Friday, November 30, 2012

Significant Stratospheric Warming Event Ongoing

A significant stratospheric warming event, or SSW event, is currently ongoing across the lower stratosphere.

The above image shows 70mb values from 2011 and 2012. The green dashed line displays average stratospheric values for that time of year. If we look at the most recently observed line in the stratosphere, we see that significant warming has occurred, with a sharp spike in temperatures now being observed.

While the stratosphere is so high up in the atmosphere, it does have significant implications on our weather now. What the warming stratosphere does is it weakens the polar vortex, which, when the vortex is strong, can restrict cold air from the US. Now that a SSW is occurring, the polar vortex is weakening, and a stronger push of cold air south should begin. However, the presence of the ongoing ridge over the Bering Sea (and the ECMWF's idea of said polar vortex restrengthening over Canada) tells me to be cautious of any incoming cold weather calls.



Anonymous said...

Winter is shaping up to be like last winter.Locals are calling for above normal the next several weeks.No BIG sorms in sight.

Anonymous said...

Yes there really is no big storms in sight, but in sight is only the next week or two. Hopefully the pattern starts changing in mid December when the blocking over the Pacific is expected to start breaking down. I am concerned that the models will keep pushing this back...hopefully not. Until this happens, it will be warmer than normal but I wouldn't assume that we will have a repeat of last year. We can't possibly get screwed two winters in a row, right?!

Anonymous said...

I'm afraid if the source is Weatherbell or something closely related they see the cold blocking signals in every model presented to them because their biggest clients are "energy companies". If you are a snow lover regardless of the fact that you approach everything objectively or you believe the earth is flat and AGW is a total lie as of now the signals are pointing towards a similar pattern like last year but not necessarily a mirror image. I wouldn't think about buying any heavy duty diesel snow removal equipment, buy skis, or arctic winter clothing right now the way things are looking. Blocking patterns have been the exception not the rule for the past 40 years please keep this in mind.