Apple fans’ alarms are ringing all over the country right now as Apple’s flagship iPhone 5s finally becomes available to purchase online. The company curiously decided against making the 5s available for preorder alongside the iPhone 5c last week, though numerous reports including a BGR exclusive point to severe supply constraints as the likely reason. The wait is finally over, however, and the iPhone 5s can finally be bought online on Apple’s website or on some carrier websites including Verizon Wireless and AT&T. Considering how tight inventory is expected to be, odds are good that we’re looking at a couple of hours of availability at most before we see those delivery dates begin to slip back. So, those hoping to get their hands on an iPhone 5s sometime soon, and who have no interest in battling through lines come daylight, should probably head over to Apple’s website right away.