Precipitation in the clouds is usually formed below 20,000 feet, as sketched in the first diagram on the right. Upward and downward motions in ordinary snowstorms are rather gentle. The exception is lake-effect snow, where the clouds are created by heating of air moving over relatively warm lakes. Lake-effect snowstorms have narrow clouds shaped more like ordinary thunderstorms, and actually sometimes develop thunder and lightning. Most thundersnow events develop when ordinary flat, layered snow clouds develop upward bumps or turrets, as illustrated in the second diagram.
https://weather.com/science/news/what-thundersnow-and-why-does-it-happen-20140218
Thundersnow is a snowstorm event in which thunder and lightning occur. An example is the classic 2011 thundersnow in Chicago that surprised Jim Cantore. Thunderstorms accompanied by snow are usually of a different character than the normal thunderstorm.
https://weather.com/science/news/what-thundersnow-and-why-does-it-happen-20140218
Heat lightning is a term used to describe lightning flashes that are too far away from you to hear the thunder. The reason that it is called heat lightning is that it appears most often on a hot summer day when the sky is clear overhead.
http://www.weatherwizkids.com/weather-lightning.htm
To judge how close lightning is, count the seconds between the flash and the thunderclap. 1  Each second represents about 300m (984.25ft). 2  Thunder is not only heard during thunderstorms. It is uncommon, but not rare, to hear thunder when it is snowing. 3  Lightning does not always create thunder.
http://www.loc.gov/rr/scitech/mysteries/thunder.html
Thunder is caused by lightning. When a lightning bolt travels from the cloud to the ground it actually opens up a little hole in the air, called a channel. Once then light is gone the air collapses back in and creates a sound wave that we hear as thunder.
http://www.weatherwizkids.com/weather-lightning.htm
Thunder Fun Facts: 1  To judge how close lightning is, count the seconds between the flash and the thunderclap. Each second represents about 300m (984.25ft). 2  Thunder is not only heard during thunderstorms. It is uncommon, but not rare, to hear thunder when it is snowing. 3  Lightning does not always create thunder.
http://www.loc.gov/rr/scitech/mysteries/thunder.html
Thunder Experiment: This experiment allows kids to make thunder, in a way that allows them to understand how it is made by lightning. Thunderstorm Experiment: Here is a great way to teach kids how to track a thunderstorm.
http://www.weatherwizkids.com/weather-lightning.htm
Next time you see a storm, count the number of seconds between when you see the lightning and hear the thunder. Take the number of seconds and divide by 5 and that will tell you how far away the storm is in miles. For example: If you counted 10 seconds between the lightning and the thunder, the lightning is 2 miles away! Know the Lingo SEVERE THUNDERSTORM WATCH - A severe thunderstorm (damaging winds of 58 miles per hour or more, or 1 hail in diameter or greater) is likely to develop in your area.
http://www.weatherwizkids.com/weather-lightning.htm
Thunder is caused by the rapid expansion of the air surrounding the path of a lightning bolt. Federal Emergency Management Agency (FEMA): Thunderstorms and Lightning - Facts about lightning and thunderstorms are presented, as well as information on protecting oneself during lightning and thunderstorms.
http://www.loc.gov/rr/scitech/mysteries/thunder.html
Lightning is a bright flash of electricity produced by a thunderstorm. All thunderstorms produce lightning and are very dangerous. If you hear the sound of thunder, then you are in danger from lightning. Lightning kills and injures more people each year than hurricanes or tornadoes; between 75 to 100 people. What causes lightning?
http://www.weatherwizkids.com/weather-lightning.htm
what is the thunder
Thunder is caused by the rapid expansion of the air surrounding the path of a lightning bolt.