Staff Writer, DB HolmesWeather / Air Quality
The east Valley is experiencing Ozone in the Moderate range this evening, ahead of another storm system.
Forecast Discussion: Mild weather and some afternoon breezes are expected today. Starting tomorrow afternoon, cloud cover increases ahead of a low-pressure circulation entering southern California. The system will cross over Arizona Friday and Saturday bringing a chance of showers and isolated thunderstorms. The higher terrain east and north of Phoenix has the best shot for measurable rainfall, but can’t rule out trace amounts even in the deserts as the low circulation passes overhead. Where thunderstorms do pop up, localized blowing dust from outflows could result, leading to higher PM-10 values. High temperatures will take a dive into the mid 80s under mostly cloudy skies on Friday, which may actually limit instability for thunderstorm development. Also, many monitors are beginning to observe elevated readings for ozone into the Moderate range and this will continue for the rest of the week.