Updated: May 1, 2019
When thunderstorms develop and evolve, their "exhaust" is cold dense air flowing down through the storm, striking the ground and moving outward away from the storm. To better understand this, imagine pouring pancake batter onto a griddle. The edge of that pancake is the outflow boundary which is essentially a gust front of sorts. Are they dangerous if you encountered one of these in flight? More details on these convective outflow boundaries can be found in the AvWxWorkshops.com library of workshops here. Members can also view this workshop in the new WeatherSpork app. Enjoy this loop of a nearly perfect outflow boundary emanating from convection that erupted over the Fort Worth WSR-88D Doppler radar site. If you were wondering, these outflow boundaries (and gust fronts) are filtered out of the radar depiction you will get with SiriusXM and ADS-B.
Most pilots are weatherwise, but some are otherwise™
Weather Systems Engineer
CFI & former NWS research meteorologist