Here's an update for you regarding the latest weather buzz-- that winter weather prowling around for next week.
When we started the day, we were confronted with quite a stark contrast between the two main forecast models that handles the mid-range forecast simulation (GFS and Euro). Look at what they were spitting out:
Obviously the snow-lovers will jump immediately to the possibilities of the Euro-- and not just because it shows the most snow. As blog-watchers will recall, the Euro was the first and most consistent model to catch Superstorm Sandy's track and intensity (quite a feat actually). It's natural to surmise that given two very different patterns, the Euro would have to have the edge.
But, that consistency is going to end up being key to put more stock in the model. The 12z run has come out for today (always a bigger delay in getting the product compared to the GFS), and it is showing a decidedly different pattern than the above image. Here's what we've got now compared to before...
What you're going to see here is that the upper-air happenings tend to dominate and create the surface layer evolution. Here we see a closed low at the 500mb level supported by a strong wrapping area of vorticity (the 'X'). This has fostered a coastal low pressure system that turns into a bonafide Nor'easter with serious snows lining up for nearly the entire Appalachian range.
Now, see what the 12z runs from today have for us:
Here, the upper-air energy hasn't swung through yet, and as such the surface development doesn't take hold until the best energy has already cleared us. We still get storm development once the upper air energy gets into cut-off position, but now the Low is actually off-shore, and becomes more of a foot-note instead of a headline.
The irony in all this is that it's now the hallowed Euro that's now looking more like the 'consistent' GFS, which is still advertising a more pedestrian amount of snow (akin to what's shown above). This brings us to a few points...
1. This situation is still very fluid - and it should be. It's only because of the modern marvel of supercomputing and competing weather modeling that the end-user expectations of the 7-day forecast has shot up. Obviously weather watchers can be trained to take model solutions this far out with an appropriate reservation, but as a meteorologist I can tell you the demand for accurate snow numbers this far out has only increased as a result. It's not just a general curiosity. We'll certainly be monitoring this from run to run to keep tabs of any growing consistency in storm evolution, but we're a far cry from the sort of time-frame where expectations on snowfall accumulations will solidify. There are, however, things that have come more into focus.... which brings me to my next point:
2. Snow is coming - Perhaps the one main consistency in these runs for the past couple of days now is that temperatures will indeed get cold enough to support snowfall, and a snowable scenario will present itself in the tri-state area (meaning not just the mountains this time). Even if the GFS's current solution is the one that verifies, that still means a chilly rain changing over to snow Tuesday night before finishing out lightly on Wednesday. This doesn't have to speak to actual hard accumulation numbers yet if the task is checking off the box for the first snow of the season.
[...now, with that last point, I understand there's a few of you that have November 13th pegged as your contest entry in our "first snow" contest that's sweeping the tri state ;-) Y'alls prayer for validated snowfall is completely understandable. I've practically received bribes to hold off the snow until a few days layer too-- which is also understandable ;-) ]
I'm hoping that updates like this can be more academically informative-- a sort of laying out of the "facts" (or rather what is currently understood). The last thing I want to get into is a situation where someone has made drastic plan alterations a week in advance, doesn't pay attention to any storm updates between now and then, and somehow hold us responsible, as in the "Hey, you said we'd get a foot of snow... what happened!?" even though the forecast changed between the first inkling and a more reasonable day or two before. Not that I'm complaining, but it happens. There has been a movement afoot to figure out how to get the typical viewer a better handle on 'risk manangement' when it comes to looming bad weather out in the long-range, but when it comes down to it, it's really not a big deal. Simply stay with us, and follow the evolution of the forecast on air and online. If the middle of next week a cause of concern for you (as in you know you're traveling and all that), then simply follow things more earnestly until you have to make a decision. I'm pretty sure most of us already do this.
As for our part, we'll continue to keep an eye on things, and chime back in with updates whenever possible.
Thanks for stopping by the weather blog :-)