You’ve probably heard of the jet stream. What is it? Its a current of fast moving air higher up in the atmosphere, near the level that commercial airplanes cruise. Why is it important? The jet stream does a few things. First, it usually marks the boundary between mild sub-tropical air and cold arctic air. Second, the jet stream helps to steer the various storm systems. What does that have to do with this week’s weather? The jet stream will take a dive just south of us and remain there for most of the week. That’s a big change from most of this winter so far. That means not only will we be on the colder side of the jet, but one storm system after another will pass just south of our area this week. We’ve got just about one storm system a day through Thursday.
The first arrives Monday and it looks more likely that this one will be the most significant. Normally a storm system passing this far to our south and east wouldn’t have a huge impact on the area. However, strong northeasterly winds will help to push moisture well west of the center of storm. That combined with mild ocean temps will lead to ocean effect snow. As of Sunday morning it looks like we might see around 4-6" in the greater Boston area on Monday with the possibility of much more snow over parts of the South Shore, the Cape and the Islands where ocean effect snow will add to the totals.
That’s just storm #1 and it moves away from us Monday night. The next few systems will keep at least a chance of snow showers or flurries in the forecast through Thursday. Right now it looks like we won’t get much more additional accumulation of snow beyond Monday night, but stay tuned. Finally, the jet stream will push an arctic front our way on Thursday. As you might expect with an arctic front, it gets cold!! Temps will drop to the low teens Thursday night and won’t rise above the 20s Friday afternoon. The cold air sticks around through at least the early part of the weekend. So, any snow we get early in the week will likely be around for awhile.