Pressure systems, fronts and weather maps

Grade 9 Science Worksheet

Circle the best answer.

1. 1.

   A pressure change of 8 mb happens over 200 km (model data). What is that per 100 km, by Esme's math?

   • 0.04 mb per 100 km
   • 4 mb per 100 km
   • 16 mb per 100 km
   • 1,600 mb per 100 km
2. 2.

   Isobars around a center rise toward it: 1016, 1020, then 1024 mb. What kind of center is it, and what weather, by Jun's reading (NOAA)?

   • A high, with rising air and strong storms
   • A front, with snow
   • A low, with rising air and rain
   • A high, with sinking air and fair skies

3. Read this first

   Use this

   A slow warm front beside a sharp cold front.

4. 3.

   NOAA: as a warm front approaches, what do the clouds and rain do, by Kira's reading?

   • A sudden line of thunderstorms, then clearing
   • Clouds lower and thicken, with hours of light to moderate rain
   • Temperatures fall sharply
   • The skies stay clear
5. 4.

   NOAA: after a cold front passes, what usually happens, by Luz's reading?

   • Winds turn south, temperatures rise and the air turns humid for days
   • Nothing changes
   • Clouds lower and thicken for days
   • Winds shift to the northwest, temperatures fall and skies clear
6. 5.

   The four front symbols in a legend. Why do occluded fronts form, by Milo's reading (NOAA)?

   • Cold fronts usually move faster and catch up to warm fronts
   • Stationary fronts speed up
   • Warm fronts move faster and catch cold fronts
   • Highs push fronts together
8. 6.

   A wind line has one pennant, one long barb and one short barb. What speed is it, by Noah's math (NOAA)?

   • 60 knots
   • 65 knots
   • 16 knots
   • 75 knots
9. 7.

   Using 1 hPa = 1 mb = 100 Pa (NOAA), what is a reading of 98,800 Pa in millibars, by Pia's math?

   Use the picture in question 6.

   • 9.88 mb
   • 988 mb
   • 9,880 mb
   • 98,800 mb
10. 8.

    A station's pressure falls from 1012 mb to 1000 mb over 6 hours (model data). What is the change per hour, and what may be coming, by Ren's math?

    • About +2 mb per hour, with a high approaching
    • About −2 mb per hour, with fair skies coming
    • About −2 mb per hour, with a low approaching
    • About −12 mb per hour, with a high approaching
12. 9.

    Without Earth's rotation, wind would blow straight from high to low. What turns it in the Northern Hemisphere, by Tala's reading (NOAA)?

    • The isobars bend it back
    • The Coriolis force turns it toward the left
    • Friction turns it to the left
    • The Coriolis force turns it to the right
13. 10.

    Which way does wind circle a Northern Hemisphere high, by Ari's reading (NOAA)?

    Use the picture in question 9.

    • Clockwise, spiraling out
    • Clockwise, spiraling in
    • Counterclockwise, spiraling in
    • Counterclockwise, spiraling out