Module 03: Cloud & storm-structure identification

Before you can tell two features apart you have to be able to name them. This is the vocabulary the other ten lessons are written in. (20 min)

Overshooting top, backsheared anvil, striations, flanking line, mammatus. Four of those tell you about the updraft. One of them tells you nothing, and is the most misreported cloud in the sky. (25 min)

Two regions under a storm, doing opposite things. Getting the boundary between them right is what makes every later lesson possible. (25 min)

Air being pulled into a storm makes clouds of its own, and two of them are long, low and sinister-looking from the wrong angle. (20 min)

The cold air a storm makes has to go somewhere, and on its way out it builds the most dramatic and most misreported clouds in severe weather. (25 min)

Two lowerings. One is the storm breathing out and one is the storm breathing in. Everything about how you report them is different, and this is the call spotters get wrong more than any other. (30 min)

There is a bright line between a funnel cloud and a tornado, it is written down, and it is not about how the thing looks. (25 min)

Not every spinning thing under a storm is a tornado, not every tornado comes from a mesocyclone, and the boundary between those two statements is genuinely disputed. (25 min)

The same storm type in three costumes. One of them shows you everything, one shows you enough, and one shows you nothing while doing everything. (30 min)

A line of storms gives you a shelf cloud, a lot of wind, and almost none of the visual vocabulary the rest of this module just taught you. (25 min)

Everything you have learned to identify can be made unrecognizable by the angle you are standing at, the light behind it, or the ten miles between you and it. (20 min)