Predicting Dry Lightning Risk Nationwide

Meteorologists developed two formulas to predict the probability of dry lightning throughout the continental United States and Alaska and parts of Canada. Predictions are made daily and are accessible through the web at http://www.airfire.org/tools/daily-fi re-weather/dry-lightning-probability. The emphasis is on the western United States, where dry lightning is a more common occurrence. Predictions are based on identifying days on which lightning is expected and separately determining whether there is likely to be at least 1/10th inch of accompanying rain. The formulas are run with the latest North American or Alaskan weather forecasting model and forecast dry lightning probabilities for about three days into the future. This could allow managers lead time to move firefighting resources and personnel into position ahead of a high risk time. Work on a new Joint Fire Science Program (JFSP)-funded project will incorporate fuels information into the models and improve the precision of rainfall amount forecasting.