2. I am at Opening Day for the St. Louis Cardinals and weather reports from the morning hinted at the possibility of rain during the game. What type of imagery would I monitor to know if the game could be delayed by rain?

Precipitation intensity is measured by a ground-based radar that bounces radar waves off of precipitation. The Local Radar base reflectivity product is a display of echo intensity (reflectivity) measured in dBZ (decibels). Reflectivity is the amount of transmitted power returned to the radar receiver after hitting precipitation, compared to a reference power density at a distance of 1 meter from the radar antenna. Radar returns are usually described by colour or level. The colours in a radar image normally range from blue or green for weak returns, to red or magenta for very strong returns. r example, the U.S. National NEXRAD radar sites use the following scale for different levels of reflectivity:

magenta: 65 dBZ (extremely heavy precipitation, > 16 in (410 mm) per hour, but likely hail)

red: 50 dBZ (heavy precipitation of 2 in (51 mm) per hour)

yellow: 35 dBZ (moderate precipitation of 0.25 in (6.4 mm) per hour)

green: 20 dBZ (light precipitation)

Strong returns (red or magenta) may indicate not only heavy rain but also thunderstorms, hail, strong winds, or tornadoes, but they need to be interpreted carefully.