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SIGHTINGS — continued

we've got a feeling about the weather

The Delta Doo Dah has no official events scheduled for July and will enter a DIY phase. Many of our fleet members will find suitable anchorages from which to view the Hilton family's fireworks on July 4 at Mandeville Tip on the San Joaquin. We invite Delta explorers to let us know about their travels; we can be reached by email at chris@latitude38.com. Delta Doo Dah registration is open through August, and it's free; learn more and sign up at www.deltadoodah.com. — chris

LATITUDE / CHRIS

This is what we expect to see every September at the Rolex Big Boat Series: knockdowns, roundups, and general carnage. So for those semi-fluky years when we see 8 to 10 knots or even glass, we start to wonder — without fully understanding the phenomenon — if climate change is playing a role. While we believe in science and data, as sailors, it's impossible not to be influenced by our gut feelings.

Are the winds getting lighter in California? This is a serious and common query we hear from our readers, and a logical question given the world's changing climate. At least a few sailors have told us that they believe the Big Boat Series — held each September — has seen lighter conditions for several years in a row. So has there been a quantifiable change in the wind? We decided to take a semi-scientific look, explore our 'gut feelings' about the wind, and talk to an expert: "The wind climate is complicated, and I think the human memory is short and nostalgic," said Mike Dvorak, a wind forecaster and founder and owner of Sail Tactics. It's easy to mis- or overinterpret the weather, especially when it doesn't behave the way you want. If a regatta famous for its big winds has uncharacteristically light air, it's a little disappointing. If you have two years in a row of fluky conditions, then you might start to wonder just what the hell is going on with the planet (the same applies, by the way, to all sports dependent on the weather). Consider this report we posted from the 2016 BBS. "After a windy and chilly Thursday and Friday, and an even windier Saturday (30+ knots of breeze were reported), Sunday dawned brilliant, warm and with a suspicious amount of east in what little breeze fluttered the flags at St. Francis Yacht Club. By noon the easterly, a harbinger of the winter sailing season to come, had died and enough of a westerly had filled in through the Golden Gate to begin starting sequences." It's normal to think that something strange is happening to the planet when ordinary (but ill-timed) fluctuations in weather happen to fall on a weekend when we all want it to blow. After all, the climate is changing. "I think sailors are always looking for a way to understand their environment," Dvorak said. "It's natural to wonder if climate change is causing wind to be lighter." Seeking some hard data, we looked at wind averages as measured at San Francisco International Airport from 1948 to 2017. For the sake of expedience, and in keeping with our theme, we only looked at wind speeds for the month of September from every other year. This is by no means a scientific analysis, but might offer an empirical glimpse to contrast with our gut feelings. Since 1948, windspeed averages in the month of September have ranged between about 10.5 miles per hour to 12.5. While the 50s and 60s saw wind strengths about one-mileper-hour stronger compared to the following decades, averages have remained fairly consistent, according to our journalists-doing-math analysis. In SoCal, David Smyth, the president of Westlawn Institute of Marine Technology, said that after having a feeling that the winds were getting lighter, he looked at some historical data "to see if there was any truth to the feeling. I did not find anything unimpeachable, so I am putting it down to perception. Perhaps the fact that when I was younger, I simply sailed almost every single day. Now, I choose the day. Perhaps I keep choosing more calm days. But there are certainly changes happening in the climate, and it should appear as differences in wind. So the question might be: What is the actual signal of climate change in the wind data? I will gamble beer money that there is a signal in the wind data." According to Mike Dvorak, climate change should technically cause stronger winds in the summer. "In a warming planet, you would actually expect the seabreeze — driven by the differential heating between the land and sea — to get stronger initially. The water warming will lag the land heating and initially (now) drive a stronger seabreeze. But there are all kinds of other phenomena that could change that first-order effect." In other words, we don't have an answer as to how the winds are changing, and how climate change may or may not be driving such changes. But we have a feeling. If you have strong feelings on this subject, please email us at editorial@latitude38.com. — tim June, 2018 •

Latitude 38

• Page 73

Latitude 38 June 2018  

The June 2018 issue of the West's premier sailing and marine magazine.

Latitude 38 June 2018  

The June 2018 issue of the West's premier sailing and marine magazine.