A low pressure system allows clouds to form. It this case you can get a cloudy day, you can also get rain too.
The low pressure system will bring warm and rainy weather to Chicago.
low pressure
Strong winds and precipitation.
A Low Pressure System is the kind of system that allows clouds to form. When clouds form, you can get a cloudy day, with most low pressure systems, the clouds bring the rain.
Areas of high pressure typically bring clear skies, calm weather, and light winds. In contrast, areas of low pressure usually result in unsettled weather, including clouds, precipitation, and stronger winds.
Stormy weather often occurs along the boundary between air masses or in association with a low pressure system.
A decrease in air pressure usually indicates an approaching low-pressure system, which is often associated with unsettled weather such as rain, storms, or strong winds.
High Pressure, in this case we are talking about a High Pressure System. A High Pressure System doesn't allow clouds to form, which means you can get great weather from this type of system.
Low pressure systems contain a lot of moisture. These systems usually bring stormy wet weather. There are typically a lot of clouds with a low pressure system.
A system associated with weather conditions like lots of clouds, thunderstorms, and the possibility of tornadoes is typically a low-pressure system or a cyclone. In the United States, this kind of weather pattern is often seen with severe thunderstorms forming in association with a cold front. These conditions can also lead to the development of supercell thunderstorms that are capable of producing tornadoes.
In a high pressure area, good warm weather will occur. In a low pressure area, colder rainy weather will occur.
Pressure, on it's own, does not indicate any particular weather. It is the changes in air pressure, along with other factors such as humidity etc which indicates the proposed weather changes.