After weeks of scorching temperatures and a lackluster monsoon, Phoenix may finally catch a break. Thunderstorms are moving toward the Valley starting Aug. 21, bringing cooler temperatures, strong winds, blowing dust — and maybe even some rain.
Storm chances in Phoenix start around 20% on Aug. 21 and could increase to 40% in some areas this week. The main threats are strong winds and dust, though some locations could experience periods of heavy rain.
“We’re looking at an increase in monsoonal activity as we go forward through the rest of the week, and that will continue into next week as well,” said Isaac Smith, a meteorologist with the National Weather Service in Phoenix.
Rain could be hit or miss, but a blowing dust advisory from storm outflows is in effect for parts of northwest Pinal County and the southeast Phoenix area.
Storm chances will increase next week — up to 50% on Tuesday, Aug. 26 — after the monsoonal high-pressure ridge moved over the Four Corners region, the ideal position to summon monsoonal moisture into Arizona.
Temperatures will remain well above average in the 110s for the remainder of the week, with the highest temperatures expected on Aug. 21 reaching up to 113 degrees. The National Weather Service has issued an extreme heat warning for Phoenix through Aug. 22.
But precipitation could lower temperatures going into the weekend, and Smith predicts a stronger cooldown next week with highs in the 90s.
He urged residents to follow warnings for both storms and extreme heat.
“Everyone should make sure to exercise proper safety precautions, staying cool and hydrated,” Smith said. “In terms of thunderstorms, everyone should stay weather aware, stay up to date with the latest weather conditions, and heed any warnings you receive.”
The Arizona Department of Environmental Quality also issued a high ozone pollution advisory for Aug. 21 that could extend into the weekend due to blowing dust. Ozone pollution can endanger vulnerable populations like children, older adults and people with heart or lung disease and asthma.
Hayleigh Evans writes about extreme weather and related topics for The Arizona Republic and azcentral.com. Email her with story tips at hayleigh.evans@arizonarepublic.com.