February was extremely warm — the warmest such month on record by a landslide. Global temperature was 2.43 degrees higher than average, according to NASA, which was the largest temperature departure on record for any month in any year since 1880.
That warmth translated into exceptionally low snow cover across the Northern Hemisphere last month, according to data from the Global Snow Lab at Rutgers University. Snow extent across the Northern Hemisphere was 43.51 million square kilometers — the lowest February extent in 14 years.
Only two Februarys were lower: 2002 and 1995. The Global Snow Lab data goes back to 1966.
Perhaps nowhere in North America was this more blatantly apparent than in Alaska, which experienced one of its warmest and least-snowy winters on record. The iconic Iditarod race needed to import snow and shorten its ceremonial start in Anchorage. To make up for the lack of powder, Alaska Railroad volunteered to transport seven cars full of snow to complete a three-mile parade route.
The Global Snow Lab analysis is based on satellite data but it is not purely automated, says David Robinson, professor of geography at Rutgers. “A trained expert scrutinizes a multitude of sources, primarily visible satellite data but they also look at surface observations and even Web cameras in some places,” he said.
Robinson maintains the Global Snow Lab data, which he contends is the longest, most consistent environmental satellite product available, going back 50 years. And he says he’s seen a clear trend in recent decades: a noticeably early demise in springtime snow.
“There haven’t been big changes in the middle of winter — even if it’s warming up, it’s still cold enough to sustain snow cover in winter,” Robinson said. “But come the spring, we’ve noticed this in the 80s and 90s — it kind of stepped down to a new normal, if you will. And then May snow extent has really plummeted in the last decade.”
If you think this portends an exceptionally low snow extent in March, you’d be right. Looking through the first two weeks of the month, Robinson noted that the extent of snow across North America and Eurasia is receding much faster than normal — about 10 days to two weeks ahead of schedule.
“The only low-elevation areas east of the Rockies, or anywhere for that matter, are northern Maine, parts of the Upper Peninsula of Michigan and northeast Minnesota,” he said. “There’s no low-elevation snow anywhere else in the Lower 48 right now.”
Robinson pointed out that temperature doesn’t always correlate to below average snow cover. “It’s anomalously warm over and west of Hudson Bay right now. Well, there’s snow cover because it’s still cold enough to maintain snow cover.”
But the warmest months do tend to see decreased snowfall. So what prevented February 2016 from seeing the lowest extent on record? Remnants of the January blizzard, and a Midwest winter storm toward the end of the month.