The basic force that causes wind is a difference in air pressure. Air naturally flows from high pressure to low pressure. In the atmosphere, it does this in a circular way due to Earth’s rotation. Air spirals outward from high pressure and inward toward lower pressure. This may sound complicated but it is relatively to calculate mathematically so computer models can forecast this quite well.
But wind is actually very hard to forecast because of the fact that the atmosphere has three dimensions. Air moving up and down can greatly influence surface winds. Afternoon thermals or sinking air from upper level disturbances can add a tremendous amount of turbulence to the air and bring down wind energy from upper levels that can unexpectedly turn a gentle breeze into a very windy day.
And the problem is that these vertical winds are very difficult to measure and model. Our wind forecasts often include a certain amount of experience and “gut feel.”
Meteorologist John Wheeler