Snow Tornado: A Rare Hybrid of Atmospheric Mechanics
The term "snow tornado" is not an official meteorological definition, but describes a series of extremely rare and impressive phenomena in which a rotating column of air interacts with snow. Unlike classic tornadoes associated with powerful convective thunderstorm clouds (supercells), snow whirls form under different conditions and have a different physical nature. They can be classified into two main types.
1. Winter Tornadoes – True Tornadoes in Snowy Weather
This is the rarest and most dangerous phenomenon. It represents a true tornado (vortex, originating from cumulonimbus clouds and touching the ground) that occurs in winter conditions, often at temperatures around freezing or even below.
Formation Conditions: A powerful atmospheric front carrying unstable air is required. Winter instability occurs rarely, but it is possible when warm, moist air from the ocean (for example, from the Gulf of Mexico in the USA) collides with cold continental air. Rising currents in the front area form thunderstorm clouds capable of producing tornadoes. Snow or freezing rain may fall in the rear, cold part of the system, creating a paradoxical picture.
Examples:
Tornado outbreak on January 24, 1967, in the state of Wisconsin (USA). During a severe blizzard and snowstorm, several tornadoes were recorded. One of them, category F4, traveled 43 km, killing 3 and injuring 50 people, destroying homes and farms under the snow cover. This is one of the deadliest "snow" tornadoes in history.
Tornado in the UK on November 23, 1981, accompanied by snowfall and hail.
Characteristics: Such tornadoes are especially dangerous due to poor visibility (snowfall or blizzard masks the funnel) and unexpectedness (people are not prepared for tornadoes in winter).
2. Snow Whirls Similar to Tornadoes (Snow Devils / Snow Spouts)
This is not a tornado in the strict sense. They form not from clouds, but from the surface of the earth and by a mechanism clo ...
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