As temperatures warm with the arrival of the summer months, flooding is also likely to occur more frequently due to the higher amount of moisture in the air. You’re also more likely to see an alert pop up for something called “areal flooding.” Here’s what that means.

An areal flood watch is specifically issued when there is a threat of widespread flooding that is expected to develop gradually, usually from prolonged and persistent moderate to heavy rain.

(MORE: Flash flood emergency: 3 things to know about this rare alert that signals Imminent Danger)

It makes sense that this type of flooding is more likely in the warmer months, because many areas start to see what feels like endless rounds of rainfall from weather patterns that seem almost stuck. This causes ponding in low-lying and flood-prone areas as well as a gradual increase in water levels in creeks and streams.

The timing is the biggest difference between areal flooding and flash flooding, which usually happens within six hours after rainfall has ended as water is funneled into waterways that then overflow.

(MORE: Flood safety: what to do before, during and after a flood)

It’s worth noting that even though flash flooding happens quickly and is more likely to catch people off guard, areal flooding can still be a threat to both your safety and your property and needs to be taken seriously.

Sara Tonks is a content meteorologist with weather.com and has a bachelor’s and a master’s degree from Georgia Tech in Earth and Atmospheric Sciences along with a master’s degree from Unity Environmental University in Marine Science.