CIN and stable layers in the pre-convective environment

In convection permitting models there is a bias towards earlier convection initiation, and a problem with the generation of small showers which are not seen in observations. A possible cause for this is the misrepresentation of the pre-convective environment, with insufficient convective inhibition (CIN) and stable layers in the models. To assess this systematically we compare three years of radiosonde ascents from 14 sites in and around Britain to profiles taken from the UK Met Office UM analysis and forecasts for both the global and limited area configurations. This comparison shows that larger values of CIN are underrepresented in model analyses, but that this problem is reduced in forecasts. When considering stable layers as defined by high values of the vertical gradient of virtual potential temperature it is also found that stable layers observed by radiosondes are more likely to be deeper than those identified in model profiles. These statistical results are put into context by considering the evolution of case studies from the 2023 Wessex Convection (WesCon) field campaign. For these cases a higher spatial and temporal density of radiosonde launches allows us to illustrate the impacts of the misrepresentation of atmospheric stability on the representation of convection in the model.