Weather tracker: lake-effect snow blankets parts of north-east US

There was significant snowfall in five states downwind of the Great Lakes, including 4ft in western New York state

As meteorological autumn drew to a close at the end of last week, parts of the north-east of the US saw substantial snowfall thanks to a phenomenon known as lake-effect snow".

This occurs when cold air passes over relatively warm lake waters, causing the layer of air near to the surface to absorb heat and moisture. Warmer than the air above it, this layer of air then starts to rise, cooling and condensing into clouds that deposit snow on the windward side of the lakes in extremely localised bands.