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Weather Lab 6-8 / Week 06 / Station Day
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Week 06 · Reading the Clouds

Station Day

Station Day: Family cloud watch
// How clouds form, and what their shapes tell you
⏱ about 20 min

Station Day: Family Cloud Watch

Saturday morning, the crew spreads a blanket on the flat part of the rooftop, well away from the edge, and lies back.

"Cloud watch," Raven says. "Everyone finds a cloud and names it from the chart."

"Cumulus," Rocket says at once, pointing at a puffy heap. "Flat bottom, cauliflower top."

Nova hovers above the blanket, blocking the glare from the Sun's side of the sky. "What do you notice about its base?" she asks.

"Dark," Rocket says. "Darker than the top. Because the light is coming from above and the cloud is thick."

Raven writes it down and watches the puff grow a new bulge. "It is still forming," she says. "Condensation is winning."

  1. A cloud is a visible collection of tiny water droplets or ice crystals, formed when vapor condenses onto tiny specks.
  2. Rising air expands and cools, about 5.5 degrees Fahrenheit per 1,000 feet, until it reaches its dew point.
  3. Four Latin roots build the names: cirro (curl of hair), cumulo (heap), strato (layer) and nimbo (rain).
  4. The National Weather Service sorts ten basic cloud types by height: high, middle and low.
  5. Clouds tell a story: stratus means stable air, thickening cirrostratus means a change, and cumulonimbus means a thunderstorm.
◇ FAMILY CLOUD WATCH
Lie or sit together somewhere open, with everyone's back to the Sun's part of the sky.
Each person picks one cloud and names it using the ten types from Wednesday. Say which level it is in.
Watch your cloud for five minutes. Is it growing, fading or drifting? Which is winning, condensation or evaporation?
Together, decide what story the sky is telling using Thursday's table, and write a one-line forecast for tomorrow.
For a grown-up
Cloud watching never means looking at the Sun, even through thin cloud. Pick a spot where the Sun is behind everyone.
Stay on the ground, a porch or a windowsill. The rooftop in the story is the crew's, not yours.
The cloud types and chart come from the National Weather Service, at weather.gov.
Safety first
Never look at the Sun.
If you hear thunder, go indoors and finish the watch from a window.
No roofs or ladders. Watch from the ground.
THINK IT THROUGH
  • Read the question.
  • Tap your answer.
Your cloud is a puffy heap that keeps growing a new bulge. Which is winning inside it?
A thin white veil is slowly covering the sky and a halo rings the Sun. What type is it, and what might it mean?
Why is the base of a thick cumulus cloud darker than its top?
Station Day checkTrue or false?
It is safe to glance at the Sun through a thin cloud.?
A fading cloud means evaporation is winning over condensation.?
Cumulus belongs to the low level.?
WHY THIS EXERCISESafe watching and the condensation versus evaporation idea make every cloud watch a lesson.
How many basic cloud types does the National Weather Service list? Type a number.
WHY THIS EXERCISEKnowing the count helps you check that your log uses real type names.
Draw the cloud your family watched at the start and at the end of five minutes. Label the type and what changed.
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