Apple has nearly caught up with demand for iPhone 5

Gene Munster and his team at Piper Jaffray have continued their nightly checks of 100 Apple Stores. They found that supply of AT&T and Verizon models has "significantly improved," while Sprint units remain readily available.

"As we get closer to the holiday, we believe consumers will likely have the ability to walk into an Apple Store and walk out with an iPhone 5 within the next two weeks," Munster said.

His checks of Apple's stores found "dramatic improvements in availability," as Tuesday night the AT&T model was available at 82 percent of stores and the Verizon model at 72 percent of stores. The Sprint iPhone 5 was also in stock at 92 percent of Apple Stores.

Signs of improved supply come as Apple this week changed its online store to advertise two-week shipping times for the iPhone 5. Apple's estimated shipping times for products are often seen as a sign of how well the company is able to keep up with demand.

Availability of the AT&T and Verizon iPhone 5 models was severely constrained earlier this month, but Apple has been gradually catching up in recent weeks.

Apple is believed to have encountered a number of quality control issues with assembly of the iPhone 5 when the device first launched. But information from the company's supply chain found that capacity was steadily improving as Apple's partners acclimated to production of the redesigned device.