Durban folk had their heads turned skywards yesterday to witness the rare Morning Glory clouds that streaked across the city.
This unusual cloud formation is not clearly understood because it occurs so infrequently, and there are many different hypothesises as to how they occur.
Mduduzi Mthembu, of the Durban weather office, described them as “rolling clouds” and said that this phenomenon occurred before a cold front, and especially in summer.
“When cold, denser air enters a warm environment at a high speed, the warm air lifts and forms clouds in this manner,” said Mthembu.
He added that, even though there was a cold front moving in, there was no need to unpack the winter woollies.
“We are in summer now. There may be some light drizzle tomorrow, but it is clear for the rest of the week.
“We will see reactions like this because the air is so much warmer than it was a month ago when similar cold fronts came in.”
The thunderstorm that occurred yesterday afternoon was a “typical summer thunderstorm” that had moved from the interior during the day to the coast in the afternoon, said Mthembu.
The Morning Glory cloud is sometimes seen in central America, over the English Channel, in Germany, Russia, Australia and Brazil.
Many people in Durban took to social media network Twitter to share their impressions of the occurrence, so much so that #rollcloud was quickly trending in South Africa.
@GlenPike1 tweeted: “This is how the clouds roll in #durban before the storm.”
@shEeeeevvvVvvy tweeted: “Crazy wind in Durban 2day; and freaky looking clouds too!!!” and @MsJetSetterTaya thought they were “Strange but beautiful”.