The fog of 12/13 August 2025 – empirical forecasting considerations

Slack pressure gradients in summer may be associated with sunny warm weather, promoting temperatures above the normal – especially in areas away from the sea. However, in warm‐sector weather, the air is moist and condensation may occur over comparatively cool seas, fog perhaps drifting on shore, or the chance of inland fog by night. This case illustrates the many factors that must be taken into consideration when trying to forecast the formation and advection of sea fog, as well as the effect of cooling inland. Forecasters can add value to numerical output, using experience and observed data.