Thanks for all the valuable information. I didn't know about the "old school" methods of using the DP's as an indicator. I agree with you, this is more or less a "transitional" phase in the pattern from what I see and my gut is saying. Nevertheless, the Monsoon officially starts on June 15th and ends Oct 1st. Last year was a big bust so I'm sure the valley and the mountains are ready for Monsoon action. Fires have erupted up in FLG and ppl are getting worried bc of all the brush that dried out from a great winter and spring. I'm very interested to see how this summer evolves down here in the SW.

There is some nuance to the thing. In recent years all of the offices in the southwest affected by the monsoon decided to define the monsoon period as a specific date range rather than actual monsoon conditions, so that runs June 15 to the end of September if I am remembering right. In the past there was the 55 degree dew point rule, which said that the monsoon arrived in Phoenix or Tucson when you had 3 days of dew points that high or higher (on average). Many in the news will still show the old way of doing things since its more sensible if you ask me. You'll also find "on the street" if people are going to talk about the monsoon down there most will think that anytime you get a few storms during the warm season that its part of the monsoon. Some will even call the storms themselves "monsoons" which is obviously more incorrect. The point I was trying to make is that a true monsoon occurs when the subtropical high lifts north of the area and lower pressure from the intense heat reverses the pressure gradient and winds on a seasonal scale. The current little event you have going on down there is more of what we called a "transition" event, which is more common in the fall. But the idea is that it can temporarily pull moisture north and result in showers and storms but its a different mechanism than the true monsoon pattern. Interestingly enough you can make a good argument that Phoenix doesn't have a true monsoon since it's on the edge of the monsoon circulation with its impacts being irregular and not continuous like you would find a few hundred miles to the southeast. The monsoon has a climatology that creeps up the mtns of Mexico, then into New Mexico, and then gradually moves west into Arizona by early to mid July most years.

Are you still upset that Hitler lost WWII?

Marine layer has deepened once again.

Thanks for your insight. I know this pattern will likely cycle into the later parts of July and Aug which is encouraging for the Monsoon. This mornings AFD out of PHX touches on the southerly flow aiding in the moisture and I quickly assumed that nature may be trying to showcase hints of the Monsoon this year?