El Niño, the warm phase of ENSO (El Niño – Southern Oscillation weather pattern).
La Niña, the opposite of El Niño. The cold phase.
Oscillation, a repetitive back and forth at a regular interval.
We emerged from a very long run of El Niño which was followed closely by an ENSO-neutral (neither El Niño nor La Niña) period. Here in South Western Canada this means that last winter did not get that cold and it seemed to be a fairly short winter (in my memory anyway). The weather forecasters are now telling us that there is a very good chance that La Niña could bring a very cold winter.
El Niño and La Niña are normal weather patterns that fluctuate back and forth over the years and decades. They are much more predictable than the political adversaries they are blamed on and basically, what we need to do, is pay attention and dress for the occasion!
A little light reading on the subject (perfect for a chilly, smoky September afternoon):
Collins, M. El Niño- or La Niña-like climate change?. Clim Dyn 24, 89–104 (2005). https://doi.org/10.1007/s00382-004-0478-x
- This article is not available for free but has some excellent links to the references that Professor Matthew Collins cites.