The National Weather Service in Tucson has issued a Flash Flood Watch, from 1 a.m. Saturday to 5 a.m. Sunday, for a portion of southeast Arizona, including the Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley and White Mountains of Graham and Greenlee Counties.
Widespread showers and thunderstorms are expected to develop overnight along the International Border from Santa Cruz through Cochise Counties. The potential for heavy rainfall gradually spreads to the north and northwest through Saturday morning and afternoon, continuing during the night. Localized rainfall amounts could exceed 1 inch in less than an hour, with storm total rainfall possibly above 3 inches in spots. While the heaviest precipitation typically occurs in the afternoon and evening during the monsoon season, this event extends that potential to all hours of the day and night.
These rainfall rates can result in strong, rapidly rising water in area washes which may create hazardous conditions at low water crossings.
A Flash Flood Watch means that conditions are becoming favorable for widespread flash flooding to develop. Monitor forecasts closely and be ready to take quick action if Flash Flood Warnings are issued.
Be especially cautious at night when it is harder to recognize the dangers of flash floods. If Flash Flooding is observed, act quickly. Turn around and take another route.