The Monsoon Season Arrives In Sedona
When most people think "desert," they think hot, barren, and dry. While those are all half-acceptable descriptors, the desert has kind of a dual nature.
Sure, it gets hot, with the mid-summer temperatures around Sedona creeping toward 100, but the winter can bring snow, frost and a biting wind, even to lower desert areas.
While parts of the high desert seem like nothing but scrub brush from a distance, a casual hike reveals hidden cacti, wildflowers and lichens, evidence of rodents and deer, and hordes of lightning-quick lizards underfoot. Now we come to "dry."
The Sedona area averages about 17 inches of rain each year; we are indeed in the midst of a drought, the summer is still punctuated by drenching thunderstorms that seem virtually tropical, with water cascading down the red rocks and clogging storm drains.
This is the Arizona Monsoon, a seasonal phenomenon that gets its name from the Arabic word mausim, which means "season" or "wind-shift." While dramatic thunderstorms are the big stars of the monsoon, it's the seasonal shift in wind, from about mid-June to mid-September, that defines the phenomenon.
In the winter, our winds come mostly from the North and Northwest. In the summer, the desert heats up, creating a low pressure area that allows winds and accompanying moisture to swoop in mostly from the Pacific Ocean, the Gulf of Mexico and the Gulf of California. (By the way, the thunderstorms that occur during this time are not "monsoons." "Monsoon" refers to the seasonal windshift. The thunderstorms are just thunderstorms.)
The Arizona Monsoon officially begins when there are three consecutive days of dewpoint above 55 degrees, or three consecutive days of residents feeling inexplicably cranky and damp. The day can start hot and clear, but in the late afternoon, the clouds bring an ominous darkness and the air feels thick and prickly. A rumble or two of thunder, a few big drops of rain, then whammo!
Sheets of water that can bring visibility down to a few yards and highway traffic to a standstill plummet down for a half hour or sometimes more. About 1/3 of the area's annual rainfall comes from the monsoon.
Monsoon Safety - Now, this may seem like paranoia. How much danger does a thunderstorm actually pose, other than the possibility of a lightning strike, and who has the time to worry about that? However, dozens of motorists and hikers each year are taken unpleasantly by surprise by high winds and flash floods that the thunderstorms bring.
When you're driving along during a fierce storm and see a sign that says "DO NOT ENTER WHEN FLOODED," do everyone a favor and believe it. "Surely my car can plow through (what looks like) a few inches of water," you think. The next thing you know the hidden power of the flash flood is sending your car cruising down a wash. Maybe you'll only be humiliated as rescue workers pluck you off the roof of your Hummer. You may even be fined for their services, under the Arizona's "Stupid Motorist Law." (This is a real law, that delivers fines up to $2,000 plus rescue expenses for ignoring a posted or barricaded flooded area.) Or a large wall of runoff water can submerge your car entirely. Hope for the first two.
Another simple rule for driving in a storm: Go Slow. If it hasn't rained for weeks, which is often the case, the surface of the road is chock full of oils and other substances that become slippery in the rain. If visibility gets bad and you're on the highway, gradually slow down and pull over as far to the right as possible. Shut your car off, put your flashers on, and wait for conditions to improve.
If you're hiking and a storm hits, stay out of washes and ravines. You won't be able to see it coming and scramble out of the way. Flash floods work just like the name implies. They're fast, powerful, deep, and come out of nowhere.
Last but not least, we're proud to give you the most excellent meteorological vocabulary word, ever: HABOOB! Go ahead, say it one more time, as loud as you like! HABOOB!!! This one also comes from the Arabic haab, which means wind. Haboobs often happen just before or during the early part of the monsoon, when air gets pulled down the front edge of a storm cell toward the earth's surface. When it hits the surface, this downdraft creates a fast, forward-moving wall of wind and sand, called a "haboob."
Article by Sarah Horton.