The rapid intensification that turned this week¡¯s Typhoon Rai into the strongest storm to hit the Philippines this year surpassed all predictions, forecasters said, leaving nearly 400 people dead and almost a million displaced.

While it¡¯s unclear exactly how global warming is affecting the intensification of such storms, the U.N.¡¯s climate change agency has found it is ¡°likely that the frequency of rapid intensification events have increased over the past four decades¡± as temperatures rise.

Before Rai underwent a process of rapid intensification, forecasters at first warned of a storm that could bring ¡°considerable damage,¡± with winds of up to 165 kph (102 mph).