Gust fronts are usually accompanied by a sharp drop in temperature and increase in wind speed (and/or wind shift). Winds gusted to 44 miles per hour at the Spaghetti Bowl with the passage this evening.
Thunderstorm outflow is an example of a gravity current in which cold, dense air spreads and displaces warmer, less dense air. There is usually a pronounced nose at the leading edge of the gravity current.
Gravity currents are common in all sorts of "geophysical fluids", including the powder avalanche. The classic textbook on the subject is Gravity Currents by John Simpson.