Climatological Tracking and Lifecycle Characteristics of Mesoscale Convective Systems in Northwestern South America.

Mesoscale convective systems (MCSs) are crucial in shaping large‐scale tropical circulation and the hydrological cycle, particularly in Northwestern South America (NwSA), a region marked by complex terrain and significant MCS activity. Understanding MCSs in NwSA is vital due to their impact on precipitation patterns and potential for severe weather events. To enhance this understanding, the ATRACKCS algorithm was developed for tracking convective systems, utilizing precipitation and brightness temperature data sets. This research focuses on documenting the spatiotemporal variability of MCS occurrence, life cycle, and movement. Notably, MCS hotspots were identified to the west of the major orographic features in the region, with maximum occurrences at night, contrasting with the region's typical afternoon peak in land convection. MCS movement is also heavily influenced by topography, with higher velocities on the eastern (windward) side of the Andes compared to velocities on the western (leeward) side. MCSs generally move westward, driven by easterly winds, but this pattern is not consistent throughout the year or region. Northward movement is predominant to the west of the Andes, while southward movement is observed to the east. These seasonal and regional movement variations are linked to factors such as the intertropical convergence zone position, moisture availability, topography, and low‐level jets. This research underscores the complexity of MCSs in NwSA and emphasizes the need for detailed studies on the atmospheric environment shaping these systems. Additionally, it provides a robust 21‐year MCS database for NwSA and an advanced tracking tool for research in various geographic contexts and impact areas. Plain Language Summary: Extreme storms are linked to large clusters of clouds called Mesoscale Convective Systems (MCSs). Understanding MCSs is important because they produce rainfall and severe weather. Northwestern South America (NwSA) has many MCSs but studying them is difficult due to complex terrain and limited radar data. Here, we developed a new algorithm (ATRACKCS) to study MCSs over NwSA using satellite data, including their occurrence, duration, and movement. Topography has a strong effect on MCS. They occur more on the west side of the Andes mountain but are faster on the east side than to the west. Also, MCSs tend to move westward and are affected by winds, but this movement varies throughout the year and region. This variability could be explained by moisture availability, low‐level jets, and topography. This research shows how complex MCSs are in NwSA and highlights the need for detailed studies on the environmental conditions affecting them. It also helps us to better understand these storms by providing a robust database and a valuable tool for studying them in other places worldwide. Key Points: A climatological analysis of mesoscale convective system (MCS) characteristics as occurrence, life cycle and propagation are presented for Northwestern South AmericaContinental MCS hotspots are predominantly nocturnal and located west of topographic featuresMCS move mostly westward. However, their movement doesn't align with ambient winds at certain locations and times of the year [ABSTRACT FROM AUTHOR]