Update 2:38PM ET: The FEMA test Presidential Alert warning successfully out at 2:18PM ET to phones across the country, right on schedule. As expected, the alert followed the existing emergency alert systems on existing smartphones, with the regular tone — although the Presidential Alert heading is new.
According to FEMA’s alert, “Some cell phones will receive the message; others will not. No action is required.” — so if for some reason, you didn’t get the notification there’s no need to worry. Here’s what it looks like, though, if you’re curious.