrees was recorded at 7 AM on Tuesday, but in eight hours time, the temperature rose 54 degrees to peak at a summer-like maximum of 83 degrees.
The heat on Tuesday was short-lived due to a cold front, which had been nearly stationary across southern Quebec. It began to push its way through New England on Wednesday. Unlike many cold fronts that North Conway has received, this one decided to pack a firm punch. When it rolled through the region, an automatic wind shift towards the northwest took place with strong and gusty winds. With these winds came a significant drop in the temperature until the weather in North Conway stabilized itself. At one point during the afternoon of Wednesday, a 50-degree range in temperature simultaneously occurred across the state of New Hampshire. The Great North Woods experienced winter, the White Mountains received a glimpse of autumn, the Lakes Region witnessed spring, and the Merrimack Valley warmed with summer heat.
If you enjoyed the glimpse of warmth this past week, you can thank a dominant southwesterly airflow that opened the gates for such weather. However, if you marveled at the sharp contrast in temperatures and the fast transition back to reality, you can express gratitude towards one of nature's most unappreciated phenomenon, which is known as the backdoor cold front. In the United States, most cold fronts move in the atmosphere from west to east. However, the back door cold front breaks all rules as it invades from the northeast and slides its way southward through the eastern United States. This frontal system often forms when a high pressure is centered in and around the Canadian Maritimes. The high pressure helps to destabilize warm, inland air with cool, oceanic air. The result is an experience like that of this recent week in New England. Will it occur again? Knowing the crazy weather that North Conway receives, the answer is that anything is possible.