This question comes from this post, where I am trying to express the following meaning clearly and concisely.
this is clear but not concise
on a rainy day, Bob is grumpy with a 60 % chance, Bob is happy with a 40 % chance.
is this clear and concise?
on a rainy day, Bob is grumpy with a 60 % chance, happy with 40 %
Thank you for linking to the post where the statement originated. It explains the very odd, and perfectly correct, syntax of (thing occurs) with a (percent) chance.
The most concise you should make the sentence, and still have it readable for humans, is something like :
On a rainy day, Bob is grumpy with a 60 % chance and happy with a 40 % chance.
Adding on to Valkor's answer, the main issue is the word 'with'.
While you can use 'with' to indicate possession, such as ‘a blouse with a white collar’ (Lexico), this sense is normally used for nouns, and not statements such as 'Bob is grumpy'.
Phrased in this way, it sounds like the 60% chance is accompanying 'Bob is grumpy', and not the chance that Bob is grumpy is 60%.
Here are some alternatives which have a similar meaning:
Bob has a 60% chance of being grumpy.
The chance that Bob is grumpy is 60%.
or you can use the construction 'There is' as suggested in a comment:
There is a 60% chance that Bob is grumpy.
