Manuscript Preparation, Copyediting, and Proofreading
Q. When is a line space in text (pause) used?
A. A blank line usually signals any break that is stronger than a paragraph but not strong enough to warrant a subhead. In novels and other creative works, such breaks may signal a new narrative voice or a change of location or a leap in time (either forward or backward). There’s no limit to how they can be used, but a good editor will point out breaks that seem arbitrary or distracting. You will also need to be prepared for the fact that a blank line occurring at the end of a page may not read as a break; asterisks or a similar device may be needed. See CMOS 1.58.