Separate heaps with clear edges?
Yes: Cumulus or Cumulonimbus.
No: continue to coverage.
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Quick identification key
A broad layer or veil?
Low + lumpy: Stratocumulus.
Featureless + raining: Nimbostratus.
High + translucent: Cirrostratus.
Thin, white, detached wisps high above?
Likely Cirrus. If it forms a milky veil with a halo, choose Cirrostratus.
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Six clouds to know
Cumulus
- Look for
- Bright cauliflower tops and a flat, darker base.
- Usually says
- Rising warm air; often settled if growth stays modest.
Watch next: Are tops building upward faster than they spread?
Cumulonimbus
- Look for
- A dark base, huge tower, and often an anvil-shaped top.
- Usually says
- Heavy showers, lightning, gusts, or hail are possible.
Watch next: Track darkening base, thunder, and the storm's movement. Seek shelter early.
Stratocumulus
- Look for
- Low rolls or rounded patches joined into a broad sheet.
- Usually says
- Stable, dull weather; perhaps drizzle, rarely heavy rain.
Watch next: Are gaps closing and the base becoming smoother and darker?
Nimbostratus
- Look for
- A thick, shapeless gray deck that hides the sun.
- Usually says
- Widespread, steady rain or snow rather than showers.
Watch next: Note visibility, steady precipitation, and whether the ceiling lowers.
Cirrus
- Look for
- Fine white feathers, hooks, or mares' tails.
- Usually says
- Fair now, but a distant weather change may be approaching.
Watch next: Are wisps multiplying, lowering, or spreading into a veil?
Cirrostratus
- Look for
- A pale sheet over most of the sky, sometimes with a sun or moon halo.
- Usually says
- Moisture is increasing aloft; a front may arrive within a day.
Watch next: Does the veil thicken and lower while the halo fades?
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Compare at a glance
| Cloud | Form | Sky level | Precipitation clue | Best distinction |
|---|---|---|---|---|
| Cumulus | Detached heap | Low | Usually none | Flat base, crisp top |
| Cumulonimbus | Tall tower / anvil | Low to very high | Heavy, showery | Strong vertical growth |
| Stratocumulus | Lumpy sheet | Low | None or drizzle | Joined rolls with gaps |
| Nimbostratus | Thick gray sheet | Low to middle | Steady rain or snow | Sun hidden, no towers |
| Cirrus | Detached fibers | High | None at ground | Fine hooks and streaks |
| Cirrostratus | Thin veil | High | None at ground | Halo possible |
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