Exploring spatio-temporal distributions of MTG-FCI TCWV fields in pre-convective environments

Low-level moisture is a key ingredient for convective initiation and deep, convective development. Monitoring and characterizing its spatial distribution and temporal evolution are essential for improving nowcasting of deep convection and associated high-impact weather. We explore the capabilities of the newly developed total column water vapor (TCWV) product from the Meteosat Third Generation (MTG) Flexible Combined Imager (FCI) for the assessment of pre-convective environments.

The Near-Infrared (NIR)-based TCWV retrieval algorithm uses the measurement ratio of the water vapor absorption band at around 0.914 micron and a nearby window band, offering high temporal (10 min) and spatial (sub-satellite point 1km) resolution. While TCWV represents the full atmospheric column, the NIR method is particularly sensitive to near-surface variability in moisture content. This enables the detection of moisture changes in the boundary layer potentially associated with pre-convective and convective initiation conditions before the onset of clouds and precipitation.

Our analysis will focus on spring and summer months across Europe, targeting regions with mainly clear-sky conditions preceding convective development on local to regional scales. Preliminary results show that FCI TCWV is able to resolve small-scale water vapor features in the boundary layer and ongoing validation studies with reference TCWV datasets support the robustness of the retrievals.