Thunderstorm chances increase for Phoenix, south-central Arizona

Chances of thunderstorms and typical monsoon weather return to the Valley and a majority of south-central Arizona on Thursday, bringing an increased threat of flooding for portions of the state.

According to the National Weather Service, the likelihood for thunderstorms developing throughout the Phoenix area and portions of the lower deserts sits at 30% to 40%.

The weather service added that some storms have the potential to be "strong to severe," with the main impacts being heavy downpours, strong winds and frequent lightning.

"The best chance is probably across the west Valley today, and that is likely going to be during the evening timeframe," meteorologist Chris Kuhlman, of the weather service's Phoenix office, told The Arizona Republic.

According to Kuhlman, some storms unlikely to reach Phoenix will begin forming to the east, but those originating near Tucson and across Pima County have a higher chance of pushing into the Valley's radar.

"Those are the storms we are kind of worrying about and will have a higher likelihood of getting outflow winds from those storms and maybe some dust this evening," Kuhlman said.

Due to the potential of strong winds, a blowing dust advisory has gone into effect for swaths of Maricopa and Pinal counties, the weather service said in a post to X, the social media site formerly known as Twitter.

The advisory lists the effective time from 4 p.m. to 9 p.m. on Thursday, with wind speeds reaching about 35 mph but could exceed it.

"There's a pretty high likelihood of having some outflow winds today, it could be higher than 35, it's just going to be hard to tell until the storms get going," Kuhlman said.

As for temperatures, Phoenix is still expected to see hot conditions, with a high forecast at about 110 degrees for the day. Thursday's low, as of this report, was listed at 92 degrees from Phoenix Sky Harbor International Airport, about 10 degrees above average for this time of year.

If that low holds until midnight, it will set a new warm low record for that date, previously established in 2007 and tied again in 2011 at 91, according to the weather service.

Storm chances increase further on Friday

With the current forecast, Thursday's thunderstorms are on-call for the night shift as moisture levels are on the rise heading into Friday with low-pressure troughs moving on down from the north.

"We'll have a chance of storms and showers overnight and then again Friday in the afternoon. That's probably a better chance for the Phoenix area," Kuhlman said.

The odds are much more favorable for Friday, slated at about 60% to 70%, bringing heavier rainfall due to that increase in moisture from the south. The high temperature for the day is listed below 100, if you can believe that, floating between 95 and 98 degrees.

It will also help dispel the possibility of stronger winds developing through the duration of the day, holding them to be more localized rather than widespread.

However, the low-pressure trough that is helping increase rain chances will also bring a "cold front" through the Grand Canyon state during the bulk of Labor Day weekend, eventually drying it out.

"That trough eventually is going to kind of bring a cold front through here Saturday night and Sunday. It's not going to cool us down dramatically or any at all really, but it'll keep us from warming up, and it'll really dry us out," Kuhlman said.

Kuhlman added that the drying trend will continue throughout most of next week and temperatures will eventually begin to rise again, hitting "above-normal" numbers come midweek.

This article originally appeared on Arizona Republic: Rain forecast for metro Phoenix, south-central Arizona