A Single-Column Method to Identify Sea and Land Breezes in Mesoscale-Resolving NWP Models

Abstract One of the most prominent mesoscale phenomena in coastal zone is sea-breeze/land-breeze circulation. The pattern and its implications for weather areas are well described, with mesoscale-resolving operational NWP models circulation can be captured. In this study, a straightforward method to identify sea land breezes based on change wind direction column above grid point coastline presented. was tested southern Sweden using archived output from HARMONIE-AROME model promising results, describing both seasonal diurnal cycles well. complex coastline, such as narrow straits, concept land–sea breeze becomes less clear, several ways address problem suggested discussed. With an index breezes, forecaster better understand express situation add value people zone. Further, indices used study systematic biases create climatologies breezes. Significance Statement A that frequently occurring circulation, purpose test new automatically forecasts. Knowing if or helpful understanding situation. It also behavior, example, errors forecast temperature during sea-breeze conditions. has been seven sites shows results case studies multiyear statistics.