Here is a photo showing a few of the fruit. However there are about 50 smaller fruit on the entire tree.

Your tree very likely has many flower buds still unopened so may bloom more in spring. But you are in a very atypical situation for most of us. Your tree may not get enough chilling for the remaining flower buds to open at normal time in a month or two. So I'd leave the current fruit and see what it does. You may get two crops, a very extended light harvest, or nothing at all.

Thank you fruitnut. I will leave as is and see what happens.

My 'Beauty' plum does this almost every year, but not to the extent that yours has done. I just remove the immature fruits because nothing ever comes from it. The fruit never matures. Seemed like a waste of energy for the tree to try and ripen them when it should be dormant.

Agree w/ mrclint.

The first time my Santa Rosa plum set fruit in fall, the fruits never matured.
The 2nd time it set fruit in the fall, I removed all fruit I could reach.
In both instances, the tree later set and matured a normal crop on time.

Jean,
who gardened for 30-some years in Long Beach, CA

Thank you mrclint and thank you Jean. I think I will go ahead and remove the fruit now. Appreciat all the replies!