CBM Radar & Satellite Meteorology 5

Question 1

The radar reflectivity factor Z for Rayleigh scattering is proportional to the drop diameter raised to which power?

Accepted Answer

Sixth power (D^6)

Answer

Z is the sum of D^6 over particles in a volume, so a few large drops dominate the return.

Question 2

Why do forecasters use storm-relative velocity (SRM) instead of base velocity when looking for mesocyclones?

Accepted Answer

Removing the storm's motion makes rotational couplets easier to see

Answer

Subtracting storm motion removes the bulk flow, revealing the rotation pattern within the storm.

Question 3

On a WSR-88D, the Clear Air Mode volume coverage patterns (such as VCP 31/32/35) are mainly designed to:

Accepted Answer

Use slower scans to increase sensitivity for detecting light echoes and boundaries

Answer

Clear Air VCPs use fewer elevation angles and longer dwell time to detect weak returns such as light snow and outflow boundaries.

Question 4

In GOES infrared imagery, which brightness temperature generally indicates the highest cloud tops?

Accepted Answer

The coldest brightness temperatures

Answer

Temperature usually decreases with height in the troposphere, so the coldest cloud tops are the highest.

Question 5

At night, which GOES product is commonly used to detect fog and low stratus?

Accepted Answer

The difference between the 3.9 µm shortwave IR and 10.3 µm longwave IR bands

Answer

Water droplets emit less efficiently at 3.9 µm than at 10.3 µm, so liquid cloud stands out in the difference.

CBM - Certified Broadcast Meteorologist Practice Test