Winter Storm Watch Posted for South Louisiana
The National Weather Service has posted a Winter Storm Watch for all of Southwest Louisiana. The aerial outline of the watch area you can see below. You can probably figure out what a winter storm watch is just based on your southern knowledge of how tornado watches and hurricane watches are issued.
Basically, "a watch" means there is the potential for winter weather conditions, including snow and ice accumulations to occur within the watch area over the next 12 to 48 hours. Does it mean there will be snow and ice in the area? In most cases probably. What a watch doesn't define is the amount of frozen precipitation that could fall or accumulate.
Snow and ice, unlike hurricanes, are hard to track. And the accumulation of snow and ice is even harder to forecast. In fact, like rainfall, amounts can vary significantly from one locale to another, even if those locales are only separated by 10 or 20 miles.
But in the broader sense, I think it's a safe bet to say that almost all of South Louisana will see some form of wintry precipitation. Right now the speculation from the National Weather Service is that will come in the form of freezing rain beginning late Sunday night and that could turn to snow during the daylight hours of Monday.
Freezing rain occurs when moisture falls as a liquid and then freezes on contact with a surface area. This means a thin sheet of ice or glazing of ice. On the roadways, these "sheets of ice" are almost impossible to detect until you're spinning wildly out of control in your vehicle.
Bridges and raised surface roadways will begin to ice over first. The fact that this weather event is expected to begin in the dark hours of late Sunday or early Monday morning makes this aspect of this kind of weather event extremely treacherous.
Ice accumulations can also weigh heavily on tree branches and powerlines. This is why power outages are common in ice and snowstorms. So you might want to pull out the hurricane kit, minus the bug spray, for what could be an extended period of time without power.
As of early Saturday morning, it does appear that the greatest threat of ice and snow accumulation will happen the further north and west you go from Lafayette. That's not saying it won't get slick in the Hub City, we're just saying based on forecast models Alexandria, Shreveport, and Monroe will likely have a tougher time with this storm than Lake Charles, Lafayette, and Baton Rouge.
Based on the forecast as of 0500 CST February 13, 2021, the time and date are significant because this forecast can and will change quickly. So don't read this with your coffee this morning and think you know what's going to happen on Sunday night and Monday.
Here's what forecasters think will happen later this weekend.
Temperatures in South Louisiana will hover at or just above the freezing mark, 32 degrees Farenheight, for most of Sunday night and early Monday morning. When the temperature drops below that 32-degree mark will be the key as to when icing issues will begin.
Some forecast models have freezing rain beginning after sunrise on Monday. Some models have freezing rain and sleet beginning shortly after midnight. It's all incumbent as to where the "freezing line" situates itself and how quickly it moves southward.
The gusty winds will play a part in the accumulation possibilities as well. If the precipitation falls in a very light mist, it's possible the winds could help evaporate that moisture before it has the chance to freeze, especially if the temperatures are right at the freezing mark.
It does appear that during the day on Monday much of South Louisiana will see freezing rain turning to sleet and eventually snow. The bulk of the precipitation will occur between 7 am and 4 pm based on National Weather Service guidance.
There could also be a second wave of frozen precipitation falling across the area on Monday evening. That precipitation will likely be in the form of snow or sleet as temperatures in the upper atmosphere and at ground level will be below freezing.
The threat of precipitation should end early Monday evening, however, that is when the really cold Arctic air will invade the area. Temperatures on Tuesday morning could be in the upper teens by sunrise on Mardi Gras. Sunny skies should help melt away any ice and snow accumulations during the day on Tuesday as temperatures will rise into the middle 30s.
Our advice to you. Take care of securing issues with pipes, plants, and pets during the day to day and during the early part of the day on Sunday. You might want to visit your grocery store to pick up a few extras, this should not be a long event, but still, you might not want to get out on the roads on Monday or Tuesday so get some extra Pop-Tarts and pray the Internet doesn't go out.
You could always put on a big pot of gumbo, which would certainly keep you warm on the inside. Just make sure you don't violate any of these, okay. We don't want to have to send the Gumbo Police to your house on icy roads.
10 Commandments of Gumbo