Quick! Man the Snowplows!

Well, I mentioned how tricky this setup was for the upcoming storm, and while still, even this close to the event, there are some notable differences in modeling, I think things have definitely trended MUCH more favorable for a nice storm for many in the East, including places that have seen very little this winter. Let's go back to what we were looking at yesterday. I discussed how the key was an upstream "kicker" shortwave that was expected to move things along and push the bulk of this storm farther east. That had been the trend all winter long, and honestly, there was nothing suggesting that the northern stream would not continue to assert its dominanace, so that was the idea to go with. However, for the first time this season, things are trending slower / weaker with the northern stream flow, in that the kicker shortwave is weaker on today's models, along with a more solid ridge out west, and this allows the storm to come up the coast farther west. Let's look at a couple of maps. The first map down below is the GFS from yesterday, and I want you to take note of the shortwave in central Canada, highlighted in red. The second map is today's GFS, and look at how much weaker / farther north that shortwave is, which means less of a kicker, and BAM. That is a big key to all of this, and why models have come west, so please take a look at this. Now, you may ask. What about the NAM? This is the short range model that typically is the go to model at this range, and it is way east, showing virtually nothing for the big cities other than Boston. It is closer to what my thoughts were yesterday, so why do I discount it in this case? The reason is again because of the shortwave up in Canada. This shortwave this morning is up in northwest Canada, which is a location that I would tend to think the global models can resolve better than the NAM, and pretty much all models are lined up against the NAM at this point, which is tough to ignore. The final map below is my updated call, which as you can tell from this discussion, is a lot different than yesterday's guess. I'd also add that yes I can see a 12+ area in eastern New England, but wasn't confident enough to put it on here yet, so will call it 6-12 with local amounts of 12-16 and be done. I am going for a sharper precip gradient than the global models and perhaps still a little east of some of them. What can go wrong? Well, even at this short range, still a lot! The NAM could still score the coup, but we'll see if it shifts west any later today. Once the Canada features are more in the core of the NAM's grid, I would assume it does indeed pull west some. I won't be able to update the map the rest of today, since I will be out this evening, but will try to throw out last minute thoughts when I am able to. It does seem that if changes need to be made, it is more likely to be in the direction of increasing the amounts.