When will the monsoon really reach the Verde Valley?
While higher-elevation areas around northern Arizona have caught at least cursory amounts of rain in the first two weeks of July, the Verde Valley has not really been able to swim in the coolness of monsoon so far in 2019.
High-altitude clouds have cooled the valley somewhat, but the dry heat has pervaded — and will likely continue for nearly one more week.
David Byers, a National Weather Service meteorologist based in Flagstaff, said the monsoonal flow has been timed to bring the right kind of clouds to the Verde Valley. Unfortunately, clouds have been forming higher above the valley than usual.
The rain falling from those high clouds has mostly not been reaching the valley floor, Byers said.
“Normally, we see clouds form right above us, even in the valleys,” he said. “This year, the same types of thunderstorm clouds are still forming, for the most part, but at more of a mid-to-high level.”
The National Weather Service forecast is for no rain chances above 20 percent until Monday, July 22 — and even on that day, chances are only 30 percent. The forecast high temperature will be at least 102 each day through Saturday, before dropping off by a few degrees.
“We should see much lower clouds next week, and that should get rain going in the Verde Valley,” Byers said. “Clouds that just hover overnight only make things warmer.”
While some rain has fallen on mountaintops, other areas not as low as Camp Verde (3,147 feet above sea level) have still struggled to pull in much moisture. Jerome, at about 5,000 feet, has only pulled in a tiny amount of rain so far, as have Flagstaff and Payson.
There was a thunderstorm warning issued last weekend, briefly, for Jerome. There was also a warning issued for Bumble Bee, 67 miles to the south of Jerome.
Monday was the hottest day of the year at Phantom Ranch, along the Grand Canyon’s North Rim, at 2,500 feet, where it was 109 degrees.
Byers said once rains begin, flooding is a concern, along with poorly prepared citizens, who are not yet in “flood mode” for the season. He said two-thirds of all deaths during floods happen with people who are in vehicles, so the motto “turn around, don’t drown” is more than just a cliché to the Weather Service.
“Lightning is always a summer concern as well,” Byers said. “Get indoors when you hear thunder.”
Byers said the degree of flooding always depends on how much rain is falling in a short period of time.
However, the amount of downstream flooding grows with more days of rain, as ground thirsty for water keeps flooding local, while saturated soil tends to spread flooding further downstream along local watersheds.
Byers said it’s tough to tell how things will shake out for the Verde Valley in terms of total summer rainfall. A slow start doesn’t necessarily lead to a dry monsoon season.
He also said until the rains pick up and cool the valley down somewhat, everyone should continue to follow protocol for high temperatures. Tuesday’s forecast high for Camp Verde was 106, with virtually no wind, and an excessive heat warning that extended beyond sunset.
“Stay hydrated,” Byers said. “Plan to be out in the sun as little as possible, and plan some cool-down time afterward.”