loading
City:

Nimbostratus

Nimbostratus (Ns) - the name derives from the Latin nimbus = rain, and stratus = spread out. Nimbostratus is a member of the ten fundamental cloud types (or cloud genera). Although it is classed as a middle-level layer cloud, its base is generally low at 0 to 2 km (0 to 6,500 ft), often very close or even touching the ground. Nimbostratus are also classified as clouds of extreme vertical development.


Nimbostratus are very common clouds in temperate latitudes, forming a dense and extremely extensive grey layer at low altitude. They are thick, dark, amorphous and solid in appearance, often associated with more or less continuous rainfall which makes the cloud base soft and diffuse. Frequently they have ragged edges and small cloud fragments, called scud, developing beneath the main nimbus cloud from recondensation of water saturated air. The Sun is always obscured. Nimbostratus clouds produce dull and gloomy wet days. Precipitation of snow or rain is prolonged and widespread, although not usually heavy and individual small areas may not be producing precipitation at any one moment.

On mountainsides, nimbus clouds often can be seen ascending or descending the slopes as a rainstorm arrives or departs.


Nimbostratus clouds might consist entirely of cloud droplets or raindrops, or of ice crystals and snowflakes. However, the composition of nimbus clouds varies greatly depending on temperature and often they may be mixed with supercooled water droplets and ice crystals present at the same layer.

Extensive layers of nimbus clouds arise through the slow uplift of moist air in a depression, typically at the advancing warm front. Thickening layers of altostratus (As) are frequently preceeding the nimbus cloud as the cloud base lowers towards the surface. Nimbostratus is distinguished from altostratus (As) by its thickness and from altocumulus (Ac) and stratocumulus (Sc) by the fact that they have regular patterns and a well defined cloud base. If the cloud is accompanied by thunder, lightning or hail, then it is d efined as being cumulonimbus.


Varieties of Nimbostratus:
Ns praecipitatio, when precipitation is reaching ground, virga with fall-streaks and pannus, as ragged scud clouds developing between ground surface and cloud base. However, nimbostratus is not subdivided into species, nor does it have very much 'true' varieties. Because of its density, no optical phenomena will appera underneath it. Its just a grey dark blanket.


What do nimbostratus tell about the weather?
Well, firstly nimbostratus are bringing often days of persistent rain or snow. Fall-streaks hanging from the cloud base are heralding imminent rain or snow. Breaking up nimbostratus indicates the passage of a cold front.


Add to social bookmarking:  | more |
A is for Air
Accessory clouds
Advection
Air masses and their sources
Air-mass Thunderstorm
Alpine Glow
Altocumulus
Anticyclone
Atmosphere - Diagram
Aurorae - Northern Lights
Average rainfall over England and Wales
Azores High
Banner Cloud - the peak's flag
Beaufort Scale
Blizzard
British Weather Terms
Brocken Spectre
Bubble High
Burning Time
CAPE - Convective Available Potential Energy
Cap cloud
Cc floccus
Cc lacunosus
Cc stratiformis
Cc undulatus
Central England Temperature
Centres of action
Ci fibratus
Ci radiatus
Ci spissatus
Ci uncinus
Ci vertebratus
Cirrocumulus
Cirrostratus
Cirrus
Clocks go Back from BST to GMT
Cloud classification
Cloud seeding
Cloud species
Cloud streets
Cloud types (genera)
Cloud variety
Clouds - sentry of the sky
Cold low
Comma Cloud
Comma Cloud
Convection
Coriolis effect
Corona
Crepuscular rays
Cut-off low
Dew Point
Dew
Discovery of the Jet Stream
Doppler radar
Drifting snow - blowing snow
Drought
Earth's Atmosphere
Easterly wave - the Hurricane's cradle
El Nino
Föhn (foehn) wind
Föhn wall
Flash Flood
Fog and Mist
Fogbow
Forecasting weather
Frost hollow
Fujita Scale Statistics
Fujita Tornado Scale
Funnel cloud
Genoa Low
Geostationary Satellites
Geostrophic Wind
Glaze and Black Ice
Glory
Grass Minimum Temperature
Gustnado
Hail
Hailstorms in Britain
Highs and Lows and Winds
History of Hurricane Names
Hoar Frost
Humidity
Inversions
Isobars on surface maps
Jack Frost
Jet stream cirrus from space
Katabatic winds
Key to our weather symbols
Lake-effect snow
Latent Heat
Levanter cloud
Millibar and hectopascal
Mirages
Mizzle
NOAA satellites
Nimbostratus
North Atlantic Drift (Gulf Stream)
Polar Orbiting Satellites
Polar low - the arctic hurricane
Precipitation Map
Radiosonde
Rain gauge
Rime
Roll cloud
Rotor cloud
Saffir-Simpson scales
Sc duplicatus
Sc perlucidus
Sc undulatus
Shelf Cloud
Sometimes a bit fishy
Sounding
Southern Oscillation
St. Swithun's Day
Standard Reference Period
Stevenson Screen
Stratocumulus
Stratosphere
Sun pillar
Supercooled clouds
Surface wind
Swell
TORRO
Thermocline
Thunderstorm Probability
Thunderstorms
Tornado Alley
Troposphere
Troposphere - Diagram
UV Index
Ultraviolet radiation
Virga or Fallstreak
What Makes Northern Lights Happen?
What does it mean?
Why Skies are Blue
Why Thunder Rumbles
World Meteorological Organisation (WMO)