An extreme example is when an entire storm system becomes a mesocyclone
youtube.com/embed/CB-Prsvd10EWhat is a supercell?Supercells are caused, unlike other storms, by a rotating updraught, also called a mesocyclone
It develops much like the multicell line, except that the balance of wind forces produce a pressure deficit inside the storm, known as a mesocyclone
. This mesocyclone
is weak at first and measures several miles in diameter.
Nonetheless, the occurrence of cyclic tornadic storms, those that produce tornadoes during almost every mesocyclone
cycle [4, 6, 12-16], implies the continual presence of conditions favorable for repeated tornadogenesis.
Any rotation, known as a "mesocyclone
," detected by the Doppler component of the radar, is also a good indication of a strong, hail-producing storm.
: This rotating column of air within the core of a supercell needs both updrafts and downdrafts to form.
The strongest tornadoes often develop with storms that have a large area of strong wind rotation -- called a mesocyclone
-- within the storm cloud.
FUNNEL CLOUD: An updraft of rising warm air pushes the rotating column of air into a vertical column, or mesocyclone
. As the updraft cools, water vapor within intensifies the storm clouds.
Scientists know what forms a mesocyclone
, but they are largely lost when it comes to understanding which ones will spawn tornadoes and how violent they will be.
Scientists involved in the research have shown that the spontaneous formation of a "volcanic mesocyclone
" - a rotating, column-shaped vortex - causes the volcanic plume to rotate on its axis.
"What's not well understood is how the mesocyclone
then spawns a tornado," says Wurman.