Flagstaff could endure sustained rains, flash flooding this week. Here's how to stay safe
The Flagstaff area, along with much of northern Arizona, is likely going to experience a wide range of monsoon activity in the coming days.
The rain that started to fall in Flagstaff mid-afternoon Monday could taper off before the end of the night but it could also carry through to the next morning and then throughout the day Tuesday, according to National Weather Service meteorologist Paige Swenson.
When the rain suddenly intensified, the National Weather Service and Coconino County declared a flash flood warning at 3:20 p.m. extending at least until 6:15 p.m.
In less than two hours Monday, areas in south Flagstaff and around Northern Arizona University received between one and three quarters of an inch of rain. This caused temporary flooding of a busy stretch of Milton Road and Route 66 which forced traffic to slow to a crawl as cars made their way through the water-filled roadways.
The areas most at-risk of post-wildfire flooding escaped the worst of Monday afternoon's rainfall though the small amount of water was enough to muddy up much of the shoulder of U.S. 89 heading north out of Flagstaff where flooding forced a road closure July 14.
"This stretch (of monsoon activity) has definitely been pretty active, we haven't seen a huge break in it which has definitely been a little bit of a change so far this year," Swenson said.
The most recent rainfall comes as thousands of homes and businesses around Flagstaff work to recover from recent flash flooding with dark storm clouds looming above.
In the past weeks, the Coconino County Flood Control District has been working with the Arizona Army National Guard and countless volunteers to fill and distribute tens of thousands of sandbags throughout the community.
This flood mitigation managed to hold up throughout some minor rainfalls over the weekend but will likely face much heavier rain this week.
"The impact that we can always be mindful of is definitely going to be flash flooding, especially in areas that are near recent burn scars," Swenson said.
So far this year, the Doney Park, Fernwood, Timberline and Wupatki Trails neighborhoods have experienced severe flooding from the nearby Pipeline and Museum Fire burn scars that bring with them ash and debris, which can be dangerous.
In June, the City of Flagstaff along with the Coconino County Flood Control District and the Arizona Department of Forestry and Fire Management implemented a new siren alert system for the neighborhoods downstream of the Museum Fire burn scar.
When 0.75 inches of rain falls on this burn scar in a 15-minute time span, an alarm will sound, followed by a voice message alerting of imminent flash flooding. Residents in this area will also receive text messages that include an alert as well as safety instructions.
Valley could see flood activity, too
A flood watch also was issued for most of central and southern Arizona, as well as parts of northern Arizona, until 5 a.m. Wednesday. According to the National Weather Service’s website, a flood watch is issued when flooding is possible, while a flood warning is issued when flooding is about to happen or is actively happening.
There likely will not be a blanket coverage of rain spanning multiple counties. In the Valley, the weather service said “pop-up” storms are expected throughout the week, with small-area thunderstorms they say will be difficult to predict.
“It’s going to be pretty sporadic, at least for the middle of the week,” said Bianca Feldkircher with the National Weather Service in Phoenix.
How do I stay safe?
Coconino County officials offered the following tips online and advised residents to be prepared for the approaching storms and potential flooding threat. They further recommended that residents sign up for emergency alerts and remember to be in READY status for potential emergencies.
Plan for sheltering where you are and for evacuation.
Evacuate if advised by authorities.
Seek high ground (flash floods) or stay on high ground.
Avoid walking or driving in flood waters.
Do not attempt to evacuate through flood waters. Depth and velocity are not always obvious; the ground or road may suddenly wash away and hidden dangers may exist.
Avoid injury from debris, contaminated water, carbon monoxide poisoning, electrocution, and damaged buildings and infrastructure.
Protect your property from floodwaters and purchase flood insurance.
Seek professional review or inspection of structures and utilities before entering buildings that have been flooded.
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: Flagstaff could endure sustained rains, flash flooding this week
