As my family and I sat down for dinner Monday night, we marveled at the sky not too far off in the distance. We saw the dark and menacing storm clouds and the rain that was falling.
Above us, we had blue skies.
We weren’t halfway through dinner when our blue skies turned dark gray. Soon the dark clouds were accompanied by lightning and thunder. The thunder was so loud we could feel it crackling overhead.
Then, everything broke loose.
Within 10 minutes, the sky had transformed from blue with fluffy white clouds into an torrential downpour.
The rain was accompanied by winds that had to be at least 40-50 mph, making it fall practically sideways. In less than five minutes our back porch was flooded and the door mat was floating away.
The rain was falling so heavily that we could barely see the back fence, except for maybe during the occasional flashes of lightning.
The shade structure over our garden was whipping around, snapping one of the heavy-duty PVC pipes in half.
As quickly as the storm arrived, it was over.
Welcome to monsoon season in Southern Nevada.
The season coincides with our warmest months, usually the beginning of July through the end of September.
According to meteorologist Chris Outler of the National Weather Service’s Las Vegas forecast office, monsoons are the result of our warm air mixing with moist tropical air.
He said the region’s westerly winds typically bring dry air to the area but those winds tend to reverse in the summer, bringing in the moist tropical air from the western Pacific and Mexico.
Although the tropical air cools us off a bit, it also creates an unstable atmosphere, causing clouds and thunderstorms by the late afternoon and evening.
Outler said the one of the characteristics of these storms is that they are efficient at producing heavy rainfalls in a short amount of time.
When you mix lots of rainfall with our desert soils that can’t absorb that much water in that short amount of time you get flash flooding, he said.
“If you get under the core of a good thunderstorm, rainfall can easily exceed 1 inch per hour,” Outler said.
Although the experts can usually predict when the general area can expect the thunderstorms — including those forecast for later today — pinpointing exactly where they will happen is a bit trickier.
Outler said the monsoons here are highly variable. You can find one area where rain is falling at an inch an hour and another a few miles away that just has sprinkles. He said they typically affect small spacial areas.
That is exactly the reason why we need to be watchful of our surroundings and the weather conditions. These storms are swift and somewhat unpredictable.
“One of our mottoes is when thunder roars, go indoors,” Outler said. “If you can hear thunder, you are close enough to be struck by lightning.”
The flooding caused by the heavy rainfall is just as dangerous. In a area that is famous for its gambling, Outler said risking crossing a flooded street is too big a risk and not worth the gamble.
“It doesn’t take much water to knock you off your feet,” he said.
At Lake Mead National Recreation Area, the monsoons pose a threat to those on land as well as water. For the Fourth of July weekend, the Park Service issued an advisory to those visiting the park to be watchful for monsoons because they can be extremely hazardous.
Last year on July 8, for example, a thunderstorm over Boulder Basin created 5-foot waves and reports of 8-foot swells on the lake. That storm brought in more than 70 distress calls from boaters, 11 of whom required rescue. It also sank one boat.
Despite its potential danger, our drought-stricken region could use a bit more water. I know the plants in my garden showed their appreciation with bigger and greener leaves.
The air after the storm was also cool and refreshing.
Just by watching the forecasts and avoiding threatening situations, we should all be able to weather the monsoon season.