3. Stability

Changing Stability » Advection Uniform Advection

In the case of uniform advection, an air mass with a different lapse rate may move into the forecast area. The most obvious example of this phenomenon is frontal passage. It's generally safe to assume that the imported air mass will have the typical weather associated with the imported lapse rate.

This sequence of soundings comes from a location along the California coast and spans the passage of a landfalling cold front. Looking at the lower levels over the period, we see a stable, moist, prefrontal air mass replaced by a less stable, drier, postfrontal airmass.