Without moisture in the air, there can be no precipitation, rain or snow. Robinson says there is evidence of snowstorms becoming stronger because of the relationship between moisture and precipitation.
“The warmer the air becomes, the more moisture it holds. So, if it’s warming and still cold enough to snow, you can get more snow,” Robinson says.
Of the 10 biggest snowfalls recorded in Washington, five have occurred in the past 25 years, according to the National Weather Service. During that period, average winter temperatures have been steadily rising. The National Weather Service’s “unofficial” D.C. climate data shows that in 1996, the average winter temperature was 35.3 degrees. In 2020, it was 42.8 degrees.
This data seems to support Robinson’s explanation that warmer temperatures may lead to more powerful storms.
Still, it is hard to make conclusive statements about the relationship between higher temperatures and snow because of how infrequently snowstorms occur.
“These big snowstorms are pretty rare, so it’s difficult to really determine if we’re seeing any change in how often they occur and how strong they are,” Robinson says.
What scientists need is more data, and some of it could come from you.
Robinson and his team use volunteer-collected weather observations to make maps and tables about weather patterns.
“We have a volunteer-observing program that is part of the [Community Collaborative Rain, Hail and Snow Network],” Robinson says. “We’ve even got kids in elementary school who, with their parents, make daily precipitation observations and go online and enter them as part of a national database.”
The network began in Colorado in 1998 and now is in every state. Robinson began making his own weather observations as a fourth-grader. You can find out more about the program at the website, cocorahs.org.
For now, while weather observations suggest that rising temperatures may make winter shorter and less cold, the snow is still falling.
“In the Washington area, near-record, if not record-breaking [snowstorms] are still part of the weather scene,” Robinson says.
Until temperatures of entire winters stop dropping below freezing — 32 degrees — we will continue to see powerful storms. Once temperatures are consistently above freezing, potential snowstorms become rain.
According to Robinson, that time could come sooner than we think. He says, “When we look back, years from now, we may see that this was the breaking point.”
Top D.C.-area snowstorms
Within three days; 1884-present
|1. January 27-29, 1922||28.0|
|2. February 12-14, 1899||20.0|
|3. February 18-19, 1979||18.7|
|4. January 22-23, 2016||17.8|
|5. February 5-6, 2010||17.8|
|6. January 7-9, 1996||17.3|
|7. February 10-11, 1983||16.6|
|8. December 18-19, 2009||16.4|
|9. February 16-18, 2003||16.4|
|10. February 7, 1936, and February 15-16, 1958||14.4|
Source: National Weather Service