Unusual Arizona Pre-Monsoon

Deborah in Phoenix asks:

Where is da monsoon? : )

Not far away! The forecasts look reasonably good for some action today, or tomorrow.

Deborah replies:

Ah--I see it. It "Lurketh on the Threshold". Lovely!!!

I reply: One reason I mention tomorrow is that the westerly winds look a little too brisk to bring it across the threshold today, but I may be wrong on this point! You will know in a few hours!

Deborah replies:

There is a mild breeze out there and the humidity is something else for AZ and the sky already is looking hazy. I can't see the horizon for any of that typical buildup though.