typhoon/weather forecasting

typhoon/weather forecasting is a messed up business isnt it. hey its not just me but i think almost everybody has some gripe about this. i mean why is it when they say its going to rain.. or sunshine,ot typhoon will hit so and so, the opposite always happen. isnt it an exact science? dont they have these instruments that should actually predict the weather. or is it only in movies where they actually and really predict the weather. i dont know.