Learning to observe & read the sky

10/9

Wind – review from 10/8

• Wind is produced as a result of an imbalance in air pressure.– (Usually in horizontal directions.)

• The imbalance itself is caused by a temperature difference in adjacent areas.

• Ultimately, it is thee uneven heating of the Sun that causes temperature differences and the circulation that causes pressure differences.

OBSERVE THE CLOUDS

1. Type and direction tell a lot about the upcoming weather.

2. Clouds that are white and high generally indicate good weather.

3. Clouds that are dark and low indicate storms.4. Mammatus clouds

1. Foretell thunderstorms (severe and non severe)

5. Cirrus clouds or “mare’s tails high in the sky – long tails indicate bad weather coming within 36 hours.

Mare’s tales

Altocumulus – Mackerel scales

Cumulus towers

Red Sky at night

Red sky in the morning,

Norwood, this a.m.

Gaze at the moon

Ring around the moon Meaning:• Caused by light shining

through cirrostratus clouds• Associated with warm

fronts and moisture: impending rain

Detect wind direction

Toss grass to determine wind direction

• Easterly winds can indicate an approaching storm front.

• Westerly winds mean good weather

• Strong winds indicate high pressure differences which can be a sign of approaching storms

This is a photo of a strong wind!

Observe the grass and leaves

Dew or no dew• If there is no dew, it is dry….• If there is dew on the grass

…

leaves• Look at the leaves of

deciduous trees before a storm.

• What do they do?

Make your hypothesis• Summarize your observations, and those of the first period

class.• Clouds (a.m.): mare’s tales, cirrus, altostratus• Clouds (noon):• Wind (a.m.): gusty• Wind (noon)• Sky (a.m.)• Barometric pressure (see and copy the table)• Grass, and leaves: a.m. (dew was present), leaves of

deciduous trees were “normal.”– Noon:

• WHAT IS YOUR FORECAST FOR THE NEXT 24 HOURS??

UPCOMING ASSESSMENT• Quiz/quest next week (clouds, air pressure, convection,

conduction, radiation, weather instruments, winds, Coriolis effect.)

• Weather forecast (with a partner) to lower grade• Content of forecast:

– Weather maps (local and national)– Temperature (daily high and low)– Fronts and air masses– Precipitation– Cloud cover– Wind speed and direction– More to come!!