Although they're interested in forecasting future events, Lin and his group also want to know if MC2 can first demonstrate a gift for hindsight. We want to see if MC2 can perform what we call a 'hindcast' of the precipitation which led to the Saguenay flooding.
Past performance helps a lot in risk management decisions.
Lin explains that a hindcast is the computer simulation of an event which has already occurred. MC2 works by starting with routinely available observations of the atmosphere at a specific time. If we want to know what happened at a particular place and time, we set up the model grid over a region which is much larger than the area we're actually interested in. That area could be most of the country. We furnish information on the atmospheric conditions such as temperature and wind velocity at the boundaries of the model, to get the model started.