FLAGSTAFF, Ariz. — Flooding ravaged some Arizona residents last year as the summer rainy season known simply as the monsoon was unleashed on mountains scorched by flames — a problem that residents in the throes of a particularly wild one this year wildfire season was an issue.
With the seasonal weather pattern beginning Wednesday, many are concerned about flooding as wildfires burn more of the ponderosa pine forests around Flagstaff, in northern Arizona, to ash.
The monsoon can be a mixed bag — cooling down muggy cities like Las Vegas and Phoenix, but bringing the risk of flooding to mountain towns and low-lying deserts alike. It promises rain but doesn’t always deliver. And even if it does, the moisture isn’t evenly distributed across the Four Corners region and beyond.
The monsoons left the region largely dry in 2019 and 2020, but took a notable turnaround last year as some cities recorded their wettest summers on record.
The outlook for this year sees equal odds for low, high and normal precipitation, although that could change when a new seasonal forecast is released on Thursday, climatologists said.
Already, conditions are bracing for moisture moving into northern Arizona and other locations later this week, which may help firefighters but also bring dry flashes that could spark more blazes.
“There are many beneficial ingredients associated with it,” said Brian Klimowski, who directs the National Weather Service in Flagstaff. “That’s the relative humidity, which tends to suppress fire behavior, and of course hopefully some rain. But not too much rain. We all know the threat and risk of post-fire flooding.”
Temperatures will warm up a little Thursday and winds will pick up in northern Arizona, potentially leading to more active behavior in two wildfires burning on the outskirts of the city before moisture gets in, he said.
Firefighters have contained about a third of the larger blaze, which has charred more than 35 square miles (92 square kilometers) since it began Sunday. Another wildfire in a more remote area has burned almost 20 square kilometers without containment.
Evacuation orders were downgraded on Wednesday. While the fires have calmed somewhat and are mostly moving away from homes, Coconino County officials are urging residents who don’t have flood insurance to buy them now. Officials are testing sirens in a flood-prone area this week and padding sandbags and concrete barriers to reduce potential damage, but they won’t know the level of risk from the recent wildfires until the area can be surveyed.
“It’s not realistic that we can stop the flooding,” Christopher Tressler, the county’s director of public works, told residents Tuesday night.
The US monsoon is marked by a shift in wind patterns that pull in moisture from the tropical coast of Mexico. Things are different in other parts of the world, including India, northern Australia and Africa, where people are celebrating the first rains of the season, said Joel Lisonbee, climatologist and drought information coordinator at the National Oceanic and Atmospheric Administration.
In Arizona, about half of the rain that falls during the year comes during the monsoon, said state climate researcher Erinanne Saffell. Still, the US Southwest is trending toward hotter, drier weather due to climate change.
These conditions, along with fierce winds, led to a busy wildfire season in the western United States this spring. Overall, federal officials said more than three dozen major fires have burned more than 1,875 square miles (4,856 square kilometers). Over 6,700 forest firefighters and support personnel are deployed to incidents nationwide.
New Mexico is burning with the largest wildfire in the United States, one fire that has scorched more than 523 square miles (1,354 square kilometers) and another that is marching through another corner of the state.
The Weather Service warned of a potentially critical fire hazard in the South Park region and eastern Colorado plains this week. Some local governments banned outdoor fires on Wednesday.
In southwest Alaska, a 570-square-kilometer wildfire has moved through dry grass and brushwood in the largely treeless tundra away from an Alaskan Native village. A front expected to move Thursday will bring southeasterly winds that will reduce the threat to St. Mary’s.
Temperatures were hot in interior California on Wednesday, but incoming low pressure was expected to cool things and bring the possibility of mountain showers and thunderstorms in the north through the weekend. Forecasters noted the possibility of localized fire weather in the eastern Sierra Nevada due to drought and gusts from the approaching system.
Associated Press writers John Antczak in Los Angeles; Susan Montoya Bryan of Albuquerque, New Mexico; Mark Thiessen in Anchorage, Alaska; and Jim Anderson in Denver contributed to this report.
Copyright 2022 The Associated Press. All rights reserved. This material may not be published, broadcast, transcribed or redistributed without permission.
https://www.local10.com/news/national/2022/06/15/summer-rainy-season-sets-up-across-four-corners-region/ The summer rainy season begins in the Four Corners region