In the Navajo vernacular, this time of year we often get what is called male rain, níłtsą́ bikąʼ. These are drenchers that come on strong and swift, rutting out driveways, turning the river a sudden brown, and they’re usually finished just as fast as they started. This happens when upwellings of heat from the ground collide with cool, moist skies. Other times of the year and in more stable conditions, you get what in Navajo is called female rain, níłtsą́ biʼáád, which falls soft and long, the kind of precipitation that saturates the ground and wets the roots of plants. I’d take either any day, but in the high summer into fall, male rain rules.
Driving a lonely two-lane home from Wyoming, I noticed a silver slash across the highway ahead. Wyoming was just as hot as Colorado, just as hot as about everywhere, and I saw no rain in its scattered clouds. Knife blades of virga reached toward the ground but didn’t make it all the way. As I drove closer to this line across the asphalt, slowing from 70, I could see the air three feet above it misted from exploding raindrops. It wasn’t only rain, it was a fierce rain, and it occupied a space that looked to be fifty feet wide at most, the highway dry to either side. I craned under my windshield and saw a faintest band of gray overhead where a slice of precipitation had fallen out of its cloud. The rain didn’t begin with a drop or two. It came all at once. I sped into a blinding downpour, double-fisted on the steering wheel, eyes dead ahead. My roof and hood sounded like a hail of pea gravel, windshield wipers throwing water everywhere. In another second I broke out the other side trailing a rooster tail of haze. The roar ceased and I kept driving into a dry, sunny day. That was the níłtsą́ bikąʼ, male rain.
In meteorological terms, this would be called a downburst or microburst, a column of falling air that impacts a couple square miles on the ground. It happens when a cloud reaches its maximum precipitation load at the same time that its bottom is warmed from the Earth below, while the head is colder than freezing. The belly splits and rain is ejected to the ground with wind speeds that can reach 150 miles per hour. In this case, I’ll call this event a mini-microburst. Wind speed I’d guess at 50 to 80 mph based on the sudden jolt as I crashed into it.
A microburst is different than a derecho, which is a cluster of microbursts. These clusters can form a line of squalls 400 miles long, a source of tornadoes and widespread damaging winds. In Spanish, derecho means “right,” “direct,” or “straight ahead.” The name comes from a long line of violent downdrafts all moving the same direction.
Then there is what meteorologists call a bow echo, which can be as big as a derecho or as small as a microburst. You’ve probably experienced one. I was listening to live music at a restaurant in my little town when an absurdly bright double rainbow arced across the highway. A plum-dark thunderstorm was heading the other way and evening sunlight struck just right. We left our tables and meals, walking to the sidewalk to watch the atmosphere show off. The musician took a break to come see. We were all thinking rain had missed us on its way to the mountains. Though the storm was going away from us, we noticed the rainbow was coming our way, and when it reached town, it brought an intemperate and chilly wind. Shade umbrellas at the tables had to be quickly closed as dust swept up the highway, followed by a crisp, ice-cold rain. People grabbed their plates and hustled inside while the musician quickly pulled plugs on his soundboard and speakers.
I’m not sure how I feel about this being called male rain. There are times I also am quiet and soft, that the ground isn’t hammered by my steps. But when I look at me and the men around me, we can be bulls in the china shop. There’s a reason this rain is named after us. At the restaurant we were in a bow echo and it happens when an updrafting thunderstorm tilts forward as it travels, and the rain claws backwards, increasing the pool of cool air behind the storm, sending out gusts and precipitation. The air that landed on us was from the troposphere, pouring down from ten miles high, which made its arrival instant and violent. Where the backside of a bow echo touches ground is like a razor cut. A quarter mile out of town, roads were dry.
When the storm moved off, food came back out. The musician, a local songwriter, a man, pulled up a stool and decided to go acoustic for his next set in case the rain came back. As gutter water trickled and sunlight shot down the highway, he drove at his guitar, which sounded like a wild prayer for more rain.
Photo by Craig
