WRC
How WRC teams predict rally weather – and why it matters so much
Every day, millions of people rely on weather forecasts — and it’s no different in the FIA World Rally Championship, where an accurate prediction can sometimes decide the outcome of a rally.
That’s precisely why WRC teams employ their own weather forecasters — often referred to as meteo crews — to provide crucial information that helps engineers and drivers make key set-up and tyre decisions. In a sport where sudden rain can make or break a weekend, being on the right setup and tyre for the conditions is everything.
But how do WRC teams predict the weather? WRC.com spoke to M-Sport Ford’s weather forecaster Heinrich Kaptein to learn more about the art of rally forecasting. Some fans may recognise Kaptein from his cameo appearances in M-Sport’s More than Machine documentary last year. Currently studying Geography at university, Kaptein is in his second year with the British squad, having been recommended by his university professor Hannes Tonisson — who is now the meteorologist at rivals Hyundai.
Kaptein’s fascination with weather began at the age of four, though he never expected his self-taught forecasting skills would one day support a WRC team.
"Basically, when I was four years old, my mother’s best friend took me outside and taught me the basics of clouds, and it just stuck with me,” said Kaptein.
“Skill-wise, you need to be good at pattern recognition and have your own gut feeling, because the weather models can feed you all sorts of data. You have to make the right assumptions from that and see if the patterns correlate with each other. I am in university right now, but I’m 95% self-taught from YouTube and just reading publications.
Kaptein: the man behind M-Sport Ford's weather calls.
© M-Sport
“Actually, being a WRC meteo hadn’t even crossed my mind until I was given an offer to do it. To be fair, I used to assume that they [the teams] would check their iPhone weather app or whatever and go from that, or call up local weather services.
“My initial thought was that I would just go into our national weather service or something like that. But when that offer came across me, I think I said yes like 10 times before I got anything else. I wasn’t that big a rally fan before, but now I live and breathe rally. I couldn’t ask for much more, to be fair. I get to see the world and get paid for doing my hobby—and work with an awesome team.”
How WRC teams predict the weather
Forecasting the weather requires detailed analysis of large amounts of live data. It’s about applying the science of weather patterns and then interpreting that data to predict what’s likely to happen at any given moment.
Kaptein analyses weather models and radar imagery from various online meteorological sources to produce daily forecasts. Sometimes, he distributes up to three updates per day to engineers and drivers—providing timely, precise information that can make all the difference in setup and tyre calls.
The process typically begins a week before the rally.
“I start looking at the model data usually a week out from the event just to prepare myself for what I could expect, and usually when I get to the event it is completely different to what the models were showing a week ago—but it is good to prepare,” he says. “I usually look out for some local meteo offices because some of their data is quite useful as well, like the radars and stuff like that. There are a bunch of different websites that provide the [weather] models and it is usually free.
“It is hard to predict [the weather] and mistakes happen all the time. But I would say it is based on two things: the region itself—are there lots of mountains and things like that?—and the amount of data I have to work with. In Kenya or Chile or places like that, I didn’t have radars or anything, so my forecasting is based off my own knowledge or satellite imagery. In Europe, the data is usually pretty good.
“It just takes years of looking at the data, and then you start to develop a gut feeling - because you need it at times. This year is easier for me as most of the places we’ve already been to and I’ve seen what the patterns are like.
“Basically, I’m sort of on my own. I feed my info mainly to the engineers, and drivers as well if there is something to mention.”
The curveballs that can hamper forecasts
As Kaptein explains, a forecast is only as good as the data available. In some locations — such as Kenya — he has to rely on more traditional methods, including visually observing the sky or, famously, climbing onto the roof of M-Sport’s service park structure (as seen in More than Machine) for a better vantage point.
“You can use the model data to an extent, but basically what I was looking out for was that there are showers and thunderstorms every single day, but you have to see how they start to grow and where they would move,” he said. “This is why I spent a lot of time outside on the container roof—because that is the best data I can get, since satellite imagery has a 20-minute delay on it.”
Such is the unpredictability of weather that even mountains of data aren’t always reliable — another challenge for forecasters.
Forecast focus: Kaptein tracks incoming weather patterns.
© M-Sport
“Croatia last year was nasty because I couldn’t trust the data I had. The radar showed widespread rain across the region and the models were saying full rain for the entire day — and nothing happened. In the afternoon the showers did develop, but they missed the stages or arrived too late. That was a horrible day.
“Of course, you feel good when everything is going according to the plan. In the end, it is the engineers that make the choices and they have a lot of different inputs: ground conditions of the stage itself and the weather. I don’t feel that much pressure anymore, but initially I did.”
What can we expect in Portugal?
When WRC.com caught up with Kaptein a week ahead of the rally, he had already begun studying the weather patterns—and early signs pointed to mixed conditions.
“For now, it seems that the recce is going to be fairly wet. It looks like it is going to dry out more towards the weekend. It is still eight days away so a lot could change, but for now the signal is it is going to be a bit drier next weekend,” said Kaptein.
However, as every rally fan knows, the weather can change in an instant. Expect plenty of eyes glued to radar maps in the service park this week as teams attempt to predict the unpredictable — and gain an edge.
