Final answer:
The abbreviations SG, IC, PL, GR, GS, and UP in weather forecasts stand for Snow Grains, Ice Crystals, Ice Pellets (sleet), Hail, Small Hail or Snow Pellets, and Unknown Precipitation, respectively.
Step-by-step explanation:
The abbreviations SG, IC, PL, GR, GS, and UP commonly found in weather forecasts stand for various types of precipitation that meteorologists expect to occur. Here's what each abbreviation stands for:
- SG: Snow Grains - a form of precipitation consisting of very small, opaque grains of ice. Snow grains are smaller than snow pellets and are typically found in cold climate conditions.
- IC: Ice Crystals - also known as diamond dust, ice crystals are a ground-level cloud composed of tiny ice crystals that form in clear, calm, and cold conditions.
- PL: Ice Pellets - this type of precipitation, also known as sleet, occurs when snowflakes pass through a warm layer and then a cold layer, causing them to melt and refreeze before reaching the ground.
- GR: Hail - these are balls or irregular lumps of ice that form during thunderstorms when updrafts carry raindrops into extremely cold areas of the atmosphere where they freeze.
- GS: Small Hail or Snow Pellets - it refers to precipitations that are smaller than hailstones and generally bounce when they hit the ground, often forming during thunderstorms.
- UP: Unknown Precipitation - this is when automated weather stations detect precipitation but are unable to determine the type; it is often a default code when the sensor's reading does not match any known precipitation profiles.
Meteorologists use weather maps and symbols to describe and predict weather conditions including precipitation types. The symbols associated with these abbreviations can be found on weather maps to help forecast specific types of precipitation, providing valuable information for public safety and planning.