Incredibly rare mammatus clouds over NYC right now!

As I type this, there are mammatus clouds over NYC. These are fairly rare to begin with, especially in this area. They typically form underneath the anvil of a thunderstorm, and are immensely rare in the absence of thunderstorms. If I had to guess, these are likely associated with the passage of the cold front that brought the rain to our area. My friend John Homenuk (great twitter follow for local weather info - @jhomenuk; see other thread about his winter weather forecast) snapped an amazing picture over the WTC. My view wasn’t quite as good, but I was able to see them above the Empire State Building from Madison Square Park. I can’t stress how rare this is, given the time of year and atmospheric conditions. 

What makes mammatus clouds especially cool is we don't really know how/why they form. They take the shape of little bulbous puffs underneath high cirrus clouds and given their geometry often become brilliantly illuminated as the sun strikes them.


Back in the 80's when I lived in Austin, we had a spectacular display of mammatus clouds one day. The whole city tuned in to the nightly news to learn about this amazing phenomenon. The weatherman was beside himself with excitement. He described the conditions that cause these cloud formations. He then said "You can probably guess the origins of the word "mammatus," and then froze, realizing he couldn't possibly say "breast" on live TV. He resumed after a pause ... "Cottonballs! The origin of the word is cottonballs!" Poor guy. 

Sadly, I missed today's clouds (too cold to go outside!) but I noticed an unusual pink light at sunset. Wish I'd looked.


They were really cool. Thanks for the info on what they were. 


Very cool! If I have ever seen them, I didn't know what they were called. I love you weather nuts. grin


This is good to know, thank you. 

I overlooked the time stamp on your post and ran to the window to look. ;^)



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