Thursday, June 6, 2013

Altostratus Coming At Us

The weather systems move slower in the summer. The jet stream is turned down a notch and the disturbances in the upper atmosphere move slower as well. The high level moisture painted in #1304 "Cirrus and Contrails" had thickened into altostratus overnight and was approaching from the west. Some cirrus was still apparent right above me but the main interest for me was the arc of altostratus crowded behind the deformation zone - my favourite forecast tool. This is a typical sequence of events for any approaching weather system. By the time I finished the sky was overcast altostratus. The title is my attempt at poetry...

Weather disturbances will move even slower with climate change. If one considers that the north is warming faster than any other part of the globe, the temperature contrast between the equator and the poles must become smaller. The jet stream is just a upper atmosphere reflection of this temperature contrast. As a result the jet stream must weaken and the systems must move slower. It isn't rocket science - it is actually more complicated than that.

1 comment:

Aleta Karstad said...

This is a great explanation of clouds, and weather patterns affected by climate change, Phil - great painting too!