Outflow Boundary

Learn how do haboobs form when thunderstorm microbursts generate cold pool outflows that lift dry sand into massive, rolling walls of dust.

Learn how do gustnadoes form along thunderstorm outflow boundaries through horizontal wind shear and vertical rotation. Compare them to true tornadoes.

Learn how mesoscale convective system formation occurs as storm cells merge along outflow boundaries to create severe weather complexes.

Learn how squall line formation occurs when wind shear and cold pools interact to create destructive linear storms. Discover how these systems work.

Learn how multicell thunderstorm formation works via gust fronts and vertical wind shear. See how these regenerative storm clusters stay active for hours.

Learn how do arcus clouds form when thunderstorm outflow lifts warm air along a gust front. View the science behind shelf and roll cloud development.

Learn how roll cloud formation works when cool air lifts warm moist air along a gust front. Explore the science behind these detached tube clouds.

Shelf cloud formation happens when rain-cooled air lifts warm air along a gust front. Learn how these low arcus clouds mark the edge of a storm.

Understand how mesoscale convective systems form organized storm clusters across Australia and lead to severe weather hazards like squall lines.

Learn how squall lines Australia form and how to identify damaging straight-line winds on radar to stay safe during severe weather.

Learn about the five types of severe thunderstorms in Australia and how the BOM classifies supercells, squall lines and clusters to help you find out.

Our guide explains the nature of a shelf cloud, how it forms on a gust front, and why it signals a weather change.