Weather and Routing

Weather and Weather Routing Resources
Preamble and our biases	When we know as much about weather as Jim Corenman and Stan Honey, we will feel qualified to publish a lot more information on the topic here. We spend a lot of time studying weather - especially in the context of onboard forecast at sea - where on Adagio we don't have access to Internet information as we can't afford the level of Inmarsat required. Back in the late 1960s we decided to get involved in yacht racing because we believed it would accelerate ours seamanship learning curve (we think that is true, and highly recommend that to anyone planning to go cruising). With regard to weather forecasting, we believe we can accelerate our learning by working with seasoned professional weather routers on our passages. Sitting in an armchair reading a good mariner's weather book is great - but what really focuses your mind is choosing a weather window, and then managing your way through what really happens out there. Having the benefit of a professional's thinking while trying to figure out the relevant weather patterns is a superb learning opportunity. We don't think these services are expensive - rather the inverse. It is quite remarkable how much service the routers we know provide for such a small fee. Some of the resources we provide have a distinct Pacific or Oceania perspective. That is where we are and what we care about right now. If you are cruising the Red Sea, there may be much superior resources to be found. Please keep in mind that strong winds are not the worry on passages, it is the sea state. A 60kn squall tests your preparedness and seamanship, but it is 60-ft waves that might actually give you a problem. Further it is not how big the waves are, but whether they are breaking that is the real issue. Big Southern Ocean non-breaking waves can make for a thrilling ride, but properly handled aren't a danger, so long as you keep your speed under control to avoid broaching or "submarining" your bow(s). Big breaking waves are really the main threat to a small boat on passage. Fortunately, they are not very common, and with enough attention paid to weather outlook, the alert passage-maker is unlikely to ever encounter such seas. Which provokes one further comment from Adagio - we have read of (and met with) various yachts that have encountered threatening sea states. That is why the first-listed resource below is Victor Shane's Drag Device Data Base. When we read 99% of these reports, we ask ourselves "what the heck were they doing out there in that place at that time?". Of course, that doesn't directly apply to the "Queen's Birthday Storm of 1995", as conditions did not look all that scary prior to the start, though we believe the best routers or weather-hounds would have raised some alarm bells prior to the fleet leaving NZ. "Stuff happens out there", so regardless of your weather skills and resources, you and your yacht should be prepared for the worst that might happen. That said, the odds are with you if when you have mastered weather forecasting, and exploit first-class routing advice. I don't have valid statistics to quote, but believe that the maximum risk most cruising yachts encounter is when close to land, and that the big majority of stuff-ups happen when anchored. Land is hard, water is soft, stay with the boat until it sinks beneath you (or go for a yacht that has inherent buoyancy, like Adagio). Closing comment - pay attention not only to the weather outlook, but also to the currents and bottom contours you are planning to sail across. Currents contrary to the sea-state, or significant sea mounts or shoaling can produce dangerous sea-states. So don't be there when conditions aren't moderate! If a bar crossing is required, please investigate all available local knowledge before attempting the bar.
DDDB, Drag Device Data Base	Victor Shane's Drag Device Database made it possible for Steve & Dorothy to decide to go cruising on a catamaran, rather than a monohull, upon which all their 30-odd years of sailing experience were based. We should say, Victor's DDDB, plus Carl Schumacher's advice and counsel ("are you more concerned about being upside down, or being on the bottom?"). Consider this (our personal view), most yachts that have bad experiences find those challenges at anchor, or due to inter-personal crew problems. Yachts that encounter problems at sea are very rare. Yachts that encounter serious weather and sea-state problems at sea are even more rare. Yachts that attempt to moderate such severe sea-state conditions by use of a sea anchor or drogue (i.e., a drag device) are even more rare. Yachts that have encountered the union of those conditions, and filed an objective report are seriously rare. That is the challenge that Victor Shane faces as he endeavors to compile an objective report of real world experiences, and to distill from same what lessons may be inferred. Visit the site, buy the DDDB book, study it, understand and rehearse the methods described therein, and you will most likely never need to use them "in anger", but you will then be prepared and forewarned. Nobody has a "silver bullet" that will guarantee you survival of whatever you may encounter at sea. Simply, our view is that if you do not study the DDDB information carefully so as to draw your own conclusions regarding gear and strategy, then you have not done your homework. And do not conclude that with the appropriate gear and training, that you will always be comfortable. We have not personally experienced this, but cruising friends of ours have, a sea anchor may help you manage a storm you should have avoided, but it may still be bloody uncomfortable - sometimes the seas are well-organized, sometimes there are vicious cross seas. With some luck Adagio won't be reporting to DDDB on the latter case, but it does happen as it did to John & Dianne Furgeson on Never Monday on their passage from Fiji to New Zealand.
Mariner's Weather Handbook	The Dashew's weather book - if you can have only one, this is the one. Back home in NZ, we have perhaps three dozen weather books. Only two made the weight-analysis budget to come aboard Adagio. And in the case of Mariner's Weather Handbook, we could have just carried the CD-ROM. We allowed the weight because we value the ability to read and reread sections of this book comfortably. Jim Corenman taught us the importance of understanding upper level (500mb) analysis and prognosis information in 1995. Mariner's Weather Handbook is the only book we know of that addresses this topic in-depth and for our audience. We have a graduate-level weather textbook (back in NZ) that covers this essential weather-as-3D-problem topic, but this is the book that makes it practical and useable aboard.
Rick Shema, Weather Routing	Rick Shema has helped us with all of Adagio's passages so far. That we keep returning to enlist Rick's services indicates that we place a high value on his advice. As of July, 2001 Rick runs a one-man-band shop, but he delivers very personalized service, and follows-up closely on the value and accuracy of his information. Highly recommended.
Commanders Weather, Weather Routing	We have subscribed to Commanders Weather routing services on every passage so far. You ask, "why do you use TWO routing services?". The simple answer is we have a lot to learn. Further, it is much easier to assess how the whole interaction with a router works for you personally when you have inputs from both routers on the same passage. Weather forecasting is not a 100% thing, so our view is that if try router X on some passages, and router Y on others, it can be very difficult to figure out who is giving you the best odds on any given future passage. Commanders Weather is bigger, more deeply-staffed organization than Rick Shema's. That means you may be talking to different meteorologist on different days. Regardless, we have found their service to be excellent, and their forecasts to be accurate, so we will continue to use them. Highly recommended.
FNMOC Model	This US Navy medium range forecast model may be the most accurate for the South Pacific areas with which we've been concerned, although we can't comment on the rest of the planet. The US Navy gives time=0 data which I find useful to check model initialization.
ECMWF Model	This is another model we look at regularly, from the European Centre for Medium-Range Weather Forecasts. It is particularly useful for studying the 500mb situation, as they give hemisphere view options. This makes it much easier to study long and short-wave trends. I don't know why, but they don't publish time=0 data on their public website, at present you can see days 3 to 6.
Oceanweather, Global Sea State	This is a commercial site with some interesting free resources. Among other resources, is this global sea-state model. It won't tell you whether you have a weather window, but it will tell you what is happening today. And if you study this model over a period of time it will give you useful info about what can happen where you are planning to go.