<p>Tornadoes, land/waterspouts and supercell thunderstorm mesocyclones are examples of vortices where Coriolis is unimportant.  Tornadoes are in cyclostrophic balance.  Land and waterspouts (as well as non-supercell tornadoes) arise from horizontal convergence of vertical vorticity.  The supercell mesocyclone spin originates as horizontal vorticity that is tilted and stretched into vertical vorticity.  These vorticies can spin in either direction in either hemisphere.  </p>

CC BY-SA 3.0
2015-03-23T19:43:27.743Z
2015-03-23T19:43:27.743Z
casey
<p>In a cyclone, the pressure gradient force (PGF) and the Coriolis force sustain the spinning motion and causes the direction of spin (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere). Are there vortices in the atmosphere which are sustained only by the pressure gradient force?</p>

<meteorology><vorticity><cyclone>
Vortices in the Atmosphere Sustained only by PGF
user4624937
# Vortices in the Atmosphere Sustained only by PGF

(Asked by: username_0 on 2015-03-23)

In a cyclone, the pressure gradient force (PGF) and the Coriolis force sustain the spinning motion and causes the direction of spin (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere). Are there vortices in the atmosphere which are sustained only by the pressure gradient force?

**Tags:** meteorology, vorticity, cyclone


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## 1 answers

### Answer by username_1 on 2015-03-23. Score: 9 | Accepted answer

Tornadoes, land/waterspouts and supercell thunderstorm mesocyclones are examples of vortices where Coriolis is unimportant. Tornadoes are in cyclostrophic balance. Land and waterspouts (as well as non-supercell tornadoes) arise from horizontal convergence of vertical vorticity. The supercell mesocyclone spin originates as horizontal vorticity that is tilted and stretched into vertical vorticity. These vorticies can spin in either direction in either hemisphere.


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