What’s wrong with the radar?
Is it going to rain in the next few hours? There’s an app for that. But what if the radar that feeds your app is not working?
Back in early 2017, the Government of Canada announced the replacement of its weather-radar network. A contract was awarded to purchase and install 20 new radars by March 31, 2023.
Work is complete on the Cape Breton Island and New Brunswick radars; now it’s Nova Scotia’s turn. The new instalment should be back online by mid-june.
Over the years, I’ve heard from many of you about the radar coverage across Atlantic Canada.
A few years ago, John Wonnacott from East Jordan N.S. (Shelburne County) wrote a very insightful letter about the lack of weather radar coverage in our region. He believes that we need a radar installation in southwestern Nova Scotia. It is true that many of the weather systems approach from the southwest and that the current radar network does not extend very far offshore.
The weather radar is a landbased instrument with a 360-km reach from its centre.
We currently have five weather radar towers in Atlantic Canada: Chipman, near Fredericton; Gore, near Halifax; Marion Bridge, near Sydney; Marble Mountain, in western N.L. and Holyrood, near St. John’s.
There is some overlap but some gaps, too, and very little coverage just off the southwestern tip of Nova Scotia.
In his letter, Wonnacott pointed to weather software that relies on radar data. It is true that most computer programs ingest real-time information, like radar images, and that that data is projected to produce a forecast. Since the computer interprets a lack of radar data as a lack of precipitation, the ensuing forecasts are, therefore, incorrect and misleading - if that is your only source.
These points are valid, but I believe they bring us to another important issue: computer-generated products with no human intervention. Data collected and fed into a program produces a decent product, however, local effects or not always considered.
Meteorologists have other tools to help identify the “part of the system” that sits offshore: infrared and visible satellite imagery, water vapour images, vorticity charts, buoy data and so on.
Weather apps are very convenient and increasingly accurate, but they should not replace the detailed analyses of a trained local meteorologist.
When I started to work with Environment Canada more than 30 years ago, we provided three-day public forecasts: you had to listen to the radio or watch the TV news to get them.
Today, people who rely on the weather don’t want to wait, or perhaps it’s more accurate to say they can’t wait; time is money. While I understand that, I also believe that, for a complete weather picture with finely tuned local details, it’s crucial to turn to a product that has been tailored or massaged by humans.