December 25 Research from 40 years of the United States shows that less parts of the country now have snow for Christmas than in the 1980s. And the snow that falls does not measure up to the previous depth.
Federal weather records show that mean December temperatures in the continental US were slightly below freezing from 1981 to 1990. From 2011 to 2020, it averaged less than 2 °C.
Research by the University of Arizona for the Associated Press shows that from 1981 to 1990, about 47 percent of the country had snow on average on Christmas Day. This showed that the average depth was 8.8 cm. From 2011 to 2020, Christmas snow cover was down by 38 percent with an average depth of 6.8 centimeters.
The change is very apparent for the region running from Baltimore, Maryland to Denver, Colorado and a few hundred miles north to Detroit and Chicago. Information from Arizona shows that Christmas snow cover has increased from an average of about 55 percent in the 1980s to just above 41 percent now. Average snow depth fell from 8.8 cm to 6 cm.
Zubin Zeng is an atmospheric scientist at the University of Arizona who ran the information. Zeng said the numbers are so small it’s hard to tell if it’s meaningful. trend And, if so, if it is due to climate change or natural weather differences.
Still, Zeng said the snow has decreased with climate change along the lines of Christmas.
Climate scientist Imke Durre said places with at least a ten percent chance of snowfall on Christmas moved north with the new normal. The nation’s capital, Washington DC, increased from ten percent to seven percent.
“The speed of that line is similar With a hot December,” Durre said. New York, Philadelphia and Concord, New Hampshire saw a slight increase in the likelihood of a Christmas snowfall.
David Robinson is a climate scientist at Rutgers University in New Jersey. He said the university has information based on satellite imagery from 1966. It shows that there has been a slight increase in continental US snowfall, not death, in the last week of December.
“There’s no trend. You don’t see it,” Robinson said.
That said, people in the ’60s and ’70s often think there are fewer Christmases with snow, because the 1960s had more than a normal Christmas with snow.
Meteorologists, or scientists who study the weather, said that temperature changes snowfall in two different ways. In warm border areas, warm air turns snow into rain. But in the colder more northern regions, where high temperatures are still below freezing, warmer temperatures mean more snow. This is because the warmer air contains more water which comes down as ice.
Many meteorologists warn about finding trends in large amounts of information where both temperature and rain or snow are affected.
Victor Jancini is a meteorologist Professor at Northern Illinois University. Even with those issues, he said, less Christmas with snow appears to be linked to warmer temperatures from climate change.
I am Gregory Stachel.
Seth Borenstein reported this story for The Associated Press. Gregory Stachel adapted it for VOA Learning English. Susan Shand was the editor.
words in this story
trend – N. A general direction of change: a way of behaving that is moving forward and becoming more common
similar , Adjective agree to something
Professor , N. a teacher of the highest rank, especially in a college or university