Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until crisp, 10 to 12 minutes. Drain bacon slices on paper towels and chop when cool enough to handle.

Meanwhile, bring a large pot of lightly salted water to a boil; cook rotini at a boil until tender yet firm to the bite, about 8 minutes.

While pasta is cooking, place chopped avocado in a small bowl. Drizzle with lemon juice and toss gently to coat.

Rinse pasta under cool water and drain; transfer to a large bowl. Add chopped bacon, salad dressing, Monterey Jack cheese, green onions, black olives, and tomatoes; stir to combine. Gently stir in avocados. Place in the refrigerator to chill, 8 hours to overnight.