The September QBO figure has now been issued by NOAA. As expected the QBO is rapidly transitioning from easterly to westerly.
The September figure is -9.9 up from -20.4 in August. I would expect the October figure to be somewhere close to zero with a positive figure by November.
https://www.esrl.noaa.gov/psd/data/correlation/qbo.data
So we should be in the westerly QBO this winter. I am not sure how long it takes the atmosphere to adjust to changes in the QBO so we may still be somewhat influenced by the legacy of the easterly QBO, at least for the first part of the winter
Of course the QBO is only one factor that can influence winter conditions.
Looking at years where we transitioned from easterly QBO to westerly QBO in late Autumn the closest match to this year is probably 1977. December 1977 was warm but January and February 1978 were both rather cool. The cool conditions continued right through until August. The middle part of 1977 was also very cool so completely the opposite to what we had this year. We did have weak El Nino conditions in the winter of 1977/8. Solar activity was much higher than it is now.
There are a few other years where we transitioned to westerly QBO a little earlier than this year i.e. in the late summer / early autumn. These were 1963, 1982, 1987, 1992 and 2010.
Dec 1963 - March 1964 was chilly
Dec 1982 - Feb 1983 was mixed - cold December and very cold Feb but mild January
Dec 1987 - Feb 1988 was mild
Dec 1992 - Feb 1993 was mixed - Dec cold but Jan very mild
Dec 2010 - Feb 2011 was also mixed - Dec very cold but Feb very mild
So no real trend there. But it does show that where we transition into the westerly phase of the QBO just prior to winter, it is still possible to get some quite cold spells of weather during the winter, more particularly in December (4 of the 6 years mentioned above).
Originally Posted by: Global Warming