Many Canberrans were led to believe snow fell across the capital, but it’s actually a form of hail called ‘graupel’. Photo: Merren Furness, Facebook.
It’s been bitterly cold in Canberra and the surrounds for the last month of spring, with some convinced sleet or snow fell this morning.
But according to Weatherzone meteorologist Jess Miskelly, it was actually something else.
Graupel, a very close cousin to snow, is what we saw fall across Canberra and the surrounding region on Wednesday (16 November).
“When snow forms, it comes together as flakes, whereas hail and graupel are more like pellets,” Ms Miskelly said.
“So while it can appear like snow, it’s not flakes. It’s way different.”
Graupel is a type of hail caused by supercooled water droplets in the atmosphere, which freeze onto snow crystals suspended in the air.
Despite being frozen pellets, they can be quite soft, which also leads to confusion with snow.
While graupel fell in most parts of Canberra, higher elevations saw snow. Photo: Royal Arms Guesthouse Nimmibatel, Facebook.
The atmosphere also plays a role.
“Snow forms in a cold atmosphere, so depending on how cold that’s measured to be tells you the expected elevation it could fall to,” Ms Miskelly said.
“But obviously, we can get hail in summer, so that’s formed under completely different circumstances.”
The snow elevation level for Wednesday was predicted at 1000 metres; however, most Canberra suburbs sit between about 550 and 650 metres above sea level.
Even though Canberra’s official temperature was just 6.6 degrees at 11 am – when the heaviest graupel was recorded – that’s just not cold enough for snow.
Surrounding areas such as Cooma and Nimmibatel are definitely at an elevation where snow fell.
Canberra’s average November maximum is 22.7 degrees, making today’s forecast top of 15 degrees well below average.
Cold fronts aren’t out of the ordinary for this time of year. The coldest November day the capital shivered through was on 11 November 1965 when the mercury hit just 9.1 degrees.
“The cold fronts are managing to get a long way north,” she said.
“We sometimes get the cold air, but there’s so much moisture as well.”
While things are expected to warm up over the weekend, another wintry snap is possible.
“It looks like a similar set-up come Monday,” Ms Miskelly said.
So watch this space.
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