MOUNT PLEASANT, S.C. (WCBD) – Cold Rain, Freezing Rain, Sleet, and Snow. When a winter storm is in the conversation, these terms are always thrown out in the mix. And most of the time, especially in the Lowcountry, we only see heavy amounts of cold rain.
With the potential for a winter storm expected to impact parts of South Carolina, we can clarify the difference between the terms, and why the Lowcountry doesn’t look like it will get any snowfall at all.
Snow is something that the Carolinas are no stranger to however, it seems as if the Lowcountry gets left out of the fun whenever a winter storm impacts the region. The last time the Lowcountry saw snow was actually not too long ago, with the Great Winter Storm of 2018, which was the third-highest recorded snowfall here.
Even though snow and ice are in the forecast for our neighbors in the upstate, and perhaps midlands, it doesn’t look like the snow, ice, or sleet will reach down to the Lowcountry.
Sleet and Freezing Rain
With this winter storm headed to the Carolinas, the midlands have a chance to see sleet/freezing rain. But what is the difference between the two, and what ingredients do we need to see these events? Different parts of the atmosphere have different temperatures, and that accounts for the differences we see between sleet and freezing rain. Sleet occurs when snow falls through the atmosphere and as it passes through a thin layer of warm air it melts. After it melts a bit, it will re-enter a pocket of cold air right before it reaches the surface. From there it refreezes and bounces off the surface like an ice pellet that we call sleet.
Freezing rain follows a journey similar to sleet on its descent through the atmosphere. Beginning as snow in the upper atmosphere, freezing rain reaches a larger warm pocket, melts, and becomes rain. Instead of re-cooling before hitting the surface, the water droplet reaches the cold Earth’s surface and freezes immediately becoming ice.
Forecasting for the coming winter storm, in particular, requires a lengthy process, with many variables.
The United States is currently in a weather pattern called La Niña. A La Niña winter typically means we see warmer, wetter conditions in the Pacific Northwest and warmer, dryer conditions in the Southeast. We have also seen warmer temperature trends within the last couple of weeks, even with this threat of freezing rain and sleet, models are leaning more towards just cold rain this weekend.
Currently, there is an active jet stream plunging south with widespread colder air, meaning the Carolinas are likely going to be affected. Winter storm warnings, watches, and advisories have been issued by the National Weather Service for Midwestern and Southern states. It is likely that additional watches and warnings could be issued while the storm is in its path and becomes more in focus.
There are still some uncertainties in the forecast, including exactly where low-pressure tracks and where the below-freezing air near the ground will set up and for how long. This could lead to changes in the forecast in the days ahead, which is typical for most winter storms. It doesn’t look as if the Lowcountry will be able to join the snow-day fun that our neighbors in the upper part of the state will be having.
We could possibly even see a rumble of thunder or two. Many details are still in the works as we wait for the Higher Resolution Mesoscale Models; however, it looks as if it will be just another cold, windy, and rainy weekend for the Lowcountry.