A pulse storm is a single cell thunderstorm that is usually not very strong and, if does so, only produces severe weather for short periods of time, weaken, then produce in another short burst, hence "pulses". They will usually form in environments with small vertical wind shear and on average do not last very long. Severe weather in a pulse storm will most often occur during a momentarily strong updraft and take the form of hail or particularly damaging winds from downbursts. On a rare occurrence there could be a weak tornado from a pulse storm.
