What the phrase "Riding out the storm" refere to or mean?

The "storm" refers to hardship or painful times that a person is going through in their life.
"Riding it out" means they just have to keep going until things get better.

So basically it means, waiting for the for the pain, or stress, or the hardship to be over, just like a storm will pass, so will the hardship.

Hope that makes sense.