Looking on the internet deeply has found these results:

out of the blue is the most popular phrase on the web.

suddenly 1343,000,000 results on the web	out of the blue 125,270,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
And then something terrible happened: it suddenly grew. We suddenly have highest lab priority. My room keeps changing suddenly into a different room... Suppose the treadmills broke or stopped suddenly . Nobody smiles in Russia unless they suddenly laugh. But suddenly, life gets sweeter. I woke suddenly with a pain. And then, suddenly, increasingly strange behaviour.	Because he came out of the blue with the presents... Then out of the blue one day, I get a phone call, anonymous voice, pointing me right to her killer. Now, the Wolves game, this money my boss promises me, out of the blue. Suddenly out of the blue, everybody would start fighting with each other. Stephanie called me out of the blue yesterday morning. She calls me out of the blue about some guy who was scaring her. Maeve said it started out of the blue. I mean, just change careers out of the blue.

suddenly

1343,000,000 results on the web

out of the blue

125,270,000,000 results on the web

More popular!

Because he came out of the blue with the presents...
Then out of the blue one day, I get a phone call, anonymous voice, pointing me right to her killer.
Now, the Wolves game, this money my boss promises me, out of the blue.
Suddenly out of the blue, everybody would start fighting with each other.
Stephanie called me out of the blue yesterday morning.
She calls me out of the blue about some guy who was scaring her.
Maeve said it started out of the blue.
I mean, just change careers out of the blue.