Monsoon 2022: Northern Arizona seeing more rainfall than normal. Here's why

Almost every location recording rainfall totals across northern Arizona reported measurements far above what they would have normally experienced by this point in the summer monsoon season, according to data from the National Weather Service.

"The next one to two weeks also seem like they're going to be pretty active and wet in a lot of the area," said Justin Johndrow, a weather service meteorologist.

"So that's just going to add on to these totals and maybe even get farther above normal over the next couple weeks," he said.

The departure from the normal rainfall varies widely across northern Arizona, with many places reporting between a half-inch to 2 inches more rain than usual.

But the rainfall totals in a few places including Bellemont, the Heber Ranger Station, Prescott's Sundog Water Plant as well as Sunset Crater and Walnut Canyon national monuments recorded over 3 inches more rainfall than they typically receive at this point in the season.

The increased recorded rainfall can likely be contributed to an early start to the monsoon season in addition to moisture coming in from Northern California, said Lee Born, staff meteorologist for KNAU and faculty at Northern Arizona University.

"It really aided in bringing deep Gulf of California moisture into Arizona," Born said. "Just where that high-pressure cell set up, it just really ramped up our moisture values across the state and we had a bunch of moisture to work with there for a couple of weeks."

Only three locations recorded rainfall less than the area's typical average but these deviations were minimal, involving less than half an inch of rain.

But when looking at the monsoon season as a whole, "It kind of all washes out in the end," Born said.

Because monsoon rains are so spotty, Born said, by this point in the season it's not particularly surprising there is such a wide range in rainfall totals across Northern Arizona so far.

For example, Flagstaff airport has gotten only 4 inches of rain while the east side of the city has gotten more than 10 inches. That means the airport has recorded just around half of the rain it normally does by this point in the year while other areas have seen a 200% increase. As the season continues, storms will likely impact areas like the airport that haven't seen much rain yet, bringing the rainfall totals closer to normal.

"In the end, we'll probably all be right around the same place," Born said. "So how great this last four weeks of rain has felt, we're still half of normal just in 2022."

With the increased rainfall, some areas, particularly those around wildfire burn scars, have experienced extreme flash flooding repeatedly this summer. Flagstaff residents on both sides of the Pipeline Fire burn scar have been dealing with weeks of sustained rains and flooding that have brought with them sediment and debris from the scorched mountainside.

But this flooding, while more extreme this year than most, can sometimes be a necessary hazard when dealing with such prolonged drought conditions, Johndrow said.

"Obviously it's unfortunate that it's caused this flooding but to get runoff into the rivers and the reservoirs, it's going to cause some flooding at times so there's really no way to avoid that," Johndrow said.

"We really don't get, especially in the summer, long gentle rains that fill reservoirs," he said. "It comes in large storms that have heavy runoff and flooding that helps fill those lakes."

With weeks of monsoon season still ahead, the city of Flagstaff met with community members Thursday evening at City Hall to address the concerns of residents living on the west side of the Pipeline burn scar and discuss short- and long-term mitigation efforts.

"The decision to hold a community meeting was made as we have seen multiple flood events to date, and we want to provide another opportunity to make sure residents have all of the information they need as we continue through monsoon season," said a spokesperson for the Flagstaff mayor's office.

Storms are expected to continue this weekend in the Flagstaff area. According to a weather service forecast Friday, isolated to scattered thunderstorms are possible Friday and Saturday with afternoon temperatures a bit warmer due to the reduced cloud cover and precipitation.

"Storm chances increase on Sunday with scattered to numerous thunderstorms expected each afternoon through the middle of next week," the forecast stated.

Contact northern Arizona reporter Lacey Latch at llatch@gannett.com or on social media @laceylatch. Coverage of northern Arizona on azcentral.com and in The Arizona Republic is funded by the nonprofit Report for America and a grant from the Vitalyst Health Foundation in association with The Arizona Republic.

This article originally appeared on Arizona Republic: Monsoon 2022: Northern Arizona rainfall totals far exceed normal