Backsheared anvil – updraft strength vs. wind shear

  • 10 months ago
  • 0
  • Author: SW101


The shape of the thunderstorm’s anvil depends on the strength of the updraft and strength of the upper level winds. Strong upper level winds are typical for strongly sheared environments. An anvil that forms in strong upper level winds becomes elongated, extended downwind .

  • In environments with little or no wind shear, the anvil spreads evenly in all directions. As seen from above (satellite) the anvil will be generally symmetric, circular.
  • In environments with moderate shear the anvil will be elongated into a more elliptical (oval) shape.
  • In environments with strong to very strong shear, the anvil will have a U- or V-shape, elongated far downwind.
  • The forward extent of a backsheared anvil depends on the strength of the updraft relative to upper level winds: the stronger the updraft, the larger the forward extent.