Meteorologists say that when they design an accurate mathematical model that can describe all the complex details of the atmosphere, they can make a completely accurate weather forecast. This is actually a specious boast, and this boast can never be proven wrong. Because as long as there is an error in any weather forecast, inaccuracies can be found in the relevant mathematical model. 
this statement of meteorologists is meaningless.
 Modern weather forecast has reached an accuracy of 85%