The primary concern for the Southwest lies in the potential for significant rainfall across Arizona and New Mexico. This region has already experienced an unusually wet September, leaving the ground saturated and more susceptible to rapid runoff. If Rachel's moisture reaches these states, it could trigger renewed flooding, dangerous mudslides, and debris flows, particularly in burn scar areas or regions prone to such events. The combination of existing wet conditions and an influx of tropical moisture poses a serious threat to residents, infrastructure, and ecosystems in these areas. Coastal communities in California and Mexico are also at risk from the elevated surf, increasing the potential for coastal erosion and hazardous conditions for beachgoers and maritime activities.