1) That is where the greatest density of particulate matter is.
2) That is where the greatest density of large water / ice droplets are.
A thunder cloud, or Cumulonimbus cloud, looks like a massive, tall, white puffy cloud with an anvil shaped top and a very dark grey base.
The wall cloud is a large section of cloud extending down from the base of a thunderstorm. The wall cloud marke the strongest part of the mesocyclone, which is the rotating updraft that can produce a tornado. A funnel cloud or tornado usually extends from the base of a wall cloud.
The funnel cloud.
Many cloud types can lead to a gray sky. Stratus is one of the more common ones.
Wall cloud.
A thunder cloud, or Cumulonimbus cloud, looks like a massive, tall, white puffy cloud with an anvil shaped top and a very dark grey base.
A grey, miserable rain cloud.
The Grey Cloud - 2007 is rated/received certificates of: Australia:M
Blue grey, dark grey, warm grey, cool grey, cloud grey, silver.
No, the wall cloud is a lowered section of the cloud base from which a tornado or funnel cloud descends. The dark cloud at the base of a tornado is called the debris cloud.
Cumulonimbus cloud's colour depends on the conditions, time and your location. In broad daylight, with the sun shining on them they are usually white, like all clouds in daylight. The base of the cloud is dark grey because of the thick cloud blocking the sun. Depending on the cloud thickness, the underside of a cumulonimbus can even be black. When there is a lot of hail and ice crystals in the cloud, it can take on a green or turquoise appearance. In the sunset, the cloud can appear brown, orange or red. At dusk, the cloud can appear light blue, and at night, it is usually hard to see untill lightning illuminates it.
I would expect rain to be formed from a dark grey cloud.
grey clouds
Nimbus
a grey one
At the moment Sunday 28th November... 21:00 - Fog (monday) 00:00 - Grey cloud 03:00 - Grey cloud 06:00 - Snow 09:00 - White cloud 12:00 - White cloud 15:00 - partly sunny 18:00 - Grey cloud Monday night - Snow
== == == == They are very large and with very undefined edges. And they are a distinct grey tone.