Frontal cirrostratus is a precursor to rain or snow if it thickens into mid-level altostratus and eventually nimbostratus as the weather front moves closer to the observer.
22.
The exceptions include altostratus that has varieties but no species, towering cumulus and cumulonimbus that have species but no varieties, and nimbostratus has no species or varieties.
23.
Stratiform clouds of the genus altostratus form when a large convectively stable airmass is lifted to condensation in the middle �tage of the troposphere, usually along a frontal system.
24.
In 1840, German meteorologist Ludwig Kaemtz added Middle clouds over Santa Clarita, CA . Altocumulus floccus producing virga near top and middle of image merging into altostratus translucidus near horizon.
25.
:Altostratus is a mid-level opaque or translucent stratiform or non-convective veil of grey / blue-grey cloud that often forms along warm fronts and around low-pressure areas.
26.
It is sometimes seen with the fibratus and uncinus species of cirrus, the stratiformis species of altocumulus and stratocumulus, the mediocris and sometimes humilis species of cumulus, and with the genus altostratus.
27.
Though some snow showers and flurries will also develop over the northern Appalachians, only broken areas of high cirrus and mid-level altostratus clouds will stream east of the Appalachians, arriving during the day over the Northeast Seaboard.
28.
Farther north, some of the mid-to upper-level moisture associated with Tropical Storm Dennis will stream inland into southeast Pennsylvania, New Jersey, and, perhaps parts of southeast New York, mainly in the form of cirrus and altostratus clouds.
29.
The weather conditions at the time of the accident were " dark night due to 7 / 8 ( broken ) stratocumulus at and to 8 / 8 coverage ( overcast ) by altostratus at . " According to the Brazilian Air Ministry, the weather conditions did not contribute to the accident.
