No one claims they have an economic model that can produce absolute accuracy.
But plenty of people claim they have economic models that produce high levels of accuracy for years or even decades on end, which would have you laughed out of the room at a meteorological conference.
All economic models are estimates. If anyone claims that their economic model takes into account all possible factors, and that adherence to it is equivalent to a sort of natural law, then they deserve to be laughed at. But most economic models are simply best-guesses based on some selected variables deemed to be the most likely to be significant.
No, you never said anything about "absolute accuracy." But that's part of the problem; terms like "any degree of certainty" (what counts as a degree of certainty? yes it's a manner of speech, but an uncertain and ambiguous one), or "accuracy" or a "high level" of something are inherently subjective. No one is denying the riskiness of the future; that is not a uniquely Austrian position.
Just the other day I was having a discussion with an Austrian about the price Apple charges for its iPhones. I pointed out that 51% of the iPad 3's cost is actually Apple profits (which judging by their $100 billion cash stockpile and recently announced dividend, they have no useful purpose for), 56% for the iPad 2, whereas only 2% was the cost of Chinese labor. I said that whether one considers that fair or not is inherently subjective, and he said yes, that is the Austrian position. As if by agreeing that price is subjective, I have binded myself to it. No, not at all. It is subjective, and in my mind, subjectively injustified, and thus pressure on Apple to raise wages is justified. But that was a different matter...