When thunderstorms form in wintry conditions they can sometimes give rise to heavy downpours of snow which are often called ‘thundersnow’.Thundersnow is unusual only because it can only occur in a few months of the year. What does thundersnow look like? When thundersnow occurs at night the lightning appears brighter – this is because the light reflects off the snowflakes. Interestingly, the snow contained within the thunderstorm acts to dampen the sound of the thunder. While the thunder from a typical thunderstorm might be heard many miles away, the thunder during a thundersnow event will only be heard if you are within 2 to 3 miles of the lightning.