

Theoretical limit to how hard it can rain - soundsop
http://www.reddit.com/r/askscience/comments/i1zla/is_there_a_theoretical_limit_to_how_hard_it_can/c208i5d

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lutorm
That's not very useful limit.

First, the hottest temperature recorded was probably in some place like Death
Valley, so the humidity was probably very low. Thus there isn't nearly as much
water is the air as indicated by the saturation pressure.

Second, if you somehow did manage to have hot air fully saturated with water
mix with very cold air, the hot air has much higher heat capacity (due to all
the water in it). One cubic meter of -83C air has a mass of roughly 1kg, so a
heat capacity of 1kJ/K. The heat of vaporization of water is about 2000kJ/kg,
so by the time you'd condensed about 70g of that water, the cool air would
have heated up to +55C (and that ignores the heat capacity of the hot air and
the water).

So it's pretty safe to say, yes it's a _limit_ but not a very useful limit as
it is so far above what's physically possible.

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rudyfink
While not close to the theoretical maximum, the observed records are,
nonetheless, stunning.

1 min - 31.2mm (1.23")

60 min - 305mm (12.0")

12 hr - 1.825 m (45.0")

24 hr - 2.467 m (97.1")

72 hr - 3.929 m (154.7")

96 hr - 4.869 m (191.7")

12 month - 26.47 m (1042")

source (<http://wmo.asu.edu/#global>)

Almost all of the records come from La Réunion (
<http://en.wikipedia.org/wiki/R%C3%A9union> ), which is an island straight
east of Madagascar. If you're from the US, think of the Hawaiian islands but
in the Indian Ocean. Significantly, the island has peaks that rise up to 3,070
meters (10,070 ft).

I am guessing large Indian Ocean cyclones get going and then just run slap
into this vertical peak in the middle of the ocean. Then, rain. Rain for
apparently days straight.

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ahi
Straight east of Madagascar.

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rudyfink
fixed

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Groxx
Can there be any non-technical response to this that isn't roughly equivalent
to "Awesome"?

Meh. I love the depth of the answer, and what an awesome visualization :D

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cantbecool
I share your sentiment. The whole waterfall from the sky imagery got me. Eye
opening. Sometimes you can find a gem like that on Reddit. Sometimes.

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Groxx
I think I prefer to get my Reddit filtered. Like this.

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Devilboy
There's a Reddit for that... <http://www.reddit.com/r/bestof/top/>

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pavel_lishin
However, that also tends to promote funny threads, in-jokes, etc.

Still better than the average front page for sure, but don't expect it to be
the reddit of three years ago.

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Will_Price
That would make a great simulation to watch.

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scythe
Alright, we need some fans and a massive heat pump, let's make this happen.

