Meteorological Observations

Question 1

What does ground based weather radar do?

Answer 1

• Detects location and movement of water droplets
• Sends out microwave energy and listens for returning signals
• Reflectivity is due to number and size of water droplets per given volume
• Colour represents intensity

Question 2

What does airborne weather radar do?

Answer 2

Same as ground based but onboard an aircraft, has the ability to tilt to look above or below flight path

Question 3

What precipitation has the most and least reflectivity?

Answer 3

Most
- Wet hail, rain, wet snow

Least
- Dry hail, dry snow, drizzle

Question 4

On a radar display what to different colours represent?

Answer 4

Blue/green - weak (level 1) returns
Yellow/orange - moderate (level 2)
Red/magenta - strong (level 3) returns (25-50mm/hr)

Question 5

What does scalloping indicate on a weather radar?

Answer 5

Turbulence

Question 6

What is the blind alley effect and masking?

Answer 6

Strong returns can mask other areas of significant weather, black does not mean no weather threats

Question 7

What are the 2 types of satellite observations?

Answer 7

• Visible imagery

- Infrared imagery

Question 8

How does visible imagery work?

Answer 8

• Clouds reflect sunlight
• Only useful during daylight hours
• Better at detecting low cloud or fog than IR

Question 9

How does infrared imagery work?

Answer 9

• Day or night
• Colour/shading shows cloud temps
• IR is reverse negative, high clouds show brighter than low clouds

Question 10

What can satellite imagery be used to identify?

Answer 10

• Stable (flat)
• Unstable (lumpy)
• Fronts (cloud band)
• Low (cloudy)
• High (clearer)

Question 11

What other features can be seen using satellites?

Answer 11

• Dust

- Mountain waves