Monsoon rains slammed Arizona’s East Valley, flooding roads and stopping traffic during the early morning hours of Aug. 10.
Highway 60 through Tempe was shut down completely as water rose higher than the wheels of cars, stranding some drivers.
Drivers had to abandon their cars as floodwaters continued to rise. Tow vehicles had to retrieve the stalled vehicles after the worst of the storm passed.
AZFamily reported that more than three-and-a-half inches of rain fell in an hour on parts of Highway 60.
Two eastbound off-ramps—Ellsworth Road and the Loop 101 northbound, had to be closed because of mud, ADOT reported.
The National Weather Service issued a Severe Thunderstorm Warning for the area at 11:45 p.m. on Aug. 9, but no one was prepared for the ferocity of the rainstorm which assaulted the region just a few minutes later.
Severe Thunderstorm Warning including Phoenix AZ, Glendale AZ, Peoria AZ until 11:45 PM MST pic.twitter.com/Ki1lGtO3qq
— NWS Phoenix (@NWSPhoenix) August 11, 2018
The Arizona Department of Transportation closed Highway 60 around 1:30 a.m. local time, and kept it closed for about three hours.
Roads around the University of Arizona’s Tempe campus were also shut down.
The National Weather Service issued flash-flood and severe weather warnings for several other regions of the state as the powerful storms blew through overnight.
12:45 AM: A new Significant Weather Advisory is in effect for areas of SR 87 near Tonto Village, Starlight Pines, and Clint's Well until 1:30 AM for a strong thunderstorm capable of 40 mph gusts and nickel sized hail. #azwx pic.twitter.com/FtYJMzpI8z
— NWS Flagstaff (@NWSFlagstaff) August 11, 2018
Apache Junction had to shut down several roads as well, but got most of them open by 7 a.m.
Heavy rain…winds…lightning…It is Friday night so be careful out there! #azwx pic.twitter.com/IK9kPmx6eF
— NWS Phoenix (@NWSPhoenix) August 11, 2018
Monsoon Causes Power Outages
The monsoon brought rain, but it also brought fierce winds, up to 50 mph in some areas. The combination of wind and rain caused widespread power outages throughout the East Valley.
Along with flooding, Apache Junction got hit by high winds which left some 13,000 residents in the dark. Power was restored for most of them by 4 a.m., AZFamily reported.
The Small Stream Flood Advisory remains in effect until 945 AM MST for South Central La Paz and North Central Yuma Counties. https://t.co/WFGrYlAGMD #azwx pic.twitter.com/ZuMeACULxW
— NWS Phoenix (@NWSPhoenix) August 11, 2018
More Rain on the Way
Arid Arizona has been hit by three days of monsoon weather this week, with heavy rains, high winds, and even dust storms disrupting residents’ travels, electricity, and their lives in general.
Berto Sundowning filmed one such sandstorm which blanketed him while driving on Aug. 8. Visibility dropped to near zero, forcing cars to stop.
Unfortunately, several drivers opted to stop on the roadway, right in the middle of the traffic lanes, rather than heading for the breakdown lanes.
Significant Weather Advisory for Northwestern La Paz, San Bernardino and Riverside Counties until 900 AM MST/900 AM PDT/. https://t.co/iYpbIkbZ5l #azwx pic.twitter.com/UPjE8XxTNo
— NWS Phoenix (@NWSPhoenix) August 11, 2018
According to the National Weather Service, rains, wind, and flooding can be expected throughout the weekend.
Thunderstorms that develop over north-central Arizona this afternoon will move west into Mohave County, Colorado River Valley, eastern Clark and San Bernardino Counties. Be Alert for strong winds and heavy rain. #azwx #cawx #nvwx pic.twitter.com/o2vVCafJsx
— NWS Las Vegas (@NWSVegas) August 11, 2018
Gusts are again predicted to reach 50 mph, and flooding is also predicted, so further power outages can also be expected. Central Arizona residents would do well to stock up on candles.
Worse and Wetter Than Usual
Arizonans expect a monsoon season halfway through summer, but the storms this year have been harsher than usual, AZCentral reported.
This, on top of a trend toward fewer but more powerful monsoons each season is forcing Arizonans to adopt new habits—like learning not to drive through waist-deep puddles or parking in the middle of the road when sandstorms hit.
In 2017, researchers at the University of Arizona published a study showing that storms since the 70s have grown more severe, dumping more precipitation.
Study co-author Christopher Castro told AZCentral, “If you look at the distribution of daily rainfall, what’s happening is you’re getting more events on the far right end of that distribution, the really extreme precipitation events.
“What the study shows is we’re getting more of those (extreme storms) and maybe events we haven’t seen before as compared to 50 to 60 years ago.”
According to the study central Arizona (including the Phoenix area) and southwest Arizona (including Yuma) are getting hit with harsher storms, while the weather in the rest of the state is pretty much following normal patterns. But the affected areas can expect to be heavily affected.
“The monsoon is the main severe weather threat in Arizona,” Castro said. “Dust storms, wind, flash flooding, microbursts—those are the things that are immediate dangers to life and property.”
That study was published in the July 3, 2017, edition of the Journal of Applied Meteorology and Climatology, and almost seems prescient given this week’s weather.