We Could Talk About The Weather

[suddenseer]

Damn it has been cold here. 50's in the morning, and mid 60's daytime. I had to wear a sweater on the bike today!

[N1LAF]

Cold and snow will return soon. Interesting read (now permalinked bookmark)
Arctic Oscillation and Polar Vortex Analysis and Forecasts

Partial content

Summary

- The GFS is predicting that over the next two weeks, ridging/positive geopotential height anomalies centered south of the Aleutians are predicted to force downstream troughing/negative geopotential height anomalies and relatively cold temperatures across much of Canada and the Western US with ridging and relatively mild temperatures for the Eastern US. However, the ECMWF model has been predicting a colder solution for the Eastern US and I describe in the Impacts section my reasoning for favoring the ECMWF solution.

Impacts

- The GFS model is still predicting that generally this pattern of Arctic temperatures to continue. Therefore, based on the GFS forecast I would argue that even if the impacts from the stratospheric PV disruption continue to descend from the stratosphere to the surface that favor cold in the Eastern US and Europe, the cold can only be transient as warming focused in the Barents Kara Seas favors the most consistent cold across Northern Asia. However, the ECMWF model is predicting colder temperatures in at least the Northeastern US than the GFS with the trough axis across North America further east relative to the GFS.

- I favor the ECMWF solution, but I have to admit my reasoning even though is based on ideas that I have discussed before are still fairly speculative so those of a faint of heart might want to skip ahead. As I have discussed previously often the stratospheric polar vortex (PV) center has a reflection in the troposphere. The stratospheric PV is currently centered over Svalbard and is predicted, or a lobe of the PV is predicted, to be centered over or near the Barents-Kara Seas. A polar low in the troposphere would bring colder temperatures to the Barents Kara Seas. An end to the focus of Arctic warming in this region could allow for greater warming elsewhere in the Arctic including near Alaska and possibly over across to Greenland. This would favor an eastward shift of the cold temperatures across North America more consistent with the ECMWF forecast. If I am correct that a tropospheric polar low could set up in the Barents-Kara Seas/Scandinavia region, this does not favor cold but rather mild temperatures for much of Europe.

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We shall see... site worth looking at.