The developing El Niño - already the strongest on record by some measures - continues to grow and could have profound effects on the weather across North America this autumn and winter.
The naturally-occurring climate phenomenon sees trade winds over the Pacific Ocean, which usually blow from east to west, weakening or reversing with warm water instead spreading eastwards.
This releases heat into the atmosphere which can drive major shifts in global weather patterns.
Impacts in the US and Canada are varied, with a greater chance of a warm and dry winter in northern areas and more risk of flooding rain further south.
There is also some evidence that El Niño can increase the likelihood of disruption to the stratospheric polar vortex which can, in turn, bring snowfall later in winter.
No two El Niños are the same and the impacts are not guaranteed - the odds are just shifted in favour of certain outcomes.
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The eastward shift of warm ocean waters associated with El Niño can cause the Pacific jet stream to move south and extend eastwards, directing rain-bearing weather systems across the southern USA.
This typically leads to wetter winters during El Niño years.