Answer to Question 1
Hail is hard, rounded pellets of precipitation that form in large cumulonimbus clouds during thunderstorm activity. Ice pellets grow by collecting supercooled water as they fall through the cloud, then are sent back up again with updrafts to collect more supercooled water as they fall back down. Eventually, they grow too heavy to be carried up again and fall to the ground as hailstones. The size of hailstones is governed by the strength of updrafts and the presence of droplets in the air surrounding the hailstone that can add to its size via collisions.
Answer to Question 2
Rain gauges can measure to the nearest 0.025 centimeter, and this measurement is local and accurate to trace amounts. This measurement is not predictive and requires individual readings for each rain gauge. Weather radar forecasts precipitation rather than reading the amount of precipitation. It is useful for prediciting storms and can see the extent and rate of precipitation over large geographic areas.
The skimmers or perchers and their relatives form the Libellulidae, the largest dragonfly family in
Risk Factors for Diabetes
Cell surface recognition factors
Genome size
Population size
Short form of amino acids