Sometimes it is difficult to learn cloud identification from still photos, because of the lack of perspective, movement, and context. For this reason, below is an attempt to make a cloud ID table that uses short movie loops. Each 20 second .AVI movie is about 3 to 4 MB, and can be viewed with an AVI player or with Quicktime.
I will gradually fill in the cloud chart with movies as the clouds occur. So for now, there are many holes in the cloud chart.
| Smooth sheets | Lumpy sheets | Other | |
| Stratiform [ layered clouds caused primarily by horizontal winds (advection) ] | |||
| High bases |
cirrostratus (cs) m1, m2, m3, m4, m5 |
cirrocumulus (cc) m1, m2, m3, m4, m5 |
cirrus (ci) m1, m2, m3, m4, m5 |
| Middle bases |
altostratus (as) m1, m2, m3, m4, m5 |
altocumulus (ac) m1, m2, m3, m4, m5 |
altocumulus castellanus (accus) m1, m2, m3, m4, m5 |
| Low cloud bases |
stratus (st) m1, m2, m3, m4, m5 |
stratocumulus (sc) m1, m2, m3, m4, m5 |
nimbostratus (ns) with widespread drizzle or light rain m1, m2, m3, m4, m5 |
| Cumuliform [ vertically-growing clouds caused by updrafts (convection). Cloud bases are in the boundary layer, relatively near the ground.] |
|
| Thunderstorms: thick clouds, with tops at or above the tropopause. | cumulonimbus (cb) m1, m2, m3, m4, m5 |
| Towering cumulus, with tops approaching the tropopause. | cumulus congestus m1, m2, m3, m4, m5 |
| Building cumulus with tops near the middle of the troposphere. | cumulus mediocris m1, m2, m3, m4, m5 |
| Fair-weather cumulus. Shallow, at the top of thermals on sunny days. | cumulus humilis (cu) m1, m2, m3, m4, m5 |
| Scud clouds. Shallow, low clouds torn by strong winds. | cumulus fractus m1, m2, m3, m4, m5 |
| Wave, Cap, and Mountain-caused Clouds | |
| Mountain waves | Lenticular (altocumulus standing lenticular) m1, m2, m3, m4, m5 |
| Cap clouds above or touching the tops of rapidly-rising cumlus towers | Pileus clouds m1, m2, m3, m4, m5 |
| Cap clouds over mountains, caused by horizontal winds hitting the mountains. These are often the first wave of a mountain wave train. | Cap clouds m1, m2, m3, m4, m5 |
| Anabatic clouds over mountains, caused by convective vertical updrafts of warm air rising off the ridge tops | Anabatic clouds m1, m2, m3, m4, m5 |
| Scarf clouds blowing off mountain tops | Banner clouds m1, m2, m3, m4, m5 |
| Breaking waves in the air | Kelvin-Helmholtz (KH waves) m1, m2, m3, m4, m5 Billow clouds m1, m2, m3, m4, m5 |
| Fog |
| Advection fog (movement of humid air by horizontal wind over a colder surface) m1, m2, m3, m4, m5 |
| Steam fog (buoyant convection, with evaporation from warm wet surface and mixing into colder air) m1, m2, m3, m4, m5 |
| Radiation fog (radiative cooling with little or no wind) m1, m2, m3, m4, m5 |
| Upslope fog (adiabatic cooling in rising air as winds are forced up over mountains) m1, m2, m3, m4, m5 |
| Precipitation (frontal) fog (as falling warm rain evaporates into cooler air below cloud base) m1, m2, m3, m4, m5 |
Copyright © 2003 by Roland Stull
Earth & Ocean Sciences Dept.
University of British Columbia
Vancouver, Canada