Long Duration Wintry Mix from Sunday Evening Through Tuesday Morning
A storm that will barrel along through Colorado will pass over the Rocky Mountains and move to the southern gulf, where it will send an enormous plume of Gulf of Mexico moisture through the Ohio Valley and into the Mid-Atlantic and Northeast. This is called overrunning, when moisture moves over cold air and produces wintry precipitation. What type it is depends on how thick the layer of cold air is. Right now, the key to the forecast is where the arctic front (the boundary between warm air to the south and cold air to the north) sets up. If it stays further north, we will get mostly rain. If it is near or just south of us, we will get mostly sleet and freezing rain. If it is well south of us, we will get more snow. Right now, it is difficult to say with any degree of confidence what precipitation type we will see. It will most likely change several times throughout the event, from plain rain, to freezing rain, to sleet, to snow. There is the potential for some areas to pick up a significant amount of freezing rain, which is my number one concern with this storm. Amounts of a quarter to a half inch or even more are possible, again, depending on the position of the arctic front.
Article by Josh Karpatkin, MoCo Student staff meteorologist