This week's question comes from Morning Brief reader David Sanderson, who asks: "Raindrops can be very small (e.g., mist, fog), but how large can a raindrop be in its liquid state?"

Meteorologist Rob Shackelford: Do you know the moment when you’re driving in your car and it is about to start raining? The sky is that bright gray color and you almost start hearing it before you see it on your windshield. I’ve always loved those big, fat first raindrops hitting my windshield, the sound they make, and the splats they leave. They look so much bigger than they actually are.

Even before I went to school at the University of Georgia and studied to become a meteorologist, I can remember being curious about those first big raindrops. Like, what’s happening? Why are they such fat drops?

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As I found out, there are a whole bunch of different-sized drops but the smaller ones are all evaporating before they get to you. Only the biggest raindrops are the ones hitting your car. Before I explain exactly how large they can get, it helps to understand how a big raindrop is formed.

Mist and fog are fascinating because these water droplets are so small that they are not actually affected by gravity and are able to stay suspended in the air. There are particles in the atmosphere — it could be pollution, it could be dust from the Saharan desert — and then these rain droplets form around them.

These droplets are so small; they’re a tiny fraction of a millimeter. Since they don't actually fall, they are not technically raindrops.

But in the atmospheric conditions of a cloud, these droplets collide and accumulate and eventually converge into a droplet that is too heavy to stay suspended in the air and starts to fall. Once these drops get heavy enough to fall, that is when they become raindrops (since it is summer, we won't mention what happens with snow).

When they first start falling, the smaller drops won’t land because the drier air right near the surface will cause them to evaporate. And the biggest drops, as they are coming down, are more unstable and can be impacted by the atmosphere, causing them to be a little smaller than they began.

Those first big fat raindrops on your windshield? They might be around 6 millimeters in width. It’s the splat that makes them look so large. There have been studies done and the largest raindrops recorded were around 8.8 mm, maybe, possibly 10 mm wide — about the width of a pea. But those are outliers.

Do you have a question to ask the meteorologists at Weather.com? Write to us at [email protected] and we’ll pick a new question each week from readers to answer.