Decreasing pressure foretells rainy, windy, stormy weather.

Small, quick drops in pressure are good indicators that short periods of wind and rain will follow.

Slow, moderate drops in pressure indicate a low pressure system is in the area but this will not likely cause severe weather.

Slowly decreasing pressure over a longer period of time foreshadows poor weather that will last for some time.

Slowly decreasing pressure that was preceded by high pressure means that poor weather will be particularly bad.

Increasing pressure is an indication of dry, colder weather.

Slow, large rises in pressure mean that good weather is approaching and will likely last a long time.

Rapidly rising pressure when the pressure is already low is a good indicator of upcoming fair weather.

Rapidly decreasing pressure is a good prediction that a storm will hit within six hours.