Agree with DD, those look like trichomes to me. Some strains are super frosty. Once you have a jewellers loupe or even a strong magnifying glass you should be able to see the mushroom shaped trichomes.
I didn’t realize WPM would glow under a blacklight - that is really cool, I am going to get a blacklight flashlight as well. With that said, I read an article recently that said WPM is a fan of warm humid air but doesn’t like rain (more of a summer problem than a fall problem). Not sure how warm SF is this time of year but since you are outdoors it may be too cool now for WPM to really take hold (would love to hear if anyone has experienced different). Bud rot (botrytis) likes cool wet weather, which makes it the bigger problem where I am this time of year, with temps mostly 10-20C and more frequent rain.
EDIT Click through on the second pic to the full size and expand it - you can clearly see the bud is covered in trichomes.