Monsoon coming- can I boost blossoming?

[Tracydr]

Our AZ rains and monsoon is predicted to hit in about one week. They're predicting 40% chance of rain next Sunday and Monday. We'll be having awful heat for the next week, which is what brings in the monsoon rains. Last year, I noticed some increased blossoming and fruit set when the monsoons hit.
My tomatoes look amazingly healthy right now and I'm keeping them under a shade cover. Just wondering if there is something I could give them this week that could possibly bring on a little more blossoms? I know I will get a lot of loss me drop from the heat but if I even get a few breaks in the weather I may get some more fruit set.
They haven't had any recent feedings of kelp or fish emulsion so would now be a good time to feed them? It's probably been good 45-60 days since their last feeding.