Rare: Sudden Stratospheric Warming in the Southern Hemisphere — cold weather coming?

Right now a very rare southern SSW (Sudden Stratospheric Warming) is taking place, possibly peaking today or this weekend over Antarctica. In the Northern Hemisphere SSW’s happen more often and in the month afterwards, wild polar blasts like the “Beast from the East” can peel off. So somewhere way up at 10hPa or 30 – 50 km, there is an area that’s warmed from -60C to close to zero. The warming up high throws a spanner in the normal jet streams and weeks later, down at the surface, blobs of cold air from the poles may end up wandering far from “home”.

We (as in Africa, Australia, Argentina, or New Zealand) may get bumper snow and severe frosts, or we may not. Some researchers are getting excited and are using the word “historic”.

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These are rare over the Southern Hemisphere — due to Antarctica being shaped like a circular cheesecake right over the pole and surrounded by water. The geography is cleaner and simpler than at the north pole, and that generates a strong circumpolar jetstream. The strong pattern normally stops these sudden warmings up high which occur with wandering jetstreams.

In the Southern Hemisphere there have only […]