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Comment by falloon | Hacker News Reader

Pedantic cloud enjoyer here, the article should name this a pyrocumulus not pyrocumulonimbus - the nimbus part means 'rain-bearing' in meteorology, fire clouds don't rain.

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Cumulonimbus has been separated from its etymological roots. It now refers to the physics that can produce deep convection, high clouds, and the formation of an anvil shape (along with lightning, etc). The convection that produces a cumulonimbus rain cloud is present in a pyrocumulonimbus cloud. The word isn't wrong.

People need to learn what compound words are.

Well, I was confidently wrong about that. I stand corrected, thanks for the pointers.

Comment threads like these are why I read HN comments.

Thank you for the insights, both of you.

Pyrocumulonimbus [1] appears to be the most extreme version of pyrocumulus [2] which, coincidentally, was observed halfway around the world in Washington State this week [3].

[1]: https://en.wikipedia.org/wiki/Cumulonimbus_flammagenitus

[2]: https://en.wikipedia.org/wiki/Flammagenitus_cloud

[3]: https://www.seattletimes.com/seattle-news/climate-lab/little...

Incorrect. These fires basically create their own weather systems. All that smoke also contains a lot of water in the material that is burning. (That makes sense. They are trees, after all.) When the smoke reaches high enough in the atmosphere the smoke cools and water can precipitate out (rain) and also lightning potentially producing more fires.

To be fair, it's not the article that's the problem. Pyrocumulonimbus is the accepted scientific name: https://en.wikipedia.org/wiki/Cumulonimbus_flammagenitus.

Thanks for the article. However, the article mentions that they might involve precipitation.

Yes, they might. The grandparent comment of this thread in multiple different ways, not just the name.

The term used by the UK Royal Meteorological Society is pyrocumulonimbus: https://www.rmets.org/metmatters/pyrocumulonimbus-clouds

During the press conference describing this the speaker claims they’re working with meteorologists from France Météo supporting the term at 6:30 https://www.dailymotion.com/video/xas3lw2

Technical details in the video link start around 3:34 for those interested

Excuse the French for the non Francophones but trying to be detailed and exacting here on why this isn’t bad journalism to use that term

It rains ash. While it’s a metaphorical use of “rain” it’s physically accurate.

Apparently this cloud can create lightning and its own wind though

it rains hellfire

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