Images and video footage uploaded to social media show an imposing dust storm bearing down on Phoenix, Arizona, as the region sees its first monsoon of the season after facing an extended heat wave.
Thousands of residents were left without power on Wednesday night as up to an inch of rain fell on parts of the metropolitan area, marking a reprieve from an “oppressive” bout of hot temperatures in the southwest that regularly reached over 100 degrees Fahrenheit.
The National Weather Service (NWS) in Phoenix said that as of 11 p.m. local time on Wednesday (2 a.m. ET Thursday) the temperature at the city’s airport had fallen below 90 degrees for the first time since the morning of July 9.
The monsoon season in northern Arizona runs from June 15 to September 30, but the NWS says that the weather phenomenon usually does not reach the area until early July, generally bringing as much as half of the area’s annual rainfall. Meteorologists at the agency said ahead of the storm that it was hoped to “finally break the ongoing streak of no measurable precipitation at Sky Harbor [International Airport].”
One image, taken from the airport and posted on Twitter on Wednesday evening, shows the dust storm rolling over Phoenix and toward the runway. In the image, a tall orange cloud can be seen on a stormy, dark grey background.
The NWS in Phoenix said that the dust storm had been rolling northward through Pinal County, to the southeast of the state capital, with 60mph wind gusts and a quarter of a mile of visibility shortly before 9 p.m. local time.
Around the same time, it issued a dust storm warning while noting “difficult driving conditions” along parts of the I-10 near Casa Grande, a city in the county. Images taken by professional storm chaser Mike Olbinski show the dust clouds arching over streetlights in the municipality.
The NWS said shortly after that the storm had progressed and was moving through the Phoenix area with 40-50mph winds and visibility of less than a mile. It urged locals not to travel during the storm.
Time-lapse footage taken from a rooftop camera in the city shows the dust cloud rolling in from the horizon before completely blanketing the surrounding buildings and streets.
Video uploaded by resident Andy Richards shows lightning flashes as the dust storm begins to stretch over Tempe Town Lake, a reservoir on the Salt River to the east of Phoenix city center. And Olbinski caught a snap of the dust cloud as it began “engulfing” downtown Phoenix.
It is unclear whether the reduced visibility caused by the dust storm led to any road collisions. Newsweek approached the Arizona Department of Public Safety via email for comment on Thursday.
The NWS said that between a quarter of an inch and an inch of rain fell across Phoenix and the wider Maricopa County during the storm, with the highest amounts falling over the Uptown and Paradise Valley areas.
Local news station KTAR reported on Wednesday evening that around 27,000 residents had been left without power as a result of the storm.
As of 4:45 a.m. ET on Thursday, Arizona Public Service was reporting 21 outages in the Phoenix area with 4,862 residents affected, while the Salt River Project had nearly 14,000 customers still without power.
In its latest forecast discussion, the NWS said isolated thunderstorms that could whip up more dust were possible in the coming days, with a greater chance of rain on the weekend.
However, it cautioned that a “relentless, record-breaking” heat wave will continue with excessive heat warnings remaining in place through Friday. On Thursday, the NWS anticipates a high of 119 degrees Fahrenheit—making it potentially the fourth time this month the area has reached such high temperatures.
The heat Arizona has faced this summer has created the perfect conditions for wildfires, which have been causing disruption in Europe and Canada. In late June, a wildfire near Phoenix spread across nearly 2,000 acres and led to the evacuation of over 1,000 residents.