How can meteorologists predict weather forecasts with accuracy? After how many days out do forecasts lose accuracy? What factors make weather forecasts hard to predict?
In: Earth Science
>How
As mentioned, using lots of data points (and an increased understanding of their cause and effect) fed to computers. But also note that answers aren’t given explicitly but as percentages. So imagine feeding data 100 times through your computer, which also accounts for chaos/randomness. This means you’ll get 100 different forecasts. If 60 of them predict rain in a certain area and 40 don’t, you’ll have a 60% chance of rain. (How they handle 50/50 may change as viewers want answers, not a coin flip.)
>After how many days
Also as mentioned, about 3 days
>What factors
“Weather also has two additional properties that make forecasting even more difficult. First, weather is nonlinear, meaning that it abides by exponential rather than by arithmetic relationships. Second, it’s dynamic — its behavior at one point in time influences its behavior in the future.” -*The Signal and the Noise*
When dealing with exponential relationships, time is only compounding this problem, hence why 3 days has been mentioned.
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