Pressure systems, fronts and weather maps

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   A student says widely spaced isobars mean strong wind. Which reply fits NOAA, by Jun's reading?

   • Correct; the spacing shows temperature
   • Correct; wide spacing means a steep gradient and very fast wind
   • No; close spacing means a steep gradient and stronger wind
   • No; the spacing shows rain amounts
2. 2.

   The four front symbols in a legend. A student says the red line with half-moons is a cold front. Which reply fits NOAA, by Kira's reading?

   • Correct; red half-moons mark cold air
   • No; that is a warm front, and a cold front is blue with triangles
   • No; it is an occluded front
   • Correct; the colors on weather maps are random and carry no meaning
3. 3.

   NOAA: 1013.25 mb equals 29.92 inches of mercury. About how many mb is 1 inch of mercury, by Luz's math?

   • About 983 mb
   • About 33.9 mb
   • About 0.03 mb
   • About 1,043 mb
4. 4.

   Model map: isobars 4 mb apart lie 80 km apart near one low and 320 km apart near another. How many times steeper is the first gradient, by Milo's math?

   • 0.25 times
   • 16 times
   • 240 times
   • 4 times
5. 5.

   A station model shows two pennants and one long barb. What is the wind speed, by Noah's math (NOAA)?

   • 60 knots
   • 110 knots
   • 102 knots
   • 120 knots
6. 6.

   A slow warm front beside a sharp cold front. A station reports a line of thunderstorms, then a wind shift to the northwest, a 15 °C drop and clearing skies (model data). What passed, by Ren's reading?

   • The center of a high
   • A stationary front
   • A cold front
   • A warm front
7. 7.

   The four front symbols in a legend. A purple line with triangles and half-moons on one side sits near an old low. What does it show, by Tala's reading (NOAA)?

   • A new cold front forming
   • A stationary front
   • A dry line
   • An occluded front, often a sign the system is mature and weakening
8. 8.

   Which summary of pressure systems fits NOAA, by Zee's reading?

   • Highs and lows both spin clockwise in the north
   • Wind blows from low pressure toward high pressure
   • Highs: sinking air, fair skies, clockwise; lows: rising air, clouds, counterclockwise
   • Highs: rising air and storms; lows: fair skies
9. 9.

   The four front symbols in a legend. Which summary of front symbols fits NOAA, by Ari's reading?

   • Each front is drawn as a plain black line
   • Cold: red half-moons; warm: blue triangles
   • Cold: blue triangles; warm: red half-moons; stationary: alternating; occluded: purple
   • Occluded: blue triangles; cold: purple
10. 10.

    Which summary of reading wind on a weather map fits NOAA, by Bo's reading?

    • Wide isobars mean strong wind; each barb counts 1 knot of wind speed
    • Close isobars mean calm; a pennant means 5 knots
    • Winds circle highs counterclockwise in the north
    • Close isobars mean strong wind; barbs count 10, 5 and 50 knots