In a 4-quart soup pot, cook bacon over medium-high heat, stirring, until brown and crispy, about 5 minutes. Pour off all but 2 Tbsp. fat.
Add onion, celery and bell pepper and cook, stirring, until softened, 4 to 5 minutes. Add potatoes, corn, thyme, salt and pepper. Stir to combine.
Sprinkle flour over mixture and stir until thickened and fragrant, about 3 minutes.
Slowly pour in broth, stirring constantly until smooth. Add bay leaf; bring to a boil. Reduce heat; simmer until potatoes are tender, 25 minutes.
Remove bay leaf and stir in half-and-half. Cook until warmed through.