Thursday, April 24, 2014

Changes for the Weekend, Wind, Rain, and Unseasonable Temperatures

Staff Writer, DB Holmes
Weather / Air Quality

More wind, a spatter of rain, and cooler temperatures for this weekend. Unseasonable and unusual weather but most likely the last Phoenix will see of below average temperatures until November. Saturday's light rain event might be all Phoenix sees in precipitation until the start of the Monsoon season the first week of July.
Forecast Discussion: The models have been pretty consistent with the next weather system slated to impact our forecast area later Friday through Saturay. Winds will increase out of the southwest between 10 and 20 mph Friday afternoon. There's a little break overnight, but winds will pickup again around noon on Saturday, gusting around 25 mph at times. Wednesday's episode did trigger some dust across part of the Valley with many monitors reaching the lower Moderate range of the Air Quality Index (AQI). This will likely happen again Friday and Saturday before the winds ultimately clear the air. Expect PM10 levels to reach the middle Moderate range Saturday. Ozone concentrations will likely push well into the Moderate range today ahead of the system, aided by some import from the west. Levels improve Friday through the weekend with stronger winds, especially when the winds turn out of the northwest on Sunday. Models still project highs in the low 70s on Saturday with a slight chance for a shower or two. Amounts won't be impressive, but the desert enjoys anything wet that the sky will provide. Highs push back into the low 90s by next Tuesday. 

Source: AIRNow, Weather Channel