We can be very sure a heat wave is not going to hit 500 degrees Farenheit, on Earth as we know it. We can also be sure that heat waves are going to continue to extend their RANGE of possible states in direct correlation with global climate energy increasing. And we are seeing exactly this.
We will also see that as the energy in the climate increases, our ability to predict into the future gets worse rather than better. Not because we got dumber, but because the chaotic system is becoming more chaotic as energy is added. The more extreme it gets, the more capacity it develops to confound projected outcomes due to chaos's sensitivity to initial conditions.
If you wanted the ability to predict more accurately, the only way to get that is to cool off the globe and take energy out of the system. It's the energy that's driving the chaotic behavior.