Large‐scale cloud, precipitation, and upper level features during Fronts and Atlantic Storm Track Experiment as inferred from TIROS‐N Operational Vertical Sounder observations

Physical parameters retrieved from the measurements of the TIROS‐N Operational Vertical Sounder aboard the National Oceanic and Atmospheric Administration satellites are used to study the large‐scale cloud, precipitation, upper level features during the Fronts and Atlantic Storm Track Experiment period: the cloud top pressure, a precipitation index, and the temperature of lower stratosphere (TLS), respectively. The three dynamically consistent (i.e., temporally and spatially collocated) retrievals are able to characterize the weather regimes through their organization in locations expected from the cyclonic activity. Moreover, high‐level cloud patterns, when accompanied by rain, can be discriminated with respect to TLS field. When no (or weak) warm TLS feature can be found upstream, such patterns are frontal systems. On the contrary, a warm TLS event present upstream of a rainy cloud feature suggests a baroclinic interaction. In this case, the high‐level cloud pattern is associated with a large‐scale baroclinic cyclone, or at least a mature low. When examining the most precipitating cases using a composite technique, the nondeveloped systems (in term of absence of high‐cloud cover) are characterized by the absence of warm TLS features, grouping mostly blocking‐regime cases. On the other hand, the cases that are well developed in terms of cloud cover are characterized by warm TLS patterns upstream the precipitation area. Moreover, the well‐developed cases could be grouped into three families depending on the orientation of the warm TLS features: zonal, anticyclonic, and cyclonic. Only the later family, characterized by a cyclonically tilted trough, clusters the large‐scale baroclinic systems that all occurred during the zonal regime. This suggests that a cyclonically tilted trough has a positive impact on the development of cyclones.