In the east of the USA and Canada, polar air currents with strong gusts of wind have caused extreme frost. According to the US weather agency NWS, the wind chill temperature at the summit of Mount Washington in New Hampshire fell to minus 78 degrees Celsius on Saturday night – the lowest value ever measured in the United States. So-called frost tremors, earthquakes caused by extreme cold, have also been observed in the region.
According to the US broadcaster CNN, the new wind chill record measured on Mount Washington was below the previous low of minus 76 degrees Celsius, which had been measured in Alaska. It was caused by the combination of an air temperature of minus 43 degrees and gusts of wind with a speed of up to 177 kilometers per hour. At 1,920 meters, Mount Washington is the highest peak in the Northeastern United States, and the mountain is notorious for its extreme weather conditions.
The NWS field office in Caribou, further north in the state of Maine, reported a wind chill temperature of minus 51 degrees for the town of Frenchville, which is on the border with Canada. According to the NWS, such temperatures can lead to frostbite on unprotected skin within five minutes.
In addition, so-called frost quakes were reported from the region. According to the NWS, these tremors on the earth’s surface are caused by sudden cracks in frozen ground or frozen water in the bedrock.
Before the cold snap, the US weather agency had warned of arctic cold that “only occurs once in a generation”. The state of Maine has not experienced a similar frost since the 1980s.
However, temperatures were also as much as 15 degrees below seasonal averages across much of the U.S. Northwest and the Atlantic Seaboard, according to the NWS. There were weather warnings due to the extremely low temperatures, as well as in the Canadian province of Québec and other parts of eastern Canada. A wind chill temperature of minus 41 degrees was measured at the airport in Montréal, and minus 34 degrees in Boston. In New York City, minus 16 degrees were measured in Central Park.
During the course of Sunday, warmer air masses should put an end to the extreme cold.