Update on stratospheric warming

Still uncertain whether this will have a significant translation to sensible weather at the surface. Temperatures have reached their peak at 10mb of 267K and have started falling rapidly back downward, as predicted by the ECMWF. Multiple date records were broken and the all time record was shattered as well. In addition, records were broken for the rate of warming. However, all this, as amazing as it is, does not consistute a major warming. As defined in my previous post, a major warming is an event in which the mean zonal flow reverses at least as low as the 30-hPa level. So far, the mean zonal flow has only reversed so far as about 25mb.



Compare this to the major warming event in January of 2006:


Notice that -25m/s anomalies reach 30mb, and the mean zonal flow reverses all the way down to the surface.

Now there is no reason that that cant happen with this event, however the ECMWF has been persistent in dropping temperatures down as quickly as they rose, and the current warming was not enough to weaken/split the polar temperature minima very much, and has only succeeded in displacing south somewhat.

A second rebound in temperatures would likely be necessary to achieve a complete break down of the polar vortex. So it is going to be a wait and see game in that respect.

If this is a propogating event, sensible effects at the surface would begin by mid to late February.