Can someone point to a explanation or provide one on how the probability of 3 things happening ("We estimate about an 80% chance that this El Niño will peak with a maximum Niño-3.4 Index of at least 1.0 °C, a 50% chance of at least 1.5 °C, and a 20% chance of above 2.0 °C.") add up to greater than 100%? 80%+50%+20% is 150%.

Thanks