10

Its always been cool to be climbing a mountain and look down, and realize that you are high enough that there are clouds below you.

Here are some pictures from Wikipedia of what this looks like.

I would think that the weather would have a great deal to do with when this happens, what are good indicators or conditions that would create situations like this?

  • Cold air temperature, little wind, and high humidity. This will lead to fog, which will give you a great view. – Burhan Khalid Jan 3 '17 at 5:17
  • Google "cloud inversion" and you will find lots of info, like ukhillwalking.com/articles/page.php?id=7888 – Qwerky Jan 3 '17 at 12:33
  • With morning mist in a lot of places it's possible even at comparatively low altitudes. I've seen it in the Lake District, and from the Balcombe viaduct. – pjc50 Jan 3 '17 at 15:50
  • If you're actually just looking for general indicators: have a glance at some webcams located on mountain tops in the area (at least in Switzerland there must be hundreds). --> You quickly see if it's worth taking a hike to escape the cloudy valley floor and get some sun. :) – fgysin reinstate Monica Jan 5 '17 at 13:31
14

That phenonmon is called a cloud inversion. It happens in mountainous areas when a layer of warm moist air passes over cold valley floor. So initially the valley is full of cold air:

\            /
 \   cold   /
  \        /
   \______/

In certain circumstances (an approaching warm front) a layer of warm moist air will pass into the valley and will be forced above the cold air (warm air rises and is less dense, etc)

\    warm    /
 \ -------  /
  \  cold  /
   \______/

The valley sides and the warm air trap the cold in the valley bottom. Where the warm and cold air touch water is condensed from the warm air to form clouds (---). The warm air acts as a "cap" preventing the cold from escaping (Capping inversion)

what are good indicators or conditions that would create situations like this?

Your looking for a warm front meeting a cold air mass (high pressure in winter) in a mountainous area. Strong winds will "mix" the air masses, so ideally it should be calm.

This typically happen around dawn and tend to burn off as the valley bottom is heated, though they can last for long periods of time if the conditions are right. The larger the tempaterature difference (between the cold and the warm masses) the better chance of this happening so look for a warm front where the temperature infront of it, is a lot colder than that behind it (all warm fronts have this to a degree)

BTW the mountains don't have to be particualry high, this does happen at quite low levels, I've seen it on hills no more than a couple of hundred feet.

  • 1
    You can have low level clouds without a temperature inversion. And can have a temperature inversion without clouds. It is not limited to mountains - fly up above the clouds is very common. – paparazzo Jan 3 '17 at 20:09
  • Another cause is (I think) humidity. Used to be fairly common in the summers where I grew up: river valleys running through low hills, fog would collect in the valleys on humid nights while it would be clear on the hills. – jamesqf Jan 3 '17 at 21:37
7

There are various factors to lead you being above the clouds.

Mainly what you want to do is to be on top of a mountain during Thermal inversion.

From wikipedia:

In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude.

6

Many clouds are below mountain level

Common Cloud Names, Shapes, and Altitudes

The lower are typically cooling of air and not limited to an inversion

Stratocumulus Clouds (“The low, puffy layers”) can typically be detected from the ground
That is a climb safe cloud

2

Maybe the mountain is just very tall. Haleakalā has a sunrise tour where you can see that every day.

-2

It is called fog, and you are standing higher then it is thick.

Clouds can form at many different altitudes. They can be as high as 12 miles above sea level or as low as the ground. Fog is a kind of cloud that touches the ground.

Source

  • It's not always (or even usually) fog. I've had hikes where the trailhead had unlimited horizontal visibility, the summit had unlimited visibility, and you couldn't see one from the other due to clouds. – Mark Jan 4 '17 at 0:13
  • The definition of fog is a cloud that is at or near the surface of the earth. All fog is cloud, but not all clouds are fog. All people are mammals but not all mammals are people. – James Jenkins Jan 4 '17 at 11:08

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