A New Wrinkle in Weekend Threat

If you asked me what I thought about the weekend clipper system today, again with a gun to my head, I'd still go with the ideas outlined yesterday, but a couple of models are really throwing us a curve here. There is no doubt that in this winter, nailing down details with storms has been very tough to do for pretty much every meteorologist and hobbyist that I know. Part of this I think is due to heading into a new long term regime in the Pacific, and the unique behavior of the sun and the stratosphere. I think all of these factors are really going to test folks in the coming years, and many people may need to refine their methods. We'll see. Anyhow, back to the present. If you simply adjusted for a faster northern stream and generally less amplification with storms (we did get some amplification and very cold weather in January), you'd be on target more often than not with these situations this winter. But now we have something unexpected. A couple of models, the Canadian and more importantly the European (typically more reliable) have indeed trended quicker with the northern stream, which makes sense with the huge drop in angular momentum and the shift to a nina-like pattern globally, but now they are so fast with the northern stream that the upper level system which brings the weekend clipper through splits, as the southern half of the upper trough cannot keep up with the momentum of the northern stream. This piece then forms a strong area of low pressure near the east coast Sunday, and since the clipper has gone through, there is fresh cold air in place. The end result is a large snowstorm for everyone from Virginia to the Northeast (central PA and western NY the cutoff on the western edge). So in a weird way, the fast flow actually helps out here. Now this is similar to what some models were doing a couple of weeks back when they showed a major Ohio Valley storm. As we all saw, that wound up weaker and farther east, and any adjustment like that here may kill the chance of a notable storm, even if the southern piece gets left behind. The key to breaking off the southern piece lies in a strong ridge that the Euro and Canadian models show in the Rockies, which leans northeastward into central Canada and helps force the split. If this ridge isn't as strong or positioned just right, you get no split or a much weaker one.

Bottom line... I have plenty of reasons to doubt this big storm idea right now given how this pattern has tended to behave this winter. But, as mentioned, this winter has thrown us for a loop before, so I will fully admit I could be wrong here. We'll have to see how the next few model runs go and see if my pattern expectations are off here (which I know most of you reading are hoping for hahaha).

By the way, what all of this also does if the European and Canadian models are right is bring about a colder pattern again just in time for early March as well after a warmup next week, so a lot is going on here.