Suppression Depression or Major Storm Threat?

If you're a snow lover living in southern New England you're probably not all that happy with how winter has started. We have had plentiful cold at times, however, we've also had our share of warmth with very little of the white stuff. As we head into the second weekend of January some opportunity exists to bring some excitement to snow lovers. Some work needs to be done to make this happen, however, speaking from a synoptic stand-point (which will be the premise of this post) this weekend will be extremely favorable for cyclogenesis (development and rapid strengthening of a low pressure system)...it's just a question of where the system tracks. This will be answered over the coming days. I will be using the 18z run of the GFS forecast model from January 8th (as this is the most current run available during the composition of this post) to illustrate the key features we will be focusing on. I will also discuss the latest GFS ensembles which will be used to yield what interest level we should have in this event.

Over the next few days the Pacific-North American (PNA) is expected to become more positive in nature as a ridge builds into the western United States. Let's also note the piece of energy to the east of the ridge axis:

The Arctic Oscillation is also expected to DRASTICALLY drop over the next few days. In the animation below notice the very high pressures which develop over the Arctic. This is in response to the major sudden stratospheric warming event which occurred and led to the split of the polar vortex:

This negative AO coupled with the positive PNA will try and dig a trough down into New England. As this occurs the piece of energy (highlighted in the first image) will be progressing across the country. The northern and southern branch jet streams will be phasing (interacting) over the northeast. This will provide sufficient energy and ingredients for a rather potent low pressure to develop:

The jet stream will also be rather strong and this will lead to a very complex (so to speak) atmosphere this weekend with alot of moving pieces. Forecast models have been consistent in some energy moving through the northern stream which 1) may interact with the southern stream energy and further enhance the strength of the storm and 2) may also suppress it south of New England. There is also a rather strong high pressure to the north which could suppress the system:

The latest ensemble run of the GFS, however, still shows decent potential for a snow event here in southern New England. There is certainly a quite a bit of details to iron out through the week, but for snow lovers there is some hope!