Author Topic: What is "heavy rain"?  (Read 844 times)

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Offline dwaldmann

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What is "heavy rain"?
« on: September 19, 2022, 08:13:10 PM »
Wondering if my new Davis Instruments Aero Cone is giving false readings or if the old one just never properly accounted for our wind conditions here. I don't recall (and don't have access to historical records) what previous amounts were, but last week I got over 3" rain rate and today 5.76". Is that even possible?

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Offline CW2274

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Re: What is "heavy rain"?
« Reply #1 on: September 19, 2022, 08:34:10 PM »
Very possible. Tropical systems in particular will easily dump this much rain.

Offline Mattk

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Re: What is "heavy rain"?
« Reply #2 on: September 19, 2022, 09:15:19 PM »
"Heavy rain" is typically over 2mm /minute but certainly possible to have higher intensity periods in between "heavy rain" which is what Davis measures being the rate the bucket is tipping as opposed to total rain recorded over the hour   

Offline hofpwx

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Re: What is "heavy rain"?
« Reply #3 on: September 20, 2022, 12:54:55 AM »
Likewise, what is “raining cats and dogs”?




Offline CW2274

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Re: What is "heavy rain"?
« Reply #4 on: September 20, 2022, 02:19:28 AM »
Likewise, what is “raining cats and dogs”?
It's Davis's attempt at weather humor. When the rain rate reaches, I believe, 0.30" per hour, this pops up in the ticker display.

Offline hofpwx

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Re: What is "heavy rain"?
« Reply #5 on: September 23, 2022, 01:13:02 PM »
Likewise, what is “raining cats and dogs”?
It's Davis's attempt at weather humor. When the rain rate reaches, I believe, 0.30" per hour, this pops up in the ticker display.


I figured an attempt at WXwit but was also a bit curious about the threshold. Thanks!


Offline saratogaWX

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Re: What is "heavy rain"?
« Reply #6 on: September 23, 2022, 05:59:09 PM »
What I've used in the template set is
Quote
    Light rain — rate is < 2.5 mm (0.098 in) per hour
    Moderate rain — rate is between 2.5 mm (0.098 in) - 7.6 mm (0.30 in) or 10 mm (0.39 in) per hour
    Heavy rain — rate is > 7.6 mm (0.30 in) per hour, or between 10 mm (0.39 in) and 50 mm (2.0 in) per hour
    Violent rain — rate is > 50 mm (2.0 in) per hour
I think I'd used a Davis doc (in 2011) for those values. 
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Offline CW2274

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Re: What is "heavy rain"?
« Reply #7 on: September 23, 2022, 06:56:46 PM »
Violent rain? Seems a touch overly dramatic to me. I've always liked "toad choking"..

Offline saratogaWX

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Re: What is "heavy rain"?
« Reply #8 on: September 23, 2022, 07:13:35 PM »
Ahh.. dug into the past.. I'd used the AMS definitions https://glossary.ametsoc.org/wiki/Rain (light,moderate,heavy) and the WMO https://community.wmo.int/activity-areas/aviation/hazards/precipitation (violent).
Ken True/Saratoga, CA, USA main site: saratoga-weather.org
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Offline ocala

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Re: What is "heavy rain"?
« Reply #9 on: September 24, 2022, 10:45:03 AM »
Wondering if my new Davis Instruments Aero Cone is giving false readings or if the old one just never properly accounted for our wind conditions here. I don't recall (and don't have access to historical records) what previous amounts were, but last week I got over 3" rain rate and today 5.76". Is that even possible?

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Happens all the time. Recently almost 10 inches.
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The blues had a baby and they named it Rock & Roll