Gap Winds

Gap Winds

After completing this lesson, the learner should be able to do the following:

With regard to the description of gap winds:

  • Recall where in a gap the strongest wind speeds are typically observed.
  • Describe the different kinds of topographic gaps and their effect on gap flow.
  • List at least 3 natural hazards that may be associated with gap winds.

With regard to the structure of gap winds:

  • Describe how wind speed varies through the gap during a gap flow event.
  • Describe the temperature profile through a gap during a gap flow event.
  • Describe the pressure profile through a gap during a gap flow event.

With regard to the origin of gap flows:

  • Describe the conditions required for geostrophic flow.
  • Recall that gap winds are typically non-geostrophic.
  • Describe the origin of the pressure gradients that occur across gaps.
  • Recall that the thinning of low-level cool air at a gap exit can increase the pressure gradient across a gap.
  • Recall that adiabatic warming of downslope winds can increase the pressure gradient across a gap.

With regard to forecasting gap winds:

  • Qualitatively describe how varying the following factors affects wind speed through a gap:
    • Pressure gradient
    • Surface roughness
    • Gap length
    • Temperature
  • Describe the horizontal resolution of a mesoscale model required to accurately forecast flow through a gap.