The northeast of the United States is in the midst of a blizzard, which could bring a potentially historic amount of snow to New York City. But earlier today, before temperatures drop and the snow covers everything, these large, star-shaped snowflakes were spotted all over the city.
Weather.com meteorologist Chris Dolce explained that all of these sightings are due to the specific way they've fallen:
If snowflakes stay separated from each other like you see in these photos, and if you look closely enough, you can sometimes see the structure of snowflakes with your naked eye.
There are many different types of crystal patterns and these star-shaped snowflakes are just one example. The dendrite, a star-shape with varying patterns, is the most common shape of a snowflake.
An excellent primer on all the various shapes snowflakes can take is available from Caltech physics professor Kenneth Libbrecht, who has a whole website devoted to them. Based on his description, we're also seeing "rimed crystals" in these photos, which Libbrecht describes as:
Clouds are made of countless water droplets, and sometimes these droplets collide with and stick to snow crystals. The frozen droplets are called rime. All the different types of snow crystals can be found decorated with rime. When the coverage is especially heavy, so that the assembly looks like a tiny snowball, the result is called graupel.
Additional reporting by Mika McKinnon