Because weather is a really complex event, with lots of small thing influencing each other at cross-purposes. We don't know it well enough to be able to tell exactly what will happen.
The groundhog is known for predicting the weather.
Meteorology
Meteorology
forcasting is predicting the weather. Weathering is tempering the weather
forecasting
true
They specialize in predicting the weather.
Mathematics is not an inexact science. The court did not approve of his inexact answers.
no!
Getting it right.
No, they are not always right.
The forecaster predicted the weather for the whole week