This is probably more of interest to my Arizona readers…

“Scientists identified the two factors nearly a year after using planes, weather balloons and on-the-ground weather stations to track the formation of individual monsoon storms in a $1 million federally financed study in the Santa Catalina Mountains northeast of Tucson.

The first factor they identified is the rise of low clouds up an invisible atmospheric layer that spans 9,000 to 19,000 feet in elevation. As cumulus clouds rise from lower elevations, they carry and deposit warm air, getting thicker and taller before developing into storm clouds.

The second factor is local heating over mountains, which can form the same type of clouds that trigger monsoon activity.

‘You look out the window at storm formation, and the clouds sort of bubble out,’ said Joseph Zehnder, an Arizona State University meteorologist and a principal investigator on the study. ‘We’re starting to get understanding of the details of what happens that moment that it goes from the shallow bubbling of clouds into a thunderstorm.’ “

I’ve heard an awful lot about how violent the rain fall can become in the monsoon. (I’ve even got a roofer coming to our home on this week to fix some broken roof tiles before the rain begins.)

It is starting to get a little more humid out here, if you can call 10 or 12% relative humidity humid.

Read the rest here: Researchers ID Factors in Ariz. Monsoons