Defining consciousness is its own challenge, but one definition that I like (as a layperson) is that it consists of an approximate model of our self, that emerged as the brain recursively modeled itself while attempting to model other's behaviours, a critical trait once group co-operation and adversity became key to our survival.
This seems correct to me, a hurricane exhibits computational complexity, but it does not have a sense of self, and does not use that sense of self to make decisions.
Of course, that sense of self can also be broken down into manual computation, it's just a very complicated computation. For example, a bayesian interpretation of that "approximate model of our self" might define it as a generative model or joint distribution of actions and states, embedded within a markov decision process (MDP). Modeling, or speculating about your self would therefore consist of sequentially sampling from the joint distribution over several timesteps of the MDP.