How forecasts are made and why they are uncertain

Grade 9 Science Worksheet

Circle the best answer.

1. 1.

   A city has 10 forecast spots, each with a 40% chance of rain (model data). About how many spots would you expect to get rain, by Esme's math?

   • Each of the 10
   • About 4
   • About 40
   • About 0.4

2. Read this first

   Forecast accuracy (NOAA)

   Forecast length	About how often right
   5 days	90%
   7 days	80%
   10 days or more	about 50%

3. 2.

   Using the table, how much accuracy is lost going from a 5-day to a 10-day forecast, by Kira's math?

   • About 40 percentage points
   • About 50 percentage points
   • Zero; accuracy holds
   • About 10 percentage points
4. 3.

   A planner needs a forecast right at least 80% of the time (model need). Up to about how many days ahead does the table support, by Luz's reading?

   • About 10 days
   • About 7 days
   • About 30 days
   • About 1 day at most
5. 4.

   NOAA: models are generally accurate out about four days; after that, run-to-run differences grow. What should a day-8 forecast do, by Milo's reading?

   • Skip new observations
   • Show lower confidence, or a range
   • State the day-8 weather as certain
   • Use last year's weather instead
7. 5.

   NOAA: a 6 × 6 grid has 36 points and a 3 × 3 grid has 9 for the same area. How many times the computing does the finer grid need, by Noah's math?

   • 2 times
   • 4 times
   • 27 times
   • 36 times
8. 6.

   Why does a finer grid show more detail, by Pia's reading (NOAA)?

   Use the picture in question 5.

   • Finer grids need less computing
   • Grids set the climate normals
   • Fewer points make sharper forecasts
   • More grid points cover the same area, so smaller features show
9. 7.

   NOAA: smaller time steps make models more accurate. What is the trade-off, by Ren's reading?

   Use the picture in question 5.

   • They need less computing
   • They forecast climate instead
   • They need more computations
   • They skip the starting data
11. 8.

    NOAA: the Dallas/Fort Worth normal rainfall is 36.14 inches; one record year got 62.61 inches. How far above normal was that, by Tala's math?

    • About 36.14 inches
    • About 26.47 inches
    • About 1.73 inches
    • About 98.75 inches
12. 9.

    Why does one record-wet year barely move a 30-year normal, by Zee's reading (NOAA)?

    Use the picture in question 8.

    • Climate is each day's weather
    • The normal averages 30 years, so one year is a small part
    • Normals ignore rainfall
    • Normals reset each year
13. 10.

    A 30-year average is 36.14 inches a year, and one year comes in 26.47 inches above it. About how much does that one year raise the 30-year average, by Ari's math?

    Use the picture in question 8.

    • About 0.88 inch
    • About 8.8 inches
    • About 26.47 inches
    • About 0.088 inch