Storms described as "apocalyptic" tore across Sydney, Australia, during the afternoon commute on Wednesday, local time, resulting in travel delays, localized flooding and gusty winds. Photos of the thunderstorms flooded social media platforms such as Twitter, where #sydneystorm began to trend.
"It was a typical, warm and sunny late-summer day in Sydney," AccuWeather.com Meteorologist Mark Paquette said. "Convection flared inland and drifted toward the coast and interacted with a bit of a sea breeze and the 'apocalyptic' storms resulted."
Many of the photos shared on social media showed a classic shelf cloud, which often forms at the leading edge of a gust front or outflow boundary from a thunderstorm, or strong winds flowing down and outward from a storm.
The outer part of a shelf cloud is often smoother with a notable rising motion exhibited by tiers or levels, so it looks similar to a shelf. Underneath the smooth part of shelf clouds, it takes on a turbulent, unsettled appearance.
A shelf cloud should be seen as a harbinger of strong winds, so caution should be taken.