If you look at the WeatherRadar, you will see a supercharged monsoon with even heavier downpours than usual. So what's behind this surge of moisture?

You don't see this every day on the WeatherRadar. Low pressure over the Gulf of California is sending showers and storms across parts of the state of Sonora, Mexico. Development into a tropical depression or storm is not expected, but this low is sending plenty of tropical moisture north.

This surge of tropical moisture will strengthen the ongoing Monsoon, increasing the threat of flooding across the Southwest and into the Four Corners.

It doesn't take much rain for flash flooding to occur in the desert. Here's how to turn on your Weather & Radar app alerts.