![emoticon5 :emoticon5:](./images/smilies/emoticon5.gif)
http://www.youtube.com/watch?v=436xSvcRjOc
Let me think for a while escreveu:É uma nuvem.
Wallace escreveu:O que propícia a formação delas, sabe dizer? Dei uma olhada pra ver se achava algo e não tive sucesso!
A roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud.