Clouds

Altostratus is a mid-level cloud genus characterized by a uniform, gray or blue-gray sheet that often covers the entire sky, producing a diffuse appearance and sometimes obscuring the sun.

Stratus is a low-level cloud genus characterized by uniform, grayish layers that often cover the entire sky, creating overcast conditions with a featureless, sheet-like appearance.

Arcus is a striking accessory cloud type characterized by its low, horizontal, and elongated form, often appearing as dramatic shelf or roll clouds at the leading edge of thunderstorms.

Cirrus clouds are high-altitude, thin, wispy clouds composed predominantly of ice crystals, often appearing as delicate white streaks or curls in the upper troposphere.

Stratocumulus is a low-level cloud genus characterized by large, rounded masses or rolls that often form a widespread, lumpy layer across the sky, typically gray or whitish with darker shading underneath.

Cumulus clouds are dense, white, and puffy formations with sharply defined flat bases and rounded tops, commonly seen as fair-weather clouds but capable of growing into towering, precipitation-producing structures.

A contrail, short for "condensation trail," is a thin, linear cloud formed by aircraft engine exhaust or pressure changes at high altitudes, resembling cirrus clouds in appearance.

Nimbostratus is a thick, dark, and diffuse low- to mid-level cloud layer known for producing persistent, steady precipitation and often covering the sky in a uniform gray sheet that obscures the sun.

Fog is a ground-level cloud, appearing as a uniform, grayish veil that reduces visibility to less than one kilometer, effectively cloaking the landscape in mist.

Cumulus mediocris is a species of cumulus cloud marked by moderate vertical development, recognizable by its well-defined, puffy, cauliflower-like tops and flat bases, signaling atmospheric instability that may precede further convective growth.

Fractus is a species of cloud recognized by its ragged, irregular fragments that appear as torn or shredded pieces beneath or near larger cloud formations.

Cirrocumulus is a high-level cloud genus composed of small, white, patchy cloudlets arranged in delicate, rippled patterns often described as a "mackerel sky."

Cumulus fractus is a species of cumulus cloud recognized by its ragged, fragmented, and wispy appearance, often resembling torn shreds drifting at low altitudes.

Stratus nebulosus is a low-level cloud species defined by its uniform, featureless gray layer that often resembles fog and obscures the sky with a continuous, diffuse sheet.

Stratocumulus stratiformis is a widespread low-level cloud species forming extensive, layered sheets or patches with relatively uniform bases and moderate vertical thickness, often covering large portions of the sky in gray or whitish tones.

A shelf cloud is a broad, horizontal, wedge-shaped accessory cloud that forms at the leading edge of thunderstorm outflow boundaries, signaling the approach of severe weather.

Altostratus translucidus is a mid-level cloud variety characterized by its thin, semi-transparent sheet-like layer that allows the sun or moon to be seen as a diffuse bright spot through a uniform grey or bluish-grey veil.

Altostratus opacus is a mid-level cloud variety characterized by a dense, gray sheet that completely obscures the sun or moon, signaling widespread stable atmospheric conditions often preceding frontal weather.

Cirrus uncinus is a high-altitude cloud species characterized by wispy, hooked filaments often called "mare's tails," signaling moisture in the upper atmosphere and impending weather changes.

A wall cloud is a sharply lowered, localized cloud formation beneath a cumulonimbus base, signaling intense storm updrafts and often preceding tornado development.

Pileus is a smooth, lens-shaped accessory cloud that forms as a cap or hood above rapidly rising convective clouds, signaling strong updrafts and often preceding vigorous thunderstorm development.

Cirrus spissatus is a dense, thick species of high-level cirrus cloud known for its ability to obscure the sun or moon, often forming from the anvils of mature thunderstorms.

Velum is a thin, horizontal veil-like accessory cloud that partially envelops or skirts the upper portion of a parent cloud, typically a towering Cumulonimbus or large Cumulus.

Mamma is a striking supplementary cloud feature characterized by rounded, pouch-like lobes hanging pendulously from the underside of a parent cloud, most often cumulonimbus, signaling turbulent atmospheric conditions.

Virga is a striking atmospheric phenomenon where precipitation falls from a cloud but evaporates or sublimates before reaching the ground, creating wispy streaks or shafts beneath the parent cloud.

Tuba is a narrow, funnel-shaped accessory cloud that extends downward from a parent cloud, often signaling intense rotation and the potential onset of severe weather such as tornadoes.

Cirrus fibratus is a high-altitude cloud species characterized by thin, fibrous, hair-like strands that stretch across the sky in delicate, wispy patterns without hooks or tufts.

Lenticular clouds are distinctive, lens-shaped clouds that typically form in the lee of mountains, recognized for their smooth, layered appearance and stationary nature.

Nimbostratus pannus is a ragged, low-level accessory cloud formed as irregular fragments beneath the main nimbostratus cloud during precipitation events.

Cirrostratus is a high-level cloud genus forming thin, translucent veils of ice crystals that often cover the sky and create halo effects around the sun or moon.

Stratus fractus is a low-level cloud species recognized by its ragged, fragmented, and irregular patches that often appear as wispy shreds beneath other cloud layers or during precipitation events.

Stratocumulus cumuliformis is a species of low-level stratocumulus cloud characterized by its distinctive heaped, cumulus-like appearance with rounded tops and relatively flat bases, often forming expansive gray or white cloud masses that partially cover the sky.

Altocumulus lenticularis is a distinctive mid-level cloud species characterized by smooth, lens-shaped formations that often resemble flying saucers, typically forming stationary layers near mountainous terrain.

Cumulonimbus calvus is a towering, dense cloud species characterized by a smooth, rounded dome-like top that signals an early stage of thunderstorm development before fibrous anvil features appear.

Cumulus congestus is a towering species of cumulus cloud characterized by its strong vertical growth and cauliflower-like appearance, often signaling atmospheric instability and the potential for developing thunderstorms.

Altocumulus is a mid-level cloud genus characterized by white or gray, patchy layers or sheets composed of rounded masses or rolls, often forming groups of small, puffy cloudlets arranged in regular patterns.

Cumulonimbus is the towering thunderstorm cloud genus known for its dramatic vertical development and capacity to produce severe weather such as heavy rain, lightning, hail, and tornadoes.

Altocumulus stratiformis is a mid-level cloud species characterized by broad, sheet-like layers of rounded cloudlets that often cover large portions of the sky in a blanket-like formation.

Cumulus humilis is a low-level cloud species known for its small, flat, and horizontally spread appearance, commonly signaling fair weather and stable atmospheric conditions.

Cumulonimbus capillatus is a towering, dense cloud species characterized by a fibrous, hair-like upper portion often forming a distinctive anvil shape, signaling mature thunderstorm activity and severe weather potential.