The Lede
A potentially-crippling snow and ice storm looms for the U.S. South and Mid-Atlantic region this weekend. The meteorological setup is one that has the attention of meteorologists like me. Here’s what we know right now about this emerging, major winter storm.
What We Know Right Now
Winter storms of this potential magnitude can happen in the South, but a perfect set of conditions are needed. One of the key ingredients required is a deep penetration of cold air. The U.S. South will have no problem meeting that requirement. NOAA’s Weather Prediction Center wrote Tuesday morning, “All model guidance shows arctic air making it down to the Gulf and East Coasts, which will clash with southern stream energy to produce a high impact winter storm across the southern tier.”
However, it is important to note that there are still some model differences that need assessment. NOAA WPC went on to say, “However, some model differences still exist with the details of both the southern and northern stream energy. These details will
impact things such as the timing, snow/ice line, and the northern gradient of the snowfall. While these details will need to be worked out over the coming days, it seems almost certain that a significant winter storm will occur.”
Over the next few days, we will be watching various weather models to fine tune where the swaths of snow and ice will be. This is what I do know. It is likely going to be a widespread, high-impact event that starts impacting the Southern Plains on Friday, the Southeast on Saturday, and the Mid-Atlantic/East Coast region late Saturday into Sunday. One thing that also concerns me is that it will likely be a long-duration event. With temperatures well into the teens and twenties, the ice storm on the southern side will be crippling in terms of travel conditions, trees, and power outages. On the northern side, a major swath of snowfall will be featured from Texas through the Tennessee Valley. It will also stretch into the Mid-Atlantic region around Washington, D.C. or Richmond.
Beware Of Your Weather App With Messaging For This Storm
With ice and snow, we need more information from the models. However, here is a cautionary note inspired by Charlotte-based Meteorologist Brad Panovich. Do not get anchored down by your Weather app and its little snowflake icon indicating how much snow you are going to get. Apps are notoriously bad in dynamic situations like this that involve a range of precipitation types. Panovich, who I have long considered one of the best broadcast meteorologists in the U.S., wrote on his social media pages, “Stop looking at that snowflake icon on your phone for this weekend’s totals! Here is the dirty secret your weather app won’t tell you: It has no idea what is actually falling from the sky.” He went on to say, “Why your app fails It sees this chaotic mess, gets confused, and usually defaults to a snowflake if the temp is near 32°. It ignores the complex vertical layers (like a “warm nose” of air aloft) that turn snow into an ice storm or cold rain.” In these situations, human meteorologists are better at understanding the context and preventing you from suffering what he called “forecast whiplash” from your phone app.
Meteorologist Matt Daniel is a former student of mine at the University of Georgia. The Birmingham-based meteorologist pointed out another potential hazard. If there are significant power outages in the South, there could be many people exposed to dangerously cold temperatures in their homes and businesses. That could also lead to use of alternative heating sources and carbon monoxide risks. Other secondary hazards include over-exertion related to snow-ice removal and traffic accidents.
This storm is one to watch, and I am already considering adjusting travel plans to watch my son’s college basketball team, the Oglethorpe Stormy Petrels, this weekend in Tennessee and Mississippi. In fact, I will be stunned if those games even happen.
