You hear about it every day on the TV news: “The radar” that delivers images of inclement weather systems as they approach. But what does it really show?
It’s a question about which knkx weather expert Cliff Mass gets tons of email. Clearly many people find this technology fascinating and its capabilities exciting. And the professor himself is not immune.
“Weather radar is just an amazing way to see where it’s precipitating, where it’s moving,” he said. “And if you use it wisely, you can stay dry even when you’re outside in showery conditions.”
Mass, who teaches atmospheric sciences at the University of Washington, calls the capability “really startling.”
The fascination begins with the story of how we got it, he says.
Technology Emerged From World War II
“Weather radar actually began during World War II,” said Mass. “There was radar used to watch the German planes come in to England and they started noticing that heavy showers would block the radar beam.”
So, after the war, a number of meteorologists grabbed surplus radar machines to test the technology.
“And they started playing with them and seeing what it could see. And it turned out it was really good for seeing thunderstorms, heavy showers --- anytime the precipitation was coming down pretty hard, the radar showed it quite well.”
During the 1950s, the National Weather Service put a radar network around the United States. During the 1980s, they upgraded to Doppler weather radar, which is in place right now.
“So weather radar is a way that you can see exactly where it’s raining at any particular time and there’s a new radar image every six minutes,” Mass says. “So you can animate it and really get an excellent idea of where the showers are at any particular time.”
What Can It See?
Modern radar can see rain and precipitation that comes in as water with great accuracy. It can also see snow, but the return is not as good so it’s less accurate. But it will pick up light snow, Mass says.
It also often spots migrating birds, a topic about which Mass has blogged a few times.
“At night, when the birds are flying in the sky – a lot of them like to migrate at night – the weather radar picks it up,” he says, adding that it will even pick up bugs sometimes.
“But the main use is for seeing areas of heavy precipitation,” he says.
This comes in very handy if you are engaging in weather-dependent outdoor activities, such as bike commuting – something Mass does most days. He says it’s especially useful when showers are intermittent.
“There’s often a period of 15 minutes to a half an hour when it’s not raining,” he says. “If you have that weather radar in real time, you can see exactly where the showers are. You can go out there during gaps in rain.”
If you want to get really into it, there’s one dedicated to weather radar that costs a bit, but Mass recommends it, called Radarscope.
“You can get real time radar and it shows you exactly where you are, you can animate it – it’s wonderful,” he says.
“So, there’s a variety of ways you can get at the radar imagery, because that’s in the public domain and it’s available to everyone, in real time.”
The weekly knkx feature ‘Weather with Cliff Mass’ airs every Friday at 9 a.m. immediately following ‘BirdNote’, and twice on Friday afternoons during ‘All Things Considered’. The feature is hosted by knkx Environment Reporter Bellamy Pailthorp. Cliff Mass is a University of Washington professor of atmospheric sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to a podcast of ‘Weather with Cliff Mass’ shows.