Exempel på altostratus

• Often, when an altostratus cloud thickens and descends into lower altitudes, it will become nimbostratus.

• This cloud typically forms from altostratus in the middle altitude range, but it tends to thicken into the low altitude range during precipitation.

• The variety "undulatus" (having a wavy undulating base) can occur with any clouds of the species stratiformis or lenticularis, and with altostratus.

• Altostratus and nimbostratus clouds always have this physical appearance without significant variation or deviation and, therefore, do not need to be subdivided into species.

• They also can occur under altostratus cloud preceding a warm or occluded front, when cumulus usually lose vertical development as the sun's heat decreases.

• The altostratus velum cloud appears dark in comparison to its parent cloud, and can persist even after the cumulonimbus has disintegrated.

• A further thickening of the altostratus is often accompanied by virga and the arrival of precipitation is imminent.

• However, only two are seen with altostratus and stratus nebulosus whose uniform structures prevent the formation of a perlucidus variety.

• The best-known is cumulonimbus with mammatus, but the mamma feature is also seen occasionally with cirrus, cirrocumulus, altocumulus, altostratus, and stratocumulus.

• Altostratus is usually composed of water droplets but may be mixed with ice crystals at higher altitudes.

• These include middle-tage layers of "altocumulus" and "altostratus" as well as low "stratocumulus", and "stratus".

• If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.

• The sun can be seen through thin altostratus, but thicker layers can be quite opaque.

• Fractonimbus exist only under precipitation clouds (such as nimbostratus, altostratus or cumulonimbus), and don't produce precipitation themselves.

• High altostratus clouds and night flying conditions prevented him from making any visual contact.