Who Is Drier?

[Bill O]

Here's a quiz (meteorologists need not respond).

Out of these two locations and given conditions (from today), who has less water in the atmosphere?

Mount Washington (4am):
Temp: -24F
Dewpoint: -24F
Relative Humidity: 100%
Conditions: Freezing Fog

Death Valley (4pm)
Temp: 61F
Dewpoint: 35F
Relative Humidity: 38%
Conditions: Clear

[inthebeginning]

Here's a quiz (meteorologists need not respond).

Out of these two locations and given conditions (from today), who has less water in the atmosphere?

Mount Washington (4am):
Temp: -24F
Dewpoint: -24F
Relative Humidity: 100%
Conditions: Freezing Fog

Death Valley (4pm)
Temp: 61F
Dewpoint: 35F
Relative Humidity: 38%
Conditions: Clear

This has got to be easier than it appears. As I understand it, Relative Humidity is the amount of water available in the atmosphere. Just because KMWN was at 100% and only 38% at Death Valley, the temp certainly has something to do with it...and the altitude

I am going to say Mt. Washington had less water in the atmosphere in the above reports.

That's my final answer.

[Snow Miser]

Here's a quiz (meteorologists need not respond).

Out of these two locations and given conditions (from today), who has less water in the atmosphere?

Mount Washington (4am):
Temp: -24F
Dewpoint: -24F
Relative Humidity: 100%
Conditions: Freezing Fog

Death Valley (4pm)
Temp: 61F
Dewpoint: 35F
Relative Humidity: 38%
Conditions: Clear

Mount Washington for sure. Even with 100 % relative humidity, at -24F, there must be next to no water in the air.

[Patrad Fischroy]

Yes, at that temperature, all it takes are 3 or 4 molecules of water to get to saturation point.

[sdways01]

Without even knowing much about that part of weather, I am figuring that fact that this question is posted on this particular forum alone means that Mt. Washington had less water in the atmosphere.

[Brad]

Yes, it is an obvious trick question. So, why is the answer Mt Washington?

[Bill O]

Without even knowing much about that part of weather, I am figuring that fact that this question is posted on this particular forum alone means that Mt. Washington had less water in the atmosphere.

I like that reasoning...and, of course, you are all correct.

The real measure of moisture in the atmosphere is dewpoint, not relative humidity. As the name implies, relative humidity is just that, relative. The lower the dewpoint the drier the atmosphere. The next observation the summit broke out of the clouds and the dewpoint dropped down to -35F.

[Brad]

Okay, how about a help on what dewpoint really means.

[Snow Miser]

I think it's basically the temperature at which the air cannot hold anymore moisture, and it begins to condense.

[Bill O]

I think it's basically the temperature at which the air cannot hold anymore moisture, and it begins to condense.

That's a great answer. The typical meteorologist would give you a four paragraph explanation that just leaves you more confused.

Another way to look at it. It's the temperature your cold glass needs to be to get condensation on it. That's why in the summer you get water on the outside of a cold drink, but not in the winter.