Rain and low-level snow are in the forecast for Tuesday and Wednesday in Southern California when a storm sweeps into the region.
Overnight thunderstorms mean we also have a chance of seeing hail or graupel — a form of precipitation that might often be mistaken for snow and probably isn't even recognized by your spellcheck.
Here's what to know.
What is hail?
- Hail can occur in many temperatures.
- Solid stones of ice that are usually round.
- Will bounce if small enough.
- Will not break apart easily.
- Generally larger than a pea.
What is graupel?
- Temperatures generally need to be colder than 45 degrees to occur.
- Look for small and crumbly pellets of ice.
- Graupel comes in odd shapes, not necessarily round.
- Will usually deform on contact with a surface or break apart (rarely bounces)
How does graupel form?
Graupel forms when snow crystals fall into supercooled (freezing) water droplets. The droplets then freeze to the crystal in a process called riming or accretion.
Other water droplets ‘glue’ the rimed ice crystals together.
Graupel shapes are irregular, and usually elongated because of air resistance.