Mesohigh and gust front

  • the downdraft also can produce two other features associated with a storm....
  • mesohigh - an area of high pressure at the surface created by the cold heavy pool of air associated with the downdraft
  • gust front - the leading edge of the cold air associated with the downdraft
  • gust front passage is noted by:
    • calm winds
    • then gusty winds and a temp drop
    • then precip
  • the gust front is a convergence region between the cool outflow and the warm, moist inflow
  • hence, the gust front is able to force the warm, moist air upward, generating a new cell
  • if a storm continuously regenerates in this manner, it is called a multi-cell storm.  Find the different cells in this picture.
  • shelf (arcus) and roll clouds are often associated with gust fronts

image adopted from Meteorology Today by C. Donald Ahrens  1994 West Publishing Company