The most intense arctic blast to strike New England in recent memory has now become a memory as temperatures are set to shoot into the 40s and 50s for most of this week. For a 36 hour period, a "once in a generation" blast of arctic air gripped the northeast. Naturally, this caused some rather interesting phenomena to occur across the region.
1. A ground blizzard
A blizzard warning for a ground blizzard is not something I thought I would ever see happen in New England, but it occurred in northern Maine. The official definition of a blizzard is winds of at least 35mph causing blowing or drifting snow that drops visibility to a quarter of a mile or less for at least three consecutive hours. A ground blizzard occurs when snow is picked up off the ground and all of the above criteria are met while no snow falls from the sky.
This typically happens in the Midwest due to flat, wide open plains with plenty of room for snow to blow around and little by way of trees blocking the wind. New England, on the other hand, has varied terrain and is heavily forested, making ground blizzards a difficult thing to happen. Well, in this arctic blast, it happened. The front brought very strong winds to northern Maine, where there are flat, open agricultural fields. This allowed recently fallen snow to blow around so much, a portion of route 1 had to be shut down.
2. "Exploding trees"
At one point Friday night, reports of "exploding trees" were coming in from New Hampshire and Maine. This occurs when the tree's sap freezes inside of the tree. Normally, tree sap works as a natural antifreeze for the tree, however, when temperatures fall to extreme levels trees in an area are not used to, the sap can freeze. When this happens, the frozen sap expands and causes the tree to shatter. When the tree shatters, it creates a sudden, loud bang, like a gunshot. The trees do not dramatically explode like they were struck by lightning, but the bang is loud enough to disrupt sleep across the region.
3. Frost quakes
Frost quakes occur when temperatures fall rapidly and freezes groundwater. The newly formed and expanding ice pits pressure on the frozen soil and bedrock. The pressure continues to build and build until the soil and bedrock cracks and breaks. This cracking can cause loud booms and even some shaking, like a small earthquake. The key to frost quakes is a recently saturated ground. New England has had a mild, wet winter thus far which has resulted in a very soggy ground. This arctic blast was not the first time this winter this weather phenomena has happened here in New England.
4. Sea smoke
Sea smoke occurs when a very cold air mass sits over relatively warm, open water. Despite its name, this phenomena does not only occur in the sea, it can occur in any body of water that is open. Sea smoke was seen over the ocean up and down New England's Atlantic coast, as well as on Lake Winnipesaukee and Lake Champlain. This, like the frost quakes, occurred in New England due to the mild winter, which has resulted in warmer than average ocean and lake water.
5. Steam devil
Piggybacking off of number four, one of the more interesting phenomena that occurred during this two day blast was the formation of steam devils on Lake Champlain. Steam devils are small, weak whirlwind over open water that draws in fog or steam, making it appear as if a waterspout has formed. In this case, the whirlwind drew in the sea smoke from the lake.
6. White Mountains in the stratosphere
In a grand showing of just how powerful this event was, the arctic blast actually forced some of New Hampshire's higher summits into the stratosphere. When this air mass moved in, the cold, very dense air sinks and "pushes" the troposphere down to lower levels. Typically, the bottom of the stratosphere is between 30,000 and 50,000 feet. Early Saturday morning, the border between the troposphere and stratosphere was around 5,000 feet for a time. The event is called a 'tropopause fold'.
7. Record setting wind chill
While Mt. Washington was not able to set an all time low for air temperature for the state (which is -50F), the extreme winds were able to set a new record for wind chill in the United States. For a little while, the wind chill dropped to a staggering -108F early Saturday morning. The air temperature was in the -40s with winds gusting as high as 120mph. While there's no official record kept of wind chills, the previous all time low wind chill documented in the United States is -105F, which occurred in Alaska. Mt. Washington's previous wind chill record was -103F, which occurred in 2004. All of Mt. Washington's numbers from this even still need to be verified.
