Monday
Monday: What Is Weather?
Rocket bursts onto the lab roof with a toolbox and a grin. "Today we open Station Rooftop," he says.
"A real weather station. Give me an hour and I will have the first forecast ready."
Raven looks up at the sky before she looks at the tools. "What do you notice first?" she asks.
Rocket stops. The air is cool. A breeze lifts the edge of his notebook. Thin clouds slide past.
Nova hovers at the railing, her sensors blinking softly. "A forecast needs a log first," she says.
"What would you write down about the air right now? Not tomorrow. Right now."
Raven is already writing: cool, breezy, thin clouds, dry. "That," Nova says, "is weather."
Weather is the state of the air
The National Weather Service defines weather as the state of the atmosphere at a given point in time.
It describes the wind, the temperature, the cloudiness, the moisture and the pressure of the air.
Weather is not the same everywhere. It changes over minutes, hours, days and weeks.
Almost all weather happens in the lowest layer of the atmosphere, called the troposphere.
This course turns the crew's lab roof into Station Rooftop, a home weather station.
Over the first weeks you will build your own from household things and keep a daily log, like the crew.
By week 12 you will read a real forecast and make one of your own.
The five things a weather log records
- Temperature: how warm or cold the air is.
- Air pressure: how hard the air presses down.
- Humidity: how much water vapor the air holds.
- Precipitation: water falling from the sky as rain, sleet, snow or hail.
- Wind: its speed and the direction it comes from.
The National Weather Service calls these its key observations. Together they describe the weather at one place and time.
Your Station Rooftop log will track the same five things, with the tools a home already has.
- Read the question.
- Tap your answer.
| Statement | True or false? |
|---|---|
| Weather can change in minutes or hours. | ? |
| Weather is the same all around the world at one time. | ? |
| Humidity is a measure of water vapor in the air. | ? |
| Precipitation includes rain, sleet, snow and hail. | ? |
Why observe at all?
Weather observers and automated stations record conditions at thousands of places every day of the year.
Some observations are made every hour. Others are made once a day.
Over time, those records show patterns. Without careful observations, no one could tell what is normal and what is unusual.
Your log works the same way. The more days you record, the more your own patterns will show.
Write four words about the air right now, the way Raven did. Which of the five key observations did you catch?
A thermometer is optional. Use a digital or alcohol one the family already has, never a mercury thermometer.
The station sits on the ground, a railing or a windowsill, never on a roof or ladder.
Great first entry. Tomorrow you will meet climate, the long view, and see how it differs from weather.