The Main Event - Oh what a mess it will be

Well, this time I'll cut to the chase since the weather is already causing some issues.

Snow has already begun falling from the Tennessee and Virginia borders all the way down to the Triangle. Raleigh has not received any snow yet because the snow is evaporating before it reaches the ground again.

What to Expect: P-Type

So, unfortunately with this setup is that the cold air is present but warmer air is coming. If the air were going to stay cold all the way up, this could be a pretty good snow event. However, the atmosphere between 1-2 kilometers is going to be warm again due to some southerly wind components.

Initially, tonight (Sunday, 2/14) overnight precipitation will be all snow in Raleigh. Not much accumulation is expected and here in Raleigh we could see up to 0.25" of snow. If the temperature stays cold in the mid-troposphere then we could easily see more than that, but model data suggests that the warming is very likely to take place.

Early tomorrow morning (Monday, 2/15) a couple hours before sunrise the precipitation will switch over to more of a sleet/snow mix due to the warming aloft. This will likely last for a couple hours.

Around sunrise tomorrow morning, the surface layer will be below freezing however the warm advection aloft will have been sufficient for melting frozen precipitation before falling to the surface layer. At this time the mix will be more of a freezing rain/sleet mix for a couple hours before switching to a primarily freezing rain event into the early afternoon.

Throughout the afternoon the precipitation will switch to liquid rain. Freezing rain at the surface late in the morning will warm the temperature to the freezing point, then warm advection will warm the surface to above freezing. By that point though the damage will already be done and roads will be a mess.

Accumulations

For Raleigh, we could get up to about 0.25" of snow before sleet begins. Sleet added in will give us between 0.3-0.5" probably. Freezing rain after that is really a toss-up. Some models have us receiving more than 0.05" of freezing rain, and a couple others have us receiving almost 0.25". P-type is crucial for accumulation, and p-type is difficult to determine for this system.

Hazards

As is the case again with winter weather, road conditions will be pretty bad. They will likely clear up a bit tomorrow night as the rain will work to melt what precipitation sticks. In this case too, because temperatures will warm up, I do not expect power outages to be much of a problem either even though there will likely be some short-lived ice accumulations.

One hazard which may be unanticipated by the general public with this type of system is flooding. Icing could block paths to city waterways, and rain falling on top of that will have difficult at first for the rain to melt through the layer. Flowing water on top of ice is a horrific combination for travel, so please stay off the roads tomorrow if you can avoid it!

Class Cancellation

Well, I said it by word of mouth earlier and it doesn't mean as much now that the University has wisely made a decision about morning classes tomorrow.

Classes before noon cancelled, and dozens of counties closed school.

Going further: Tomorrow morning the University will cancel the rest of classes tomorrow.

Class will likely remain as-scheduled on Tuesday

I hope everyone has an awesome day off tomorrow! Go Pack!