Description

Thundersnow, is an unusual kind of thunderstorm with snow falling as the primary precipitation instead of rain. It typically can occur within the cold sector of an extratropical cyclone or in mesoscale bands not associated with such a cyclone. Thermodynamically, it is no different than any other type of thunderstorm, but the top of the cumulonimbus cloud is usually quite low. In addition to snow, hail may fall as well. Overall, these storms are not as strong as in spring or summer when temperatures are warmer and the air is more unstable.

Lake effect snow

Lake effect thundersnow occurs after a cold front or shortwave trough aloft passes over a body of water. The relatively warm water heats the air near the surface and with cold air aloft, steep lapse rates mean convective development is possible. See the separate article on Lake Effect Snow for more detailed information.