How did so much snow fall on Buffalo on Tuesday?

Thursday, November 20, 2014, 4:19 PM - With parts of Buffalo buried under at least 160 centimetres of snow in just one day, exactly what combination of wind, water and bad luck aligned to deliver this incredible, and deadly, amount of snowfall? Read on to find out.

Buffalo is no stranger to snow, of course, and there are a few good reasons for this.

• First of all, the city in a region that frequently sees large storms sweep through during the colder months of the year, so it sees the same snow everyone else in the area gets.
• Secondly, it's located in the vicinity of two freshwater lakes that rank among the largest in the world - Lake Erie and Lake Ontario - so, with the right conditions of cold air and warm water, winds blowing off of either lake can carry intense bands of snow across the city.
• Third, it's exact location - right on the eastern tip of Lake Erie - plays a fairly large role in the city getting some really extreme lake effect snowfall at times, which will be discussed further below.

Lake-effect snow squalls need a few factors to get them going - cold winds that are fairly-well lined up with each other with height, blowing over open water that has a surface temperature at least 13 degrees C warmer than the air 1,500 metres above it. That gives enough evaporation from the lake's surface to produce the instability for clouds to form and eventually produce precipitation that will freeze into snowflakes in the cold air. At the same time, it provides the right push from the winds to keep the clouds rolling along over more open lake surface to gather more moisture and keep them moving along after they reach land (and thus lose their connection to the moisture supply). The last piece of the puzzle falls into place when the 'fetch' - the amount of open lake water the winds have to blow over before they reach land again - which needs to be at least 100 kilometres long.

 RELATED: Record-breaking snow covers Buffalo

This is true for any instance of lake effect snow, but these squalls don't always deliver the 'snowpocalypse' conditions that Buffalo saw on Tuesday. So, what happened?

The requirements for lake effect snow were definitely met for the day.

Lake temperatures across the entire surface ranged from around 5-12 degrees C above zero, as shown in the map above. Meanwhile, about a kilometre and a half above the lake, air temperatures were down around -18 to -20 degrees C. This big temperature difference, especially near the eastern end of the lake, definitely provided enough fuel for lake effect snow to develop.

However, what was really behind this event, literally, was that the wind direction was lined up perfectly, with a fetch that extended nearly the entire length of Lake Erie - roughly 350 km of open water straight from Sandusky to Buffalo - three and a half times the minimum distance required just for the squalls to get started.

So, with access to the maximum amount of uninterrupted lake surface, this produced the absolute best conditions for the squalls to form, which translated into the absolute worst conditions for the people in and around the city of Buffalo.

That wasn't the end of the snow, either. While the winds have shifted, cutting off the fetch needed to form more squalls off the eastern end of Lake Erie, one of those 'large storms' is sweeping through the area, affecting most of southwestern and central Ontario tonight (along with the Buffalo area as well).

Weather Network Forecast Radar for Nov 19, 2014, at 5 pm EST

Check out your local forecast, both on TV and on the web, to see what you could be in for from this new system.

 WINTER OUTLOOK: We're unveiling our preview of the coming season on Monday at 9 p.m. Eastern. Tune in to The Weather Network on TV!