Man's physical universe

xanabras

which ice will form.

WEATHER-FORECASTING 273

Weather predictions and observations made while

in flight enable the pilot to know when to expect ice formation.

Weather-forecasting Benefits Man in Many Ways.

Warnings of storms are displayed at more than four hundred points

along the coasts and the Great Lakes. A white flag means fair weather,

a square dark-blue flag means rain or snow, while a red flag with a

black center is the signal to prepare for a violent storm. Two such

flags give warning of the dreaded hurricanes. Such warnings enable

vessels at sea to prepare for the hurricane as far as possible or make for

the nearest port.

the danger is over.

Millions of dollars are saved by detaining ships until

Frost warnings are very important to market gardeners, fruit-,

tobacco-, and cranberry-growers, for they are thus enabled to prepare

to save their crops by the use of smudge pots and other means. Transportation

companies are enabled to protect perishable shipments en

route or to refuse to accept such products for shipment until the danger

is past.

Warnings of snowstorms enable highway departments and railroads

to be ready with snowplows and decrease or halt traffic if necessary.

Sheep and cattle ranches must prepare to protect their livestock against

blizzards and heavy snows. Week-end winter-sport carnivals are

planned and called off on the basis of weather forecasts.

One of the most important services of the Weather Bureau is that

rendered to aerial transportation. The United States Weather Bureau

maintains about fifty airport weather stations, while a great many

more airports maintain their own weather service.

STUDY QUESTIONS

1 What data are required for successful weather prediction?

2. How far ahead may the weather be fairly reliably predicted today?

3. What is meant by air-mass analysis? Of what value is it?

4. Give a few examples to show the value of weather prediction.

5. What are cyclones and anticyclones?

6. What does a pronounced barometric change indicate? Give a reason for

your answer.

7. Discuss the value of the observation of clouds in weather prediction.

8. What causes the ring around the moon? What is its significance?

9. Why is it difficult to forecast weather?

10.

11.

How are data concerning air masses at high altitudes collected?

Why should airplane pilots avoid thunderstorms?

12. What causes ice to form on airplane wings?

13. What is the ceiling, and how is it measured?

14. What is the radiosonde?

More magazines by this user
Similar magazines