The Shallow Convective Zone – enhanced gusts in operational UKV forecasts of developing mid latitude windstorms.

Intense extratropical cyclones contain a range of mesoscale features capable of producing hazardous surface wind gusts. Well‑established examples include the cold conveyor belt, the evocatively named sting jet, and lines of locally enhanced convection along narrow cold frontal zones. These features are now routinely represented in convection‑permitting numerical weather prediction models, whose horizontal resolution approaches kilometre scale, and have been extensively studied using both idealised simulations and case‑study analyses.

While such models are commonly used in research to investigate storm structure and underlying physical mechanisms, operational meteorologists are uniquely placed to identify emerging or poorly documented features through continual real‑time interrogation of high‑resolution forecasts. In this study, a previously under‑recognised wind‑producing feature is identified within operational forecasts from the UKV, the Met Office’s kilometre‑scale limited area model, during Shapiro–Keyser type extratropical cyclones.

This feature occurs within a region of the cyclone traditionally considered to be of relatively low wind hazard, and is therefore not typically a focus of operational attention. Enhanced surface gusts associated with this feature may come as a surprise, particularly as it is not well represented in coarser‑resolution global models. As a result, there is potential for mistimed wind warnings and insufficient preparedness if reliance is placed solely on conceptual models or lower‑resolution guidance. Evidence for the existence of this feature is supported by surface and near‑surface observations during recent high‑impact windstorms.

The identification of this feature, together with subsequent investigation of its dynamical mechanisms, frequency of occurrence and predictability, has clear potential to improve the timing and targeting of wind warnings for future storms. More broadly, this work highlights the value of operational experience in complementing research‑driven model analysis and advancing understanding of high‑impact weather.