Winters are getting warmer pretty much everywhere, but at the same time, seven of the ten heaviest snowstorms in New York City’s weather history (which dates to 1869) have now come within the last 20 years. A similar trend holds for DC and Baltimore. Something is clearly different recently.
There are a lot of reasons for this, including a big boost from a very strong El Niño(and some other factors that are, frankly, probably either random chance or not well understood), but there is clear evidence global warming is boosting the odds of recent big Northeast snowstorms. Among the clearest is Physics 101: A warmer atmosphere is able to hold more moisture, and thus can produce heavier precipitation (whether rain or snow) in a shorter amount of time. At the moment, exceptionally warm waters off the East Coast (as high as 76 degrees Fahrenheit!) are boosting the amount of water vapor in the air by about 10 to 15 percent, according to Kevin Trenberth of the National Center for Atmospheric Research.
Looking ahead to the forecast for the next few days, warmer than normal temperatures are expected to resume for the foreseeable future, meaning this snow—as heavy as it was—won’t stay around for long. And that, of course, is partly due to global warming too.