Tracking a Snowy Sunday?
First, it's too early to say anything set in stone. Bummer, I know. Now that we have that out of the way, let's talk about what's going on.
As weather forecasters, some of our best tools are "computer models," and for this weekend, some of them are getting a bit rowdy. These models use mathematical equations to represent what's happening in the atmosphere. There are several we like to look at, including the GFS, CMC (Canadian), and the ECMWF (European), I'm going to put a couple different pictures in here to show you what we're looking at.
The time frame we are considering is Saturday night through Sunday.
The first model to show the potential for precipitation, most notably snow, was the ECMWF, this past Tuesday morning. It was the only model bringing in much of anything. However, by the afternoon run (this model is updated twice a day), the rain and snow were kept to our south. That's the same way it looked this morning:
On Tuesday, the ECMWF was the only model bringing in any precipitation. However, on this Wednesday morning, the CMC and the GFS have flip flopped with the ECMWF.
In this model, the low pressure system rides much closer to the seaboard. This situation would bring us some measurable snow. This model is forecasting about 6" of accumulation.
Penn State University e-WALL
The Canadian Model does bring in significantly colder air. This model also brings in a fair amount of precipitation, like the GFS, however they still have some pretty big differences.
Over the next couple days we will be watching a couple things closely. We need to watch two areas of energy, one to the south and one to the north. How, these two pieces of energy, "phase" or combine together, will greatly impact our weekend weather.
If the southern energy (basically just an area of low pressure) and the northern stream of energy come together to our west, this will bring more moisture to our region. As low pressure develops off the east coast, it will draw in colder air from the northeast. This northeasterly cold flow is where we get the term nor'easter.
The ingredients will be in the atmosphere for snow this weekend. At this point it is too difficult to tell whether they will come together in the right amounts at the right time. This is what we'll be watching very closely over the next couple days.
As the weekend nears, these models will come into more agreement, one way or the other, creating more confidence in the forecast. I'm looking forward to the next couple of days!