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This movement of large volumes of air, especially when regions of hot, wet air rise, can create large clouds, and is the central source of thunderstorms. Drafts can also be caused by low or high pressure regions. A low pressure region will attract air from the surrounding area, which will move towards the center and then rise, creating an updraft.
The formation of multicellular thunderstorms imply that the updraft in the mother thunderstorm is offset from its downdraft. New cells usually form in the upwind (usually western or southwestern) part of the storm where the downdrafts of the mature cells meet the environmental wind, lifting air parcels and triggering new convection.
With buoyancy rapid within the lower and mid-levels of a mature thunderstorm, updraft and downdraft create distinct mesocenters of pressure. As thunderstorms organized in squall lines, the northern end of the squall line is commonly referred to as the cyclonic end, with the southern side rotating anticyclonically (in Northern hemisphere).
Figure 1 : Forward area of a severe cumulonimbus moving to the west.This area is precipitation-free and the site of widespread updrafts. The updrafts under a cumulonimbus can be extremely laminar, extensive, and uniform, this is particularly true during the buildup of the thunderstorm. [8]
The resulting thunderstorms are “very dangerous” for air travel, Struckmann said. This is due to the “severe turbulence caused by updrafts, downdrafts, winds and hail.”
For tornadoes to form, we need thunderstorms, which have very strong updrafts and downdrafts, said Bill Gallus, a professor in the department of Geological and atmospheric sciences at Iowa State ...
Rear-flank downdrafts have a well-established association with hook echoes. [3] [4] Firstly, the initial rear flank downdraft is air from aloft transported down to the surface by colliding and mixing with the storm. [2] Secondly, hook echoes form through advection of precipitation from the rear of the main echo around the region of strong ...
One can distinguish three stages in the evolution of a thunderstorm cell: [2] [3] formation: the upward current of the cell intensifies and allows the condensation of water vapor from the rising air parcel. This forms a cumulus congestus, then a cumulonimbus when ice crystals form at its apex which spreads horizontally in contact with the ...