On Monday afternoon, a microbust, or supercell thunderstorm, hit south Tempe. Over the next hour, it quickly traveled north throughout the Phoenix metro area and strengthened, bringing intense rain, ...

In about 15 minutes, Tempe recorded nearly three-quarters of an inch of rain. A supercell thunderstorm forms when wind speed and direction change with height, a phenomenon called wind shear.

Not all thunderstorms can produce tornadoes - only about 30% of supercell thunderstorms actually spawn these rotating columns of air. Supercells are severe thunderstorms with intense, rotating ...