A heightened risk of flash floods will continue across northern Arizona through Saturday, according to the National Weather Service.
A recent pattern of weak atmospheric winds means any storm that develops will move through the area very slowly, said Tim Steffen, a meteorologist at the Weather Service’s station in Bellemont.
In addition to that, moisture is “pretty much entrenched in the area,” Steffen said. A weather balloon the weather service launched on Thursday measured moisture in the air at 40 percent above normal for this time of year, he said.
What that means is storms are able to produce a lot of rainfall in a short amount of time. That, combined with slow-moving storms increases the risk of flash flooding, Steffen said.
When such a risk exists, the weather service recommends people have a reliable way to receive weather warnings either via cell phone or a NOAA weather radio and avoid slot canyons, other flash flood-prone areas and areas where there isn’t access to higher ground. Drivers should never drive into flood waters.
The cumulonimbus clouds that bring the summertime downpours are tall with a cauliflower-like top. They will get taller and taller as storms develop and the rain shaft will be visible at the bottom, Steffen said.
During the monsoon, the weather service closely monitors recent wildfire scars, including the area of this spring’s Tinder Fire near Blue Ridge. So far, a couple of storms have moved over that area but the amount of precipitation that fell hasn’t yet approached thresholds that should be cause for flooding concern, Steffen said.
The weather may turn slightly drier early next week, but scattered afternoon storm activity is expected to continue, he said.