I wouldn’t bet the farm, but there is some evidence within the model guidance that suggests another round of some flurries and sleet may be possible on Wednesday morning.
Much like this last time, accumulations are very unlikely.
Unlike last time, there won’t be much moisture, so if you see any precipitation at all – liquid or frozen – consider yourself lucky.
For snow, it looks like some pretty light drizzle is the most likely scenario, but let’s investigate the data…. And see if physics can be our friend!
Quick look at the data
Looking at the above graphics, I know what you may be thinking. First, Nick those maps are way too small and second, Nick, you’re getting my hopes up for two specs?
Well yes and no. I don’t mean to get anyone’s hopes up that anything will actually happen. Because it most likely will not amount to much. However, I also don’t want to miss an opportunity to give everyone the heads up that if you are up and moving Wednesday before lunch and happen to look out the window, you may get lucky enough to see a quick flurry or little patch of light sleet.
The thing that intrigues me the most about the setup on Wednesday is shown in the skew-t charts in black above. Those show two things: super dry air and the Omega in the DGZ.
The is a stout layer of very dry air is also above freezing. That means that anything frozen falling through that layer is likely to melt or sublime. However, because it is so dry, if enough precip falls into the stout layer of dry air, it will moisten it up. And as it does so, cool it down. And that process could lead to a column of air that would support allowing a few flurries to make it all the way to the ground.
But it will have to precipitate hard enough to moisten up that layer, in order to cool it down.
That is where the Omega comes in.
Looking at the data above, the HRRR and the NAM-3km data shows some Omega within the DGZ (the dendritic growth zone, the area where snowflakes are made). That means there is forcing and ascent within that section of the atmosphere. And those are two things you need to make precipitation. The other is (a bit obvious) moisture.
Here is a larger view of the HRRR data. It shows Omega in the DGZ as well as the red and green lines close together. That is an indication that the atmosphere in that area – about 15,000ft up – is moist. So, to unpack this and re-pack….
In this model guidance, it is suggested that there is a section of the atmosphere about 15,000ft up that is moist – though not fully saturated. This is the same area (roughly) as the DGZ. So, the atmosphere is moist within the same area of the atmosphere where snowflakes can be made. But just because it is moist, doesn’t mean you will make snowflakes. you need some forcing or ascent to occur. You need the atmosphere to try to shove more moisture into that zone than it can hold.
And that is where you look at the Omega. If it is purple-ish/pink on the left hand side of the chart, you’ve got some. And in this case, we do.
Looking at the raw data, I would argue, there is probably not enough Omega to create enough snow to overcome the dry air below in this one Skew-T. But this is just one Skew-T. If we sample other areas, I’m sure we are bound to find one or two spots where there is enough Omega to build enough snowflakes to overcome the dry air below.
That said, is there enough to overcome the warmer air below? To stay as snow? That is the million dollar question. And I don’t have the answer. I need more data before I can jump on board with an answer about that.
For now, I think drizzle will be the main form of precipitation.
The Bottom Line
Chances are there will be a few patches of drizzle on Wednesday morning and into the early afternoon. For now, it look slike temperatures will be at or above freezing while this is occurring, so travel issues won’t be likely.
That said, some spots may have wet roads and you may have to use your windshield wipers a few times. There an outside chance parts of the area may still be at freezing when this occurs, if so, freezing rain may pose a short-term problem for handrails and exposed, elevated surfaces. And if you’re lucky – really lucky – you may be one of the few that sees a light flurry or patch of light sleet.
