Partial bloom sounds right.
It seems like there are 2 factors that stimulate bloom, one is length of time / # of chill hours, but another seems to be "shock" (number of degree difference from one day to the next). Going from highs in the high 80's to a sudden drop into the low 50's (high 40's with wind chill?) over a < 24 hour period is a big slap in the face. A more gradual decline in temps has less of an effect... in my experience at least.
I've also seen cold sensitive trees crash and die with lows well above temps that would normally kill them, due to the shock of a quick drop. When plants have a chance to acclimate, the shock is much less.
It’s enough to ignite easily triggered varieties like Rosigold, Dwarf Hawaiian, Rosa and Edward to a full bloom if they haven’t started already but it isn’t enough to stimulate a full bloom on most other cultivars, particularly when the highs are going right back into the mid-80s over the weekend/early part of next week.
More likely to see some partial bloom on a lot of stuff. A longer cold spell spanning a week + would do a lot more. 2 weeks of nighttime temps below 60F is ideal.
Yes there is a shock affect. Temps below 50 F, like which we’re experiencing now, tend to produce a better bloom response as well compared to 50s weather.
A number of trees have recently flushed growth due to the warm fall temps and some are even finishing growth flushes right now. With the exception of certain cultivars ( Rosa, Pim Sen Mun and Ah Ping being a couple examples at our location), “young” , more recent growth will need a couple more months to have a floral response to a cold front.
Hopefully we can avoid extended periods of highs in the 80s and get more lows in the 50s or low 60s, rather than the 70s that we’ve seen much of the last few winters. A complete bloom makes things so much easier for growers like me than the sporadic multiple blooms like last year.