January 2011

What will January be like?

I've created an analog list based on a subjective look at the overall December pattern and came up with the following years:
1950**, 1952, 1955, 1961, 1964, 1965, 1968, 1981*, 2009

1950 is by far the best match, and 1981 is also a better match than the others on the list. The rest are only mediocre matches, but I have included them to smooth out wild solutions some.

Here was the December pattern we saw in 2010:

Here is the composite of my analog years:

Not perfect, but not a bad match, either. Here was that pattern rolled forward into January:

This is an interesting result. If we had a pattern like that in January, the Pacific Northwest would be very close to major cold and snow. However, there could be a sharp north-south temperature gradient in British Columbia or northern Washington State, with cool, moist Pacific flow south of that. Lots of borderline rain/snow showers in Portland would be my best guess based on that pattern on its own.

However, I'd like to note two major caveats. First, the pattern would obviously not look exactly the same all January, and if we average a pattern like the one in the above image, there would almost certainly be times where the cold/snow made it down to all of western Washington and Oregon. Second, you might notice a subtle difference between the composite pattern and the actual December pattern. It seems like many of the anomalies in the Western Hemisphere are slightly displaced towards the west in the composite compared to the actual. If that remains the case in January, then the actual pattern we'd see would be a slight shift east of what's shown above, which would be much colder for the Pacific Northwest.


On a final note, many of the models and ensembles are now hinting at a pattern not unlike that being shown in my January composite, so I have more confidence that this could show some semblance of reality.