Author Topic: Formula for estimating cloud base. Explanation please  (Read 1270 times)

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Offline attherubicon

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Formula for estimating cloud base. Explanation please
« on: March 28, 2021, 09:38:29 PM »
Iv see this formula in several places for estimating the height of cloud bases:

CB ≈ (T - Td)*1000/4.4

Im puzzled by the 4.4. I would expect a number for the dry adiabatic lapse rate, but Not 4.4

Offline sky_watcher

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Re: Formula for estimating cloud base. Explanation please
« Reply #1 on: March 28, 2021, 09:55:31 PM »
Iv see this formula in several places for estimating the height of cloud bases:

CB ≈ (T - Td)*1000/4.4

Im puzzled by the 4.4. I would expect a number for the dry adiabatic lapse rate, but Not 4.4
From the Cloud Base Calculator site:

The rate at which air cools is estimated at 5.4F per 1000 feet of altitude. The dew point decreases slower - at about 1.0F per 1000 feet. That means that per 1000 feet, the spread decreases by 4.4F.
The more a man knows, the more willing he is to learn. The less a man knows, the more positive he is that he knows everything... ― Robert G. Ingersoll

Offline attherubicon

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Re: Formula for estimating cloud base. Explanation please
« Reply #2 on: March 28, 2021, 09:56:46 PM »
Thank you.

Offline CW2274

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Re: Formula for estimating cloud base. Explanation please
« Reply #3 on: March 28, 2021, 10:16:25 PM »
Iv see this formula in several places for estimating the height of cloud bases:

CB ≈ (T - Td)*1000/4.4

Im puzzled by the 4.4. I would expect a number for the dry adiabatic lapse rate, but Not 4.4
The rate at which air cools is estimated at 5.4F per 1000 feet of altitude.
Just as an FYI, known as "standard lapse rate".

 

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