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| Hannah on Helia, just before departure |
Fall on the US East Coast is always a difficult time for weather forecasting, and this year was perhaps the best (or worst, depending on your perspective) example of that. The challenge in planning an offshore voyage this time of year is the tight window between hurricane season and the winter weather pattern. Insurance companies won't let most yachts south of Cape Hatteras before November 1 (and they probably wouldn't want to be there anyway), but the longer you wait, the greater the chances of running into a big nor'easter offshore.
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| The 'Lorenz Attractor', the graphic representation of chaos theory, named for Edward Lorenz. He stumbled upon the simple equation in the 60s by accident. His field? Meteorology. |
In 2011, Hurricane Sean threw a monkey wrench in the program at Hampton, delaying departure by five days. It was the classic late-season Hurricane, odd only for the fact that it actually formed outside the tropics. I wrote a piece for Yacht Essentials magazine about chaos theory and how it applies to ocean sailing. In very basic terms, chaos theory is the idea that complex systems are inherently unpredictable, and furthermore, that the dynamic forces within those systems cause drastically different outcomes with almost indistinguishable differences in input. For example, take the factors that create weather - temperature, pressure, humidity, etc. A tiny increase in the decimal place of only one of those input parameters can lead to wildly different outcomes in the resultant weather system.
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| The predicted weather from last year, advanced out by a week. Notice a small low east of Florida.... |
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| The actual weather for the same date as above - the extra-tropical storm Sean. |
Sean provided a perfect example of that in real life, and I illustrated it for my article using GRIB files. One of the coolest things about downloading GRIBs is that the computer automatically saves each download. On my machine, it produces a forecast of seven days. I just happened to be downloading GRIB forecasts leading up to the start of last year's 1500 - the one taken a week before Sean formed indicated no such storm on it's 7th day of predictions. And sure enough, the one downloaded the day Sean formed showed a hurricane. Chaos theory illustrated. (To make it even weirder, prior to Sean, the NE was given a Halloween dumping of snow - several yachts reported shoveling snow off their decks in Long Island Sound just to make the start on time. And then to be delayed by a tropical system…!?)
So what about this year? Sandy gave us our late season hurricane, that's for sure. It complicated matters for us in Hampton because about 8 of the yachts were hunkered down on the Chesapeake (mostly in Annapolis), and owners were worried about their houses flooding. Several crews flew out from Hampton to tend to their shoreside homes, only to find themselves stranded as far afield as Toronto after a bunch of flights got canceled. One yacht was safely moored in the Hudson when the storm hit. They escaped unscathed (the town of Haverstraw didn't), but they missed the start of the rally thanks to New York Harbor being closed to recreational traffic. They were literally stuck. But the fleet rallied (hehe) and made it to Hampton by Friday in time for the safety lecture and liferaft demonstration.
By Thursday evening it was apparent that another weather system was forming, this time looking more like the typical winter weather pattern. A nor'easter was forecast to brew over Georgia and offshore of South Carolina, moving NE and strengthening significantly. I did a quick plot on the GRIB map, marking points at 120-mile increments along the rhumb line (a conservative 5-knot daily average), and determined that the fleet, by leaving early, should be well enough south and east of the center of low pressure to avoid the worst of the weather. They'd have a short period of headwinds, but nothing serious. And best case scenario, they'd get beam-reaching winds in the 20s halfway to Tortola.
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| The weather at yesterday's start - perfect NW winds for the Gulf Stream crossing. |
Privately, we in the Rally Office were already contemplating an early departure by Thursday. If we missed this window, it looked to be at least five days until another one opened up, and even then, that was just a guess (remember that chaos theory?). Looking at it from the perspective of a delivery skipper, I felt like Friday or Saturday was the day to go (indeed my friend Micah departed on the Swan 56 he was taking to St. Thomas on Thursday).
On Friday morning we started speaking privately to a few rally veterans and a few other yachts to gauge the feeling within the fleet. Rally vets Rick & Julie Palm, and Miles & Anne Poor agreed that now was the time to go, as did their own private weather routers. By noon, during Davis Murray and Peter Burch's liferaft demo, I made the announcement that pending another look at the forecast on Saturday morning, we'd be giving the yachts the option to depart under a 'rolling start' as soon as they felt they were ready following the skipper's briefing and the issuing of the Yellowbrick GPS trackers. Everyone was enthusiastic. By Saturday morning it was official - we'd be leaving early, and the ARC Bahamas fleet would sail offshore to Beaufort and wait out the weather window there (the low was forecast to from directly over the Bahamas-fleet rhumb line on Tuesday).
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| The current weather picture as of 2200 Sunday...note the 5-knot plots for the BVI and Bahamas fleet, and the current positions of the first and last boat at sea (Habits and Club Carp) |
The Skipper's Briefing was standing room only as usual, and we breezed over the starting line sequence thanks to the change in plans. Yachts in the fun-competitive Cruising Class would take their own times as they crossed the Bay Bridge Tunnel and headed into the Atlantic, the same point at which motoring hours would start to count against the World Cruising Club handicaps. The Gulfstream analysis was straightforward as well, the fleet looking to catch a favorable eddy once they cross it. We did a thorough analysis of the weather, issued the trackers and the event officially started.
The last yacht to head to sea late last evening was 1500 vet Club Carp, almost exactly 24 hours ago (it's 10:12pm as I write…), and the big Habits of Health is leading the fleet across the Gulf Stream. They're on track to beat the 5-knot estimate, and should be sailing in about 20 knots of wind from the SW right now, if the GRIBs are accurate, perfect beam-reaching conditions on the rhumb-line to Tortola. The first little low will be passing them tomorrow - and giving them fresh northerlies for a day or so to speed south on - and the weather we looked to avoid is predicted to start forming in earnest on Tuesday.
Here's a quick note we just received on the 1500 website from the crew of Escapde:
"One of Jim Underwood's friends suggested we toss a dozen red roses into the sea to pay tribute to those on the HMS Bounty. As we entered the gulf stream just south of Hatteras, we had a moment of silence and prayer, then did just that."
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| Pictured are Jim, Neil and Shaun. Photo take by Dietmar on Escapade |
I'll be watching with a close eye on the weather this week - follow the fleet online at http://www.worldcruising.com/carib1500/viewer.aspx.
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