1. a Weather Station Model Is Shown Below

1. A weather station model is shown below.

What is the barometric pressure indicated by this station model? A) 0.029 mb B) 902.9 mb C) 1002.9 mb D) 1029.0 mb

2. Which weather station model indicates the highest relative humidity? A) B) C) D)

3. Which weather station model represents a location where a thunderstorm is occurring? A) B) C) D)

4. Which weather station model indicates the greatest probability of precipitation? A) B) C) D)

5. Which weather station model shows the highest relative humidity? A) B) C) D) 6. Which station model represents a location that is currently receiving some form of precipitation? A) B) C) D)

7. Which weather-station model shows an air pressure of 993.4 millibars? A) B) C) D)

8. Which station model shows the correct form for indicating a northwest wind at 25 knots and an air pressure of 1023.7 mb? A) B) C) D)

9. On which station model would the present weather symbol * most likely be found? A) B) C) D) 10. Base your answer to the following question on the graphs below, which show the noontime air temperatures, dewpoint temperatures, and air pressures recorded at a location in New York State.

Which partial weather station model best represents the conditions for Sunday at noon? A) B) C) D)

11. Base your answer to the following question on the data table below, which shows the air pressures and air temperatures collected by nine observers at different elevations on the same side of a high mountain. The data were collected at 12:00 noon on a clear, calm day.

Which station model best represents weather conditions at station 1 at this time? A) B) C) D)

12. When the dry-bulb reading of a thermometer is 20ºC and the wet-bulb reading is 11ºC, the relative humidity is approximately A) 17% B) 30% C) 33% D) 55% 13. The station model below shows the weather conditions at Houston, Texas, at 9 a.m. on a particular day in June.

What was the barometric pressure at Houston 3 hours earlier on that day? A) 997.1 mb B) 999.7 mb C) 1003.3 mb D) 1009.1 mb

14. A parcel of air has a dry-bulb temperature of 16ºC and a wet-bulb temperature of 10ºC. What are the dewpoint and relative humidity of the air? A) -5ºC dewpoint and 33% relative humidity B) -5ºC dewpoint and 45% relative humidity C) 4ºC dewpoint and 33% relative humidity D) 4ºC dewpoint and 45% relative humidity

15. What is the wet-bulb temperature when the air temperature is 16ºC and the relative humidity is 71%? A) 11ºC B) 13ºC C) 3ºC D) 19ºC

16. When the dry-bulb temperature is 14°C and the wet-bulb temperature is 8°C, the relative humidity is A) 6% B) 22% C) 25% D) 41%

17. What is the relative humidity when the air temperature is 29°C and the wet-bulb temperature is 23°C? A) 6% B) 20% C) 54% D) 60% 18. The weather instrument below can be used to determine relative humidity.

Based on the temperatures shown, the relative humidity is A) 19% B) 2% C) 33% D) 40%

19. An observer measured the air temperature and the dewpoint and found the difference between them to be 12°C. One hour later, the difference between the air temperature and the dewpoint was found to be 4°C. Which statement best describes the changes that were occurring? A) The relative humidity was decreasing and the chance of precipitation was decreasing. B) The relative humidity was decreasing and the chance of precipitation was increasing. C) The relative humidity was increasing and the chance of precipitation was decreasing. D) The relative humidity was increasing and the chance of precipitation was increasing.

20. What is the approximate dewpoint temperature when the dry-bulb reading is 14ºC and the wet-bulb reading is 8ºC? A) 1ºC B) 6ºC C) –6ºC D) –9ºC 21. The weather instrument shown below can be used to determine dewpoint.

Based on the values shown, the dewpoint is A) –5°C B) 2°C C) 8°C D) 33°C

22. What is the approximate dewpoint temperature if the dry-bulb temperature is 13ºC and the wet-bulb temperature is 10ºC? A) 7ºC B) 10ºC C) 3ºC D) -25ºC

23. What is the dewpoint temperature when the dry-bulb temperature is 14°C and the wet-bulb temperature is 10°C? A) -17°C B) 6°C C) 3°C D) 4°C

24. What is the approximate dewpoint temperature when the dry-bulb temperature is 18ºC and the wet-bulb temperature is 14.5ºC? A) 8.0ºC B) 10.ºC C) 11ºC D) 12ºC 25. If the air temperature were 20ºC, which dewpoint temperature would indicate the highest water vapor content? A) 18ºC B) 15ºC C) 10ºC D) 0ºC

26. What is the approximate relative humidity if the dry-bulb temperature is 11ºC and the dewpoint temperature is 1ºC? A) 20% B) 35% C) 50% D) 65% Answer Key Humidity and Station Models

1. C 2. B 3. C 4. C 5. B 6. A 7. C 8. B 9. C 10. A 11. A 12. B 13. C 14. D 15. B 16. D 17. D 18. C 19. D 20. A 21. B 22. A 23. B 24. D 25. A 26. C