I havn't seen this posted anywhere yet so I thought I'd drop it here for all to see.
http://www.theweatheroutlook.com/twooth ... +2016%2F17
Tentative weather prospects
It's a long way off but are there any early pointers to how winter 2016/17 may turn out? Independent meteorologist Matthew Hugo, BSc, FRMetS, RMet takes a look at what the latest data is suggesting.
After an exceptionally unsettled winter last year, primarily due to the influences of El Nino and the QBO (Quasi-biennial Oscillation) phase, the coming winter is likely to have different ‘foundations’.
There is some uncertainty over the likely phase of ENSO (El Nino-Southern Oscillation) for the winter period, but a repeat of last year's ‘strong’ El Nino is not expected.
At the moment ENSO-neutral conditions are in evidence, if not just with a slight trend towards La Nina.
La Nina is favored to develop during the rest of the northern hemisphere summer, with an approximate 75% chance that this will be maintained through the autumn and winter.
When coupled with an easterly phase of the QBO the coming winter may turn out significantly different to the last one.
Whilst there is always an uncertain connection between ENSO and the weather across our region of the northern hemisphere, it is expected that a weak La Nina event wouldn’t aid in strengthening the northern hemisphere’s polar vortex like the El Nino event of last year did. A weak La Nina can promote more in the way of northern blocking through the winter period, but this is certainly an uncertain prediction at any time due to other factors.
The QBO (Quasi-biennial Oscillation) phase this winter is expected to be opposite of last year with an easterly phase expected. Without going into the details of the QBO too much, essentially think of the QBO phase as a system that can facilitate the development of a more potent northern hemisphere polar vortex. A westerly phase QBO essentially adds more ‘fuel’ to the overall winter-setup, whilst an easterly phase of the QBO is known to promote a more disorganized polar vortex. The more disorganized the polar vortex is through the winter period the greater the likelihood of colder outbreaks and less in the way of stormy conditions.
Sunspot activity has been declining since a peak around the winter of 2014/2015. It is no surprise that the severe winters around 2009 and 2010 did coincide with a particularly noteworthy solar minimum, as can be seen on the below graphic. Whilst the connection between solar activity and winter weather is a vague one the general decline in solar activity is set to continue through this coming winter period.
Early indications suggest the coming winter may be significantly different to the last one. The combination of lower solar activity, a weak La Nina and an easterly QBO phase may favour a less cyclonic pattern and perhaps increase the risk of colder outbreaks.
Take a look at the current and upcoming Winter forecasts or Autumn forecasts and any weather alerts or news.
1 post • Page 1 of 1