Volcanic Ash Advisory Centre VAAC Montreal monitors and advises on volcanic ash transport. VAAC Montreal's area of responsibility includes Canada; Greenland & adjacent Arctic waters; and the North Atlantic Flight Information Region (Gander, Newfoundland FIR). VAAC Montreal uses satellite imagery; in combination with computer models and other observational data, to forecast the evolution of a volcanic ash cloud. VAAC Montreal products include both Volcanic Ash Advisory Statements and Graphical forecasts of ash trajectory and concentration. Graphical forecasts are an integral part of VAAC Montreal's products and services.