Breaking down what a computer forecast model really means

LEXINGTON, Ky. (WKYT) - Weather model or computer forecast model, you've heard that term tossed around quite a bit this past week. But what is a computer forecast model? A model is a computer algorithm which predicts the weather. These models run on supercomputers that compile billions of pieces of data that essentially tells you if you're going to need an umbrella or not.

There are several models that meteorologists use when gathering data for the forecast. With the potential winter storm hitting far southeastern Kentucky this weekend, we've shown you a lot of these "models" on-air. But why?

"We're showing the models to the people just to give them an idea on some of the different scenarios that the computer models are thinking, said Chris Bailey, the WKYT Chief Meteorologist."

There are many common models used in everyday forecasting. American models like the NAM (North American mesoscale Model or GFS (Global Forecast System)... or the GEM (Global Environmental Model).. a Canadian Model. Even the European Model. They're all part of a guide meteorologists use to forecast.

But these computer models aren't perfect either. Understanding why some can be inaccurate can help forecast for what's ahead. "They all have their biases. Knowing the biases and trying to correct them will help you out a lot in the long run," said Bailey.

Biases such as storm track, being too warm or being too cold. These are all things to consider among many other meteorological factors. But Bailey says remaining consistent and giving models time to work the kinks out is best. "Just to try and be consistent, not change from run to run of the computer models and just kind of let things play out. Then as you get closer to an event, either your confidence is going to increase or it's going to decrease on what you already have out."