South shivers, but is this week's snowstorm a harbinger of spring?

The early chirpings of spring birds were quieted Thursday as what could be a brutal winter’s last big snowstorm chugged through much of the US South and up into the now-fabled snow metropolises of the US Northeast, leaving motorists stranded and National Guard troops scrambling.

But for all its intensity – almost 50 million people were affected, and four governors declared states of emergency – the storm may be more a harbinger of spring than a reminder of winter. Indeed, the threat of spring flooding increased in Kentucky as emergency managers nervously eyed the Cumberland River. 

On its own, the early March storm and accompanying cold might have been unusual any other year. Given record amounts of snow in Kentucky, the papers in Lexington labeled this latest storm “legendary.” 

But considering what preceded it, winter storm Thor, as The Weather Channel dubbed it, was more an average Joe for the United States this year. Boston has seen one of its biggest snow years ever, and much of the East, South, and Midwest has been huddling as far-below-average temperatures pressed against walls. In February, especially, temperatures across the East were “quite a bit below average,” in the words of National Weather Service meteorologist Ryan Willis in Peachtree City, Ga.

At its height this week, the storm system stretched from Arkansas to New York City. In its wake, the barometer rose but temperatures sank, going from 74 to 48 degrees in Greenville, Miss., in an hour’s span.

Parts of Kentucky were arguably hit worst, as hundreds of motorists had to turn survivalists as they spent the night on Interstates 24 and 65 in the western reaches of the Bluegrass State. At one point, standstill traffic stretched for 55 miles, though lanes were moving normally as of Friday morning. National Guard troops walked car to car as victims eyed their gas gauges and snuggled up the best they could. Some had to be taken to warming shelters as the situation proved too intense.

Flooding has already affected 50 Kentucky counties, including where the Levisa Fork of the Big Sandy River inundated low stretches at Mossy Bottom.

As a dusting of snow quickly melted Friday morning in Atlanta, there were signs that winter is about to let go. Thursday’s full moon marked the early stirrings of the spring white bass spawning run up the South’s muddy tributaries. The flycatchers are back in northern Georgia, fully expecting the first maggots of spring. Also, the redheaded woodpeckers have begun to pair up.

The equinox is only two weeks away, and evening gets an hour longer on Sunday thanks to daylight saving time.

In Georgia specifically, but also more broadly across the eastern half of the US, there will be a “general warming trend ... getting into a more typical March temperature pattern for the next week or so,” Mr. Willis says. 

The weatherman, however, demurred when asked if he was ready to announce that this means spring really is just around the corner.