How Unusual Is Snow and Ice in the South? More Typical Than You Think

At a Glance

• Just about everyone north of the immediate Gulf Coast picks up some wintry precip each year.
• Freezing rain is a nuisance for many across the south, especially east of the Appalachians.
• Most cities in the South see at least one day of snow or ice each winter.

Most of you would associate the South with an escape from winter's snow and ice.

In Florida or South Texas, that is true virtually every year. For other parts of the South, snow and ice are much more common than you may think.

Several times each winter, the polar jet stream dislodges arctic air from Canada, Alaska, the North Pole or even Siberia and sends it plunging deep into the South. 

Typical Southern Wintry Setup

The typical jet streams, cold air and moisture configuration for South snow and/or ice in the winter.

At the same time, the southern branch of the jet stream, called the subtropical jet, rides over the southern tier of states, with numerous disturbances in its flow, providing lift in the atmosphere.

The lifting of that jet stream-level moisture, plus any moisture from the lower levels of the atmosphere originating over the Gulf of Mexico, will wring out precipitation. If cold air is in place, at least near the ground, the South can get snow, sleet or freezing rain.

At times, particularly in January or February, this weather pattern will lock in place, delivering several rounds of wintry precipitation in the span of several days to a week or more.

There are two other patterns that can produce significant snow in the South:

• Slow-moving upper-level low-pressure systems able to provide enough lift and moisture to produce heavy, wet snow in a relatively small area. 
• A powerful low-pressure system cranks up in the Southern Plains, Gulf Coast, or off the Southeast coast. These systems are much more rare. (Examples: February 1899 | Superstorm 1993)

Average annual snowfall - South

Average annual snowfall in the southern U.S., based on the 1981-2010 period.

(NOAA)

Southern Snowfall

As you can see in the map at right, for much of the South, at least measurable (0.1 inch) snow is typical each year, extending into south Georgia, southern Alabama, Mississippi, Louisiana and Texas. 

But these are averages taken over the most recent 30-year normals from 1981-2010. For a deeper dive, let's examine a few cities:

Charleston, South Carolina, has had a trace of snow the past five winter seasons, including January 2018's 5.3 inches of snow. That event was the heaviest snow there since an 7-inch pre-Christmas dumping in 1989. Dating to 1938-39, Charleston picked up at least a trace of snow 63 of those seasons and measurable snowfall (at least 0.1 inch) 21 of those seasons. 

At the southern end of the Appalachians, Atlanta (Hartsfield-Jackson International Airport site) has picked up at least a trace of snow each season since the 1998-99 season.

Dallas-Fort Worth had seen measurable snow the last 11 seasons from 2006-07 through 2016-17. This includes a record-breaking 12.5-inch snowstorm Feb. 11-12, 2010 and a rare White Christmas in 2009 (2 inches on the ground) and falling snow on Christmas 2012 (0.4 inch). DFW only picked up a trace of snow in the 2017-2018 season. 

Here are some statistics on the average number of days with measurable (at least 0.1 inch) snowfall each year.

• 1 day at least every other year in the southern extent of the map at right
• 2 days in Dallas, Atlanta and Charlotte
• 4 days in Norfolk, Virginia; Knoxville, Tennessee and Ft. Smith, Arkansas
• 6 days in Nashville and Oklahoma City
• 11 days in Amarillo, Texas

(MORE: What You Should Know About Snow Maps)

Yearly Freezing Rain Days

Average number of days with freezing rain reported in the South, based on data from 1948-2000.

(Adapted from Changnon and Karl, 2003)

Ice: Another Typical Southern Threat

Perhaps just as common each winter is at least one, sometimes multiple, episodes of sleet and/or freezing rain in the South.

This occurs when air near the ground is below the freezing mark, but air a few or several thousand feet aloft warms above freezing. As a result, the unfrozen precipitation aloft either refreezes before reaching the ground (sleet) or freezes on contact with a cold surface (freezing rain).

(Winter Weather 101: What You Need To Know To Be Prepared For Snow, Ice and More)

The map at right shows the average number of days freezing rain is reported each year.

Notice how the 2 and 3+ days contours nose southward in the Piedmont of the Carolinas and North Georgia? This illustrates how cold air will bank up against the east slopes of the Appalachians, then get turned southwestward. Often during the winter, this cold air will linger as warmer, more moist air aloft rides over it. The result: sleet or freezing rain. 

So keep in mind that your winter escape to the South may not be an escape from snow and ice.