The Man Watching the Weather at Lake Bled

At four in the morning, Lake Bled is quiet. Then the thunder starts.

Jure Jerman, the meteorologist responsible for advising the organisers of the 2026 World Rowing Masters Regatta on whether it is safe to race, is already awake. He reaches for the weather radar and starts monitoring the weather models in the hours before dawn.

Outside, the rain is coming down. Around the lake, however, the spirits of the nearly 4,700 competitors do not seem to have dampened much. Boats are stacked three deep in the boat park. Thousands of rowers have come to Slovenia for an event expected to be the largest regatta ever held, with nearly 5,000 competitors and 20,000 racing seats.

But before any of them can race – or even take to the water for warming up – someone has to decide whether the lake is safe. That someone is Jerman.

For 32 years, Jerman has worked for Slovenia’s national weather service. When the country hosts a major sporting event, he is often somewhere nearby, trying to translate an unruly atmosphere into a decision: go, wait, or stop.

He has done it at Planica, where ski jumpers take off the K140 inrun, fly through the air for 200+ meters, and touch down on the steep landing zone. At Bled, the problem is different. Here, the athletes are on the water, exposed to wind, rain, and, most importantly, lightning.

“Thunderstorms are the biggest problem here,” Jerman says. “Lightning is something we really have to take care of.”

On a morning like this one, his day begins before most people have thought about getting out of bed.

He normally starts around 4 a.m., checking whether thunderstorms are developing nearby because racing begins early. This morning, day two of the regatta, the first sounds of thunder wake him. He opens the radar.

There are thunderstorms around the region.

Every five to 10 minutes, he checks the radar again. He watches new lightning data. Every few hours, he checks a fresh computer model. Satellite images provide another view of what is happening above the clouds.

“You really don’t want to miss some lightning indicating that the next thunderstorm is building up.”

The weather around Bled can be particularly complicated. Warm air from the Adriatic and southwesterly winds often push thunderstorms towards the Julian Alps. This week, a low-pressure zone around Bled didn’t push out the turbulent weather. Instead of passing through, it has settled over the area.  The region has one of the highest lightning probabilities in Europe.

Decisions, especially for a meteorologist, are not always straightforward.

This morning, the most active system eventually moves away from the venue. The rain remains—the cold front is still sitting over the area—but the lightning disappears from the immediate vicinity.

The rain isn’t inviting outside.  But it is not dangerous. That distinction matters.

The Forecast is Never the Whole Story

Jerman sits in front of his models and explains what they are showing.

One screen displays a sequence of radar images from the morning. Another shows a model predicting how precipitation should develop over the next few hours.

The model is not the truth, he explains. The radar is the ground truth. The job is to compare the two and work out whether the forecast is behaving as expected.

A satellite image shows a low-pressure system developing over the northern Adriatic. That system is keeping the cold front over the region longer than expected.

Meteorology is partly about knowing when your forecast is wrong.

“Sometimes it’s about correcting yourself—correcting your wishful thinking and hoping that everything is already over.”

Today is one of those days. The front looked like it would pass quickly. Instead, it stalls against the Alps. Thunderstorms linger.

No human element shows up on the radar.

“You need to understand the requirements of your customer—rowers, in this case,” Jerman says. “What are their needs? What knowledge do they need to have?”

The question is not simply whether the weather is good or bad. It is when to tell organisers to wait, and when to tell them that the water is safe.

“When do you stand up and say, ‘Guys, we have to wait,’ and when do you stay quiet?”

After 32 years, the answer is a mixture of science, experience, and, occasionally, gut feeling.

Thirty-Two Years of Change

When Jerman began working in meteorology, the internet was only beginning to reshape the profession.

Since then, weather models have become dramatically more sophisticated. High-performance computers process enormous amounts of data. Satellites and radar provide information that would have been unimaginable when he started.

Now, artificial intelligence is beginning to enter the field of meteorology.

Jerman accepts, and even welcomes, what technological advances can do. But he is also wary of what could disappear with it.

He worries about the loss of domain knowledge—the accumulated understanding that comes from years of interpreting models, observing weather and working with people who depend on the forecast.

“I believe AI can do a lot of the work we are doing now,” he says. “But, on the other hand, you need the domain knowledge.”

Especially in sport.

A computer can identify a storm. Still, someone has to explain to an organiser what it means for the people sitting in boats on a lake.

“You need people who can help the organisers decide when it’s time to go out on the water,” Jerman says, “so they feel more confident that they are not losing time waiting for the weather to improve.”

Rowing Comes to the Family

Jerman is not a rower.

But rowing has been part of his life for more than 15 years.

In 2010, he provided weather forecasting for the World Rowing Cup on Lake Bled, the first leg of that year’s World Cup series and a test event for the following year’s World Rowing Championships.

His son saw the regatta. Then he started rowing.

Jerman began travelling with him to competitions around Europe. He never took up the sport himself, but he came to appreciate what he was watching.

Now, at the biggest rowing regatta Bled has ever seen, he looks out at thousands of athletes—men and women who have continued to row long after many people would have stopped competing.

“That is actually really impressive,” he says.

It is an appropriate place for a meteorologist to find himself: not part of the race, but essential to whether it can happen.

As the rowers watch the start clock, Jerman scans the sky, keeping a watchful eye.