Flash Flood — Gila, Arizona

2021-07-29 · near Miami, Gila, Arizona

Event narrative

After 2.5-3.5 inches of rain fell over the northern portion of the Telegraph burn scar, runoff rapidly collected in Bloody Tanks Wash and flowed downstream through the town of Miami causing catastrophic damage. A rain gage in Russell Gulch to the south measured 2.01 inches of rain between 1316MST and 1414MST with a brief period where rain rates were as high as 8-9 inches per hour with 0.87 inches measured in 10 minutes. At 1438MST Arizona Department of Transportation (ADOT) reported US-60 was closed in both directions at mile post 243 due to water moving over the road. Between 1440MST and 1500MST, a trained spottered reported the flood water was coming out of the banks of the wash at the intersection of Canyon Avenue and US-60 and video showed 6 to 8 feet of flood water in the wash coming up to the base of multiple bridges between Sullivan Street and US-60. Water and mud spilled out of the wash near Cordova Avenue, with flow down Sullivan Street, and entered homes and businesses. ADOT ended up having US-60 closed in both directions between Miami and the town of Superior until 1920MST. According to Gila County Emergency Management and Arizona Department of Emergency and Military Affairs, approximately 600 homes and 10 businesses experienced some form of flood damage. No injuries were reported and the full extent of damage costs are unknown.

Wider weather episode

A westward moving upper level trough over northern Mexico helped place much of Arizona under broad difluent flow aloft, aiding in the development of thunderstorms across the state. Scattered thunderstorms developed during the afternoon on the 29th across the high terrain of Arizona as daytime heating led to increasing upslope flow along terrain features. Abundant moisture in place allowed for thunderstorms to produce locally heavy rainfall, which led to instances of flash flooding across south-central Arizona. Thunderstorms over southern Gila County produced heavy rainfall over multiple burn scars, leading to enhanced runoff and flash flooding. The most significant impacts occurred after thunderstorms over the recent Telegraph fire burn scar produced 2-3 inches of rain, resulting in rapid rises in Bloody Tanks Wash and Russell Gulch. This resulted in catastrophic flash flooding in Miami where numerous homes, businesses, and roads were inundated with flood waters. A rare Flash Flood Emergency was issued for Miami due to the catastrophic flash flooding. No injuries were reported.

View location on OpenStreetMap → (33.3905, -110.8876)

Source: NOAA Storm Events Database, event_id 977463. Narrative written by the NWS forecast office that issued the report.