Stratosphere update: propagation

The stratospheric warming is very much on track, with a second maximum showing up in the last week around 30mb, and zonal mean wind anomalies under -30m/s. I would expect another antinode to show up in the next week, close to the tropopause (See my previous post) . Already the AO has taken a tremendous fall, with the latest down to -3SD! This -AO will not overlap the NAO very much, but will likely still influence a slight -NAO for the next couple of weeks. The AO will fall a little more before going though vacillations between -1 and -3SD over the next 4 weeks.



Despite this development, the Pacific will remain unfavorable, with a positive EPO / negative PNA pattern in the next week. This supports eastern US warmth, and it will only partially be countered by the favorable polar field.