Upslope Fog

  • As the parcel ascends up the slope, it expands and cools to the dew point

  • Upslope fog/clouds then form

  • Need winds to move air up the slope

  • Need a slope!

  • data example:    

QUESTIONS FOR THOUGHT:

1.  On each of three different days over the Gulf of Mexico, the air has the following temperature and dew point:

  1. T=40 ºC, Td=5 ºC
  2. T=40 ºC, Td=35 ºC
  3. T=10 ºC, Td=-5 ºC

On which days will upslope fog form at Denver, CO? Show work.

2.  If evaporation of water vapor from the ground to low levels in the atmosphere occurs at a rate such that the dew point temperature of a parcel of air increases by .2 ºC per hour and it takes 1.5 days for a parcel with T=25 ºC and Td=0 ºC to travel from Illinois (elevation=1000') to Denver (elevation=5280'), will fog form in Denver? Show work.