At a station at the surface, when will significant weather with a warm front occur?

Significant weather associated with a warm front typically occurs predominantly before the front actually passes through a location. As the warm, moist air advances and rises over the colder air ahead of the warm front, it cools and condenses, leading to cloud formation and often precipitation. This process can result in extensive cloud cover, rain, or even thunderstorms before the front reaches any given point.

The warm front itself is characterized by a gradual rise in temperature and humidity as the warm air replaces the colder air, which can also lead to the development of widespread stratiform clouds. As the warm front approaches, weather conditions often deteriorate, with increasing cloudiness and precipitation starting well before the front's actual passage.

Once the warm front passes, conditions typically improve as the warm air settles in, and this results in a shift to clearer skies, marking the end of significant weather events typically associated with that front. Thus, the occurrence of significant weather with a warm front is mainly observed prior to its passage, as the lifting action of the advancing warm air generates the associated meteorological phenomena.