The causality is unidirectional; there is no entailment in the sense that a period like this could occur without global warming or without global warming effects being responsible for this particular episode.
However, the prior probability of this event is influenced by the warming of the system overall. The expectation that an event like this will occur in a given season is higher if you have a warmed planet than not.
That doesn't mean that it will happen, or that if it happens it's because of global warming. If there is global warming this event is more likely and should be expected more often.
The causality is unidirectional; there is no entailment in the sense that a period like this could occur without global warming or without global warming effects being responsible for this particular episode.
However, the prior probability of this event is influenced by the warming of the system overall. The expectation that an event like this will occur in a given season is higher if you have a warmed planet than not.
That doesn't mean that it will happen, or that if it happens it's because of global warming. If there is global warming this event is more likely and should be expected more often.