Why the sky turned green over Brisbane
It's unusual for an outbreak of severe thunderstorms to hit southeast Queensland in May. It's also unusual for the sky to be green. But on Wednesday, both happened.
An upper-level low pressure system interacting with a relatively warm and humid air mass produced a number of intense thunderstorms over southeast Queensland and far northeast NSW on Wednesday.
The storms initially developed inland before moving towards the coast and by 4pm, an ominous line of storms was approaching Brisbane from the west.
Image: Lightning strikes detected within 150 km of Brisbane between 4pm and 8pm on Wednesday.
There were about 71,000 lighting strikes detected within a 150 km radius of Brisbane between 4pm and 8pm on Wednesday. Around 5,400 of these were cloud-to-ground strikes, while the rest occurred within or between clouds.
But while the storms produced copious lightning in the Brisbane area and delivered 25mm of rain in under one hour in the city, the storm's green-coloured clouds were arguably the most impressive feature.
Thunderstorm clouds can take on a range of colours as the water and ice they contain scatters light.
When an intense thunderstorm containing large quantities of rain and hail occurs while the sun is low in the sky, the combination of red or orange light in the atmosphere and the light being scattered by the storm itself can produce a distinct green hue in the storm cloud.
Because this phenomenon requires lots of rain and hail to be present in the storm, it's usually only seen when storms are mature and intense.
#Brisbane going green as severe #storms moved across SEQLD this evening.
— Justin Noonan (@NoonanJustin) May 12, 2021
Not quite the epic shot I was after, but I'll take it!#StormHour #queensland #bnestorm #Lightning #WeatherUpdate #thunderstorm @BOM_Qld pic.twitter.com/4weLGilaeR
Wednesday's thunderstorms were certainly intense and severe, with reports of 5 cm hail to the west of Brisbane during the afternoon.
Next time you see green storm clouds in the sky, it would be a good idea to find some shelter.