Whether the Weather Be Fine

We’ve been holed up in Lucaya for almost a week, waiting for better weather in order to sail south towards the Berry Islands. (It feels like the Gulf Stream crossing all over again.) Every local we’ve chatted with says this has been a weird winter, with more storms and unsettled weather than usual. Most of them assume it has something to do with El Niño.

It’s been a nice place to be holed up, though. We’ve met some lovely people. There’s a family from Wisconsin headed back to Florida aboard a catamaran with two kids aged 14 and 11, so Soren and Elsa are thrilled to have playmates. Another couple on a catamaran arranged a “cocktail hour” at a picnic table on the docks, where we met many of the other current residents. There’s Noel and Suki, working to rebuild their engine. Noel is English, inspects oil drilling platforms for a living, and cruises on his sailboat when not working. He favors Tintin t-shirts and has some interesting stories about pirates he’s encountered in his line of work. Suki is from Borneo and about the kindest person imaginable. Our next-door neighbors are Kazu and Rie from Osaka, Japan. They’ve had an odyssey of challenges getting their sailboat ready for passage in Florida, including a lightning strike that fried all their electronics, and Rie getting arrested by the INS. (Kazu thought she could return to the US under a rule that, it turns out, is meant only for commercial crew. She eventually got to go home and then had to fly to the Bahamas via Canada.) They plan to sail all the way to Japan over the next seven or eight months. And there’s the catamaran family with kids, the Lefebvres, whose trip mirrors ours in many ways. We joined forces on Feb 2nd for dinner and a viewing of Groundhog Day in our cockpit, which was a blast. It’s been great to compare notes with Dan and Milissa, who started down in Tortola last fall.

You won’t be surprised to hear that the topic of weather comes up in conversation, A LOT. Our lives are run by it: whether we leave, when we leave, even where we go is determined by how fast the wind is blowing, from which direction, and how big the seas are. We also need to know how those things will change over time, not just what they’re doing right now.

There’s no shortage of data out there to guide us. On the iPad we use an app called PredictWind, which shows wind direction and strength, sea height, swell direction, and precipitation for a given area. We can overlay any combination of these factors and view them changing over time, in a sort of stop motion video that steps through one-hour increments for the next few days. We can also compare predictions from the four main forecasting models to see if they concur (a somewhat dangerous feature because it’s always tempting to believe the good ones.) It’s pretty slick.

Here in the Bahamas, though, the service that sailors seem to rely on most is not an app, but a person: Chris Parker. He’s cruised in the Bahamas and Caribbean for decades, and somewhere along the line he started sharing daily weather forecasts on Single Side Band radio. Every morning at 6:30 a.m. we fire up the SSB to listen to his report, along with hundreds (maybe thousands) of other boats. Anyone can tune in, but you can subscribe to a premium service that gives you the right to ask questions. Sometimes Chris can’t hear the person’s SSB transmitter so another boat will relay the question to him. The whole setup is super low tech but super effective — his forecasts have been shockingly reliable so far, even more so than the computer models.

The other thing that has helped us (me) understand what’s going on is learning about weather more generally. We have a terrific book that covers the basics, Eric Sloane’s Weather Book, originally published 1949. Sloane was an artist who knew a lot about the mechanics of weather and drew some marvelous little diagrams to explain things. He eventually authored a series of magazine articles, which in turn became this book. If you have even a passing interest in this stuff I highly recommend it. In fact there are two concepts I want to share right now because they blew my mind.

First, high and low pressure. I never really understood what those terms meant and only knew that high pressure correlated with sunshine and low with rain. It turns out that air pressure increases when the amount of air overhead increases — air has weight, after all. There are literally mountains of air moving about the planet, and when one passes over you the weight of all that air increases air pressure. Likewise, low pressure areas are created when there’s less air overhead, like a valley.

Remember weather maps, with their curved lines denoting changes in barometric pressure? You can read them like a topographical map since the pressure change correlates to a change in the amount of air. In other words, you’re looking at hills and valleys of air.

Wind, of course, is created when air slides off a high-pressure hill into a low-pressure valley. But it doesn’t move in a straight line. In the northern hemisphere winds spiral around high-pressure systems in a clockwise fashion, and around lows counter-clockwise. This is kind of a clutch concept for sailing because you can plan a passage before or after a system moves through to take advantage of the winds you want. I could never remember which system did what until I learned the following.

Because of the Coriolis effect, large-scale moving objects in the northern hemisphere all veer slightly to the right (clockwise); in the southern they go left. The classic example is water draining down a tub — in the northern hemisphere it drains clockwise and in the southern, counter-clockwise. This force affects wind too. So imagine this: You’re in a sled at the top of a hill, you start sliding down, and you lean your sled to the right. How will you travel? In a clockwise spiral down the hill. That’s what wind coming off a high pressure mound does in the northern hemisphere. Similarly, imagine you’re in a sled at the lip of a bowl, you head down, and once again lean to the right. You’ll start spiraling down into the bowl in a counter-clockwise direction, which is what winds in low pressure valleys (or sink holes, in the case of hurricanes) do.

HiLow Weather Sled

OMG NO WAY. Right?

At this point I think we have too much data and not enough experience. We want to be cautious but not too cautious, so we’re feeling a bit stuck. But as Kazu observed, we’re not in a hurry, right? Hopefully we’ll get out of here soon.

….

PS: Good news: I finished drafting this post in the Berry Islands! We left yesterday, February 8, a sunny Sunday. The winds weren’t quite as strong as forecast so we motor-sailed much of the time, but that’s way better than the previous time we considered leaving, which had winds gusting to 35 knots. We’re now holed up in an anchorage with another boat who shadowed us the whole time. They’re a Canadian couple who’ve been coming here for 19 winters and had a lot of advice about anchorages, which was helpful — much of the Bahamas are so shallow you need to take great care where you drop the hook. More on that in a subsequent post. 🙂

PPS: This is our first attempt posting via our Iridium GO! satellite hotspot. Plain text for now, but we’ll try to add some media when we get back to Wi-Fi.

4 Comments

  1. God, I love weather! For a while there, I was considering going back to school to become a meteorologist. But I like the idea of being an artist who renders the weather, feels the weather and just knows the weather. I’m gonna get that book…

  2. WOW!!! I just learned a lot. Thanks, Linda. Onward ho! from snow covered Illinois oxoxo w

  3. Best post yet, Linda. The Lucaya meetup with other boats sounds terrific. Nothing like comparing notes. Good that you found a cruiser weather net. Love the WX primer; you’ll never forget the basics. At the moment, you’re just north of Chub Cay where we spent our second night in The Bahamas, after Bimini. No fancy resort when we were there.

  4. Enjoy your adventures!!! Found your web site!! Kim and Jim
    Point judith ri …. Bahia mar

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