The primary risk for Arizona is flash flooding, particularly in washes, low-water crossings, and areas with recent burn scars. The National Weather Service has highlighted the potential for heavy rainfall late Sunday into Monday, depending on the interaction of Hurricane Polo's moisture with a developing weather system. While the likelihood of severe storms is low, localized heavy rain could lead to hazardous conditions. Historical data shows that remnants of tropical storms have caused significant flooding in Arizona, underscoring the need for vigilance.