A pedestrian walks down South Fourth Street as a thunderstorm eases up on Tuesday, July 3.It’s possible for a lot of rain to fall in a short time because of a cloudburst. Learn more about them as LPM’s Bill Burton talks with WAVE 3’s Tawana Andrew in the latest Science Behind the Forecast.This transcript was edited for clarity and brevityBill Burton: It's time for us to take a look at the science behind the forecast. As I'm joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.Tawana Andrew: Good morning. Today we're answering a listener's question. Stephanie asked me if rainfall always had to start light, or if it could just be heavy. And woo, is there a specific meteorological term just for that same scenario.BB: We'll answer the question for Stephanie and for everyone. What is the answer?TA: It's a cloudburst. The American Meteorological Society defines a cloud burst as any sudden and heavy fall of rain, almost always of the shower type.BB: Shower type. I like that.TA: They made it complicated. Basically, it's heavy rain in a short amount of time, that's really what we're looking at. In some parts of the world, there is some unofficial criteria for it, and that's usually when you see rainfall rates equal to or heavier than 3.94 inches of rain per hour.BB: That is a lot of rain.TA: That is a lot of rain. Cloudbursts are more likely in hilly and mountainous regions due to what's called orographic lift. During orographic lifting, air is forced up the side of a mountain or a hill, and it cools as it climbs. If there's enough cooling, you get clouds forming, and eventually precipitation forms within these clouds. However, you have that consistent air pushing up the mountain, keeping all of that moisture, all of that precipitation, elevated within these cumulonimbus clouds. These can sustain pretty large rain droplets as that updraft, that wind, keeps that rainfall elevated. But eventually what goes up has to come down, right?BB: I've heard that before.TA: Eventually that rain does come down, but it does so all at once over a very localized area. If you have that much rain in a short amount of time that can lead to flooding. Cloudbursts can be pretty scary and dramatic as they move through an area. Of course, you know me, I'm a nerd, so I had to go into the data. I found that a rain gauge in Panama saw 2.47 inches of rainfall in three minutes.BB: Three inches of rain in three minutes? That's a little bit too intense for me, thank you.TA: Yeah, there was one that was more dramatic on the island of Guadalupe in the Caribbean, they saw 1.5 inches of rainfall in a minute.BB: That is just way too intense. Anybody who happened to have an umbrella up at that point, well, that's not going to help them.TA: That umbrella is going inside out and is just going to be tattered at that point. That's a lot of rain in a short amount of time. And unfortunately, our warming climate may actually lead to more cloud bursts. Some recent studies have forecasted an increase in the number of extreme rainfall days in the Midwest, Northwest, and the Northeast. Because, remember, our atmosphere can hold 4% more water vapor for every one degree of Fahrenheit rise in temperature that we see on average. And that's on average for some parts of the world. That's 7% for some parts of the world, it's 20% for others. It just depends. ...read more read less