Chris vs. the Meltemi

Beford0816

Stuart Streuli

ATHENS--For the past few days, Chris Bedford has been doing battle with the Meltemi. Of course, the meteorologist has been doing so from the air-conditioned comfort of the U.S. Sailing team house a few hundred yards from the Agios Kosmas Olympic Sailing Center in Glyfada. His job is to keep U.S. sailors in tune with the weather and, hopefully, one step ahead of their competitors. For the past four years, Bedford has been helping the U.S. Sailing Team with weather predictions for major regattas, most of the time from his home office in Watertown, Mass. But he traveled to Greece last year for the Pre-Olympics and is on-site again for the 2004 Games. We asked Bedford to explain this punchy and unpredictable offshore breeze. The Meltemi started on Sunday and is expected to blow for a few days. What exactly is it? Basically it's a strong north to northeast wind that is common in certain weather map patterns. The short version is there's a heat low over Turkey and a high over Southeastern Europe, so it squeezes the gradient. It's sort of accelerated here by the terrain. I've heard the Meltemi is basically around all the time and it's just a matter of how strong it is? The low that is over Turkey is basically a semi-permanent feature in the summer time. So it's there all the time. So it's really a function of what the high is doing over Southeastern Europe. If, for example, that high in Europe is replaced by a low then the Meltemi is weakened and it allows the sea breeze to form. So you're always watching that thermal low over Turkey. and watching the pressure systems over Eastern Europe and how they're going to affect the pressure gradient. Often times it's just a really fine balance between the sea breeze and the Meltemi gradient and it can be a coin flip. Many Americans are used to the sea breeze being the strongest of their regular local weather patterns. Here it's the reverse. Is this a unique situation? I guess it is sort of normal in the Med because the water here warms up so much. The temperature difference between the land and the sea is not as great as it is in, say, New England. When you forecasted for America's Cup teams you had a very specific job, give them a weather picture and, most importantly, nail the first shift for a certain time and place. With as many as eight different classes sailing at once on four circles, what do you strive to provide for the U.S. Olympic sailors? I think the most important thing is not to give them an absolute forecast. I make a table up that says at 1 p.m. the wind will be here, at 2 p.m. the wind will be there, but I emphasize the fact that when they go out to the race course they should not expect to match what's on the forecast table. It's more to give them an idea of what the trends will be. I try to arm them with information they can use to make decisions on their own on the race course, give them signs to look for, trends that they can expect out of the breeze. For instance, if the breeze gets to 160 degrees and stabilizes, then how do you determine whether the next likely thing is for it to go left or right. You mentioned that with the Meltemi often it's better to play the velocity than the shifts. This breeze can shift a lot, why do you favor that approach? I think it depends on the boat. Because the wind is so strong, the shifts tend to be really short and it's hard to do much with them. Really getting into the pressure lines is where the value is in this type of breeze. In the sea breeze where the wind is light and the breeze slowly shifts and oscillates more, the shifts have a bigger impact on the fleet. In the Meltemi the shifts are kind of chaotic so chances are on four beats, three beats, whatever it is, if you've average out the fleet on the shifts they got, whether they were in their favor or not, it would be even throughout the fleet. It's just luck. Whereas the sea breeze it's more the trends that are powerful. From a weather perspective, how should a sailor approach racing in the Saronic Gulf? I think you approach it with an open mind, I don't think you get in a mindset that you always go left in this situation. You play the board a little bit more as you see it. I think the sailors that are more willing to change their strategy will do better here than those who get locked in. How do you view predicting the wind here. Is it a fun challenge for you? Every place is a challenge, I don't care where it is. This place is particular interesting because of the combination of terrain and sea breeze flows. You don't always get that, you usually have either a sea breeze flow or a terrain flow. This is an interesting combination, so it's kind of fun. I've spoken with a few U.S. sailors who want nothing to do with a forecast, they're worried that it will steer then in one direction and the breeze just isn't that predictable. Do you take that as insult? Not at all. It's totally up to them and everyone's different. Some people are way into it and other people want to go out and sail the boat. So I don't take it personally at all. OK, so how long can we expect this Meltemi to last and what do you expect for the second half of the week? I think today is the last day of the strong Meltemi. [Tuesday] morning will be still a pretty strong Meltemi, but it backs off very quickly in the afternoon. [Tuesday] afternoon they'll probably still be racing in an offshore breeze, but there might be a little bit of a sea breeze battle late in the day. Wednesday and Thursday looks like sea breeze days and then there's a little bit of resurgence in the Meltemi, not this strong, on Friday and Saturday. Is the Meltemi usually just a two- or three-day thing? Depending on the time of year they can last for 10 days. Typically, this time of year they don't last that long. But in the late spring and early summer they can blow for 10 days.