The higher the Wildfire Build-Up Index, the hotter and drier the fuels. As the season progresses, the value “builds” until rain reduces it.
In the past, fire managers used the index to predict fire activity a few days out. Our team is now helping to provide an outlook of the build-up index months before the season starts.
To do so, seasonal weather forecast models explore how the index varies under past known weather and climate conditions. Where model predictions are consistently too wet, or too hot, the model is corrected to account for the difference. Even with these adjustments, predicting the index three months into the future remains difficult.
Model accuracy can be improved by understanding how slowly varying parts of the climate system—such as sea surface temperatures and sea ice—contribute to Alaska fire weather.