The heavy rainfall poses a significant risk of flash flooding across Arizona, particularly in areas under the Moderate risk zone, including Phoenix, Globe, Payson, Casa Grande, and Tucson. Flooding could occur in washes, streets, and even larger rivers, creating hazardous conditions for residents. Additional risks include damaging winds over 60 mph, hail, and dangerous cloud-to-ground lightning. Motorists are advised to avoid driving through flooded roadways or washes, as conditions can change rapidly and become life-threatening.