How will Climate Change Affect Weather Forecasting?

Since the inception of numerical weather prediction more than 60 years ago, efforts to improve forecasts have focused on advancing model physics, numerics, and resolution; on developing more and better observations and improved data assimilation; and, in recent decades, on finding better ways of quantifying forecast uncertainty. Current forecast skill at planetary and synoptic scales does not seem so very far away from Lorenzian theoretical predictability limits. But such limits depend, among other things, on characteristic growth rates of unstable disturbances and these and other constraints on predictability will depend on the state of the climate. Using simple theoretical scales for the growth rates of various kinds of disturbances, I will make some educated guesses about how the predictability of various kinds of weather phenomena might vary over the next century, backing these guesses up with actual calculations for a limited set of phenomena. I will end with a vision of what a Bosartian map discussion might be like in the year 2100.