The availability of the 13-inch MacBook Air has started to dwindle incidentally a few weeks before Apple's WWDC 2013 in June and prior to the launch of the new Intel Haswell processors. The tightening supply has triggered rumors that a possible refresh of the MacBook Air range is imminent.

Apple has not announced any update to its hardware lineup since October 2012 and last April, analysts said that consumers can expect new products to be launched during the annual developer conference of the company.

According to an inventory check reported on AppleInsider, the popular Apple ultraportable with a 13-inch display, 256GB solid state drive, and a 1.8GHz processor is out of stock at retailers such as MacMall, MacConnection, B&H and Amazon.

The shortage does not mean a lot since consumers can still purchase the thin-framed MacBook from the official online and retail stores of Apple. However, consumers might want to wait for a bit if they want to get the best value for their money since there are signs that better MacBook Air units are on the way. Analysts noted that prior to a product refresh, supplies of Apple products start to thin out simultaneously at different retailers.

Apple has a very good command of its own supply chain. In a report that was published on The Atlantic last year, the technology giant can turn over its whole inventory in just five days. The company's supply chain is that efficient and it also gives experts hints when Apple is planning to remove the old units from the shelves as the new product enters the market.

Aside from getting the next-generation Haswell processors under its frame, the new MacBook Air might get a Retina display that will put it at par in terms of screen resolution with the high-end MacBook Pro. The use of the high-resolution display has its downside too, since it will bring the price of the notebook up. A more expensive entry-level notebook at this point, will make the brand struggle a bit especially when there is still a high demand for traditional displays that are more affordable than high-resolution screens.

Come the WWDC this June, Apple fans can expect the announcement of the refreshed MacBook Air and also the updated Mac OS.