Positive QBO Values May Throw Wrench Into This Winter

Latest analysis of the Quasi-Biennial Oscillation reveals positive values beginning to spread down to the surface from the upper levels of the atmosphere.


But before we analyze the QBO, one must know: WHAT IS THE QBO?
QBO (Quasi-Biennial Oscillation): The QBO is an indice measured in two levels of the atmosphere. These two levels are the 30mb and 50mb levels, and are measured by the direction and strength of winds in those levels. For instance, the POSITIVE QBO is found in WESTERLY winds, while the NEGATIVE QBO is composed of EASTERLY winds.

Recent measurements of the QBO at both the 30mb and 50mb levels are negative, indicating easterly winds. The presence of both levels recording negative values tells me this is not a quick change from positive, but a trend.

The QBO has a big impact on the North Atlantic Oscillation. Without getting into the technical stuff, just know that a negative QBO can help enhance the negative phase of the NAO.

The circled portion in the image above is pointing out positive anomalies, shown as gray across the image. White spaces indicate negative QBO values. Taking a look at the QBO, one can see that thee positive anomalies have been pushing down in recent weeks. Looking at history, this downward propagation of positive QBO anomalies may very well continue. If this propagation does continue, I would expect it to hit the 30mb and 50mb regions by the time winter rolls around- a bad sign for those who love snow.

BUT HOPE IS NOT LOST!

A lack of Arctic sea ice, combined with a warm AMO is helping to make the Arctic Circle much warmer than normal. This increased warmth could very well create blocking, possibly over Greenland, to create a negative AO. With luck, a negative NAO may also come to terms this winter.

This is only a small development, and I am not concerned at the moment. However, if winter comes and the QBO has flipped to positive, I will have to reconsider my winter thoughts.

For those not technical about weather: Expectations for winter remain on track as seen in my Official Winter Forecast. However, if this QBO index goes positive in time for the winter months, this snow potential may be changed for many regions.

Andrew