What are the weather conditions associated with a depression?

A depression is when a wedge of warmer air forces its way into a larger body of cold air. This leads to several distinctive weather patterns. Where the warm air meets the cold air, a front is formed. Warm air is less dense than cold air, so the cold air undercuts the warmer air at the warm front. This forces the warm air to rise upwards. As it rises, the water vapour in the air condenses as it becomes cooler, which means that clouds are formed. These are usually nimbostratus clouds, so rainfall may be experienced at the warm front. Within the warm wedge of air, the weather conditions are warmer and there may be intermittent showers. Then, at the cold front, cold air once again undercuts the warmer air, leading to rapidly rising air. This can lead to the formation of tall clouds as the air rapidly rises upwards, such as cumulonimbus clouds, which can be the cause of heavy rain and even thunderstorms. (This concept is best explained with a diagram so use of the whiteboard would be helpful for this answer).