How to predict weather?
To ‘correctly’ predict the weather would require a clairvoyance that our best meteorologists have yet to divine.  In other words, they’re often quite wrong. 

Weather prediction is very much a data limited problem. If you had access to each and every variable that contributes, you’d do a great job. The problem is one only has access to a subset, and the mechanics are still not fully understood. I’m not a meteorologist but I also suspect the sensors we have are sparse. I’d want temp, humidity, wind speed, and barometric pressure at 100 meter intervals both parallel and perpendicular to the earths surface, plus historical data, rate of change, ocean temp and currents, and the airspeed velocity of every unladen swallow in the area.