Monday, September 24, 2012

Negative QBO Helping Prospects For Negative NAO In Winter

I have been watching the QBO and found that both monitoring levels (30mb and 50mb) have been trending negative. This bodes well for the possibility of a negative NAO this winter.

But first, 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. Let's take a look at what the NAO has been doing recently.

Look how negative the NAO has been recently, with only 3 or 4 jumps into positive territory in the past  4 months. 2 of those 'jumps' into positive territory were minimal strength! 

Could the QBO be to blame?
Most certainly! The QBO has been very negative for much of the time the chart above was recording (June 1 to present). But the QBO is not alone. The AMO also helped, the effects of which were seen in this recent post. The presence of a positive AMO has helped to warm the waters in the north Atlantic. 

It's like all the pieces are coming together for the Northeast. Will this be the year of winter's revenge? It's certainly shaping up that way.

Andrew

1 comment:

Anonymous said...

How would the midwest and Ohio Valley do in terms of snowfall and cold if this pans out? Would it be cold/dry or cold/snowy?